WO2023001026A1 - Driving assembly and control method therefor - Google Patents

Abstract

The embodiments of the present application relate to the technical field of charging. Disclosed are a driving assembly and a control method therefor, by means of which electromagnetic interference can be reduced, thereby reducing the impacts of EMC on the safe operation of a vehicle. The specific solution is as follows: the driving assembly comprises a two-level inverter circuit, a first filtering magnetic ring and an electric motor coil, wherein a first input end and a second input end of the two-level inverter circuit are respectively used for connecting to the positive electrode and the negative electrode of a battery pack in a coupled manner, and the first input end of the two-level inverter circuit is further used for connecting to the positive electrode of a direct-current power source in a coupled manner; a three-phase output end of the two-level inverter circuit is respectively coupled to three ends of the electric motor coil by means of the first filtering magnetic ring, and before passing through the first filtering magnetic ring, a first output end in the three-phase output end of the two-level inverter circuit is used for connecting to the negative electrode of the direct-current power source in a coupled manner; when excitation is performed on the electric motor coil, the directions of a current passing through the first filtering magnetic ring twice are opposite to each other; and when the battery pack is being charged, the directions of the current passing through the first filtering magnetic ring twice are also opposite to each other.

Description

A kind of driving assembly and its control method

This application claims the priority of the Chinese patent application with the application number 202110815614.5 and the application title "a drive assembly and its control method" submitted to the State Intellectual Property Office on July 19, 2021, the entire contents of which are incorporated by reference In this application.

technical field

The embodiments of the present application relate to the technical field of charging, and in particular to a drive assembly and a control method thereof.

Background technique

With the improvement of people's awareness of environmental protection, electric vehicles have been favored by the majority of users. When users choose electric vehicles, the battery life of the vehicles is an important factor that users consider. In order to improve the battery life of electric vehicles, the battery system of electric vehicles can use a high-voltage battery system. However, most of the charging piles currently on the market are low-voltage charging piles, which cannot charge the high-voltage battery system. Therefore, the boost charging function can be realized through power devices such as motor coils and motor control units (MCUs) in electric vehicles, so that low-voltage charging piles can charge high-voltage battery systems.

However, when power devices such as motor coils and MCUs are used to realize the boost charging function, the electromagnetic interference of the charging system is relatively large, which will affect the electromagnetic compatibility (EMC) of electric vehicles and the safe operation of vehicles.

Contents of the invention

Embodiments of the present application provide a drive assembly and a control method thereof, which can reduce electromagnetic interference and reduce the impact of EMC on safe operation of a vehicle.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

According to the first aspect of the embodiments of the present application, a drive assembly is provided, the drive assembly includes a two-level inverter circuit, a first filter magnetic ring, and a motor coil; the first input end of the two-level inverter circuit and The second input terminal is respectively used for coupling connection with the positive pole and the negative pole of the battery pack, and the first input terminal of the two-level inverter circuit is also used for coupling connection with the positive pole of the DC power supply. The three-phase output terminals of the two-level inverter circuit are respectively coupled to the three terminals of the motor coil through the first filter magnetic ring, and the first output terminal of the three-phase output terminals of the two-level inverter circuit is passed through the first filter magnetic ring. Before the ring, it is used to couple with the negative pole of the DC power supply. The two-level inverter circuit includes a first group of switching tubes and a second group of switching tubes, and the first group of switching tubes and the second group of switching tubes respectively include one or more switching tubes. When the motor coil is excited, the current flows out from the positive pole of the DC power supply, passes through the first group of switch tubes, the first filter magnetic ring, and the motor coil in the two-level inverter circuit, and passes through the first filter magnetic ring again. Return to the negative terminal of the DC power supply. When charging the battery pack, the current flows out from the positive pole of the DC power supply, passes through the battery pack, the second group of switch tubes in the two-level inverter circuit, the first filter magnetic ring, the motor coil, and passes through the first filter magnetic ring again After that, it flows back to the negative pole of the DC power supply.

Based on this scheme, when the motor coil is excited and the battery pack is charged, the current will pass through the first filter magnetic ring twice, and according to the circuit of the motor coil excitation process and the battery pack charging process, the current passes through the first time The direction of the first filter magnetic ring is opposite to the direction in which the current passes through the first filter magnetic ring for the second time. Therefore, the magnetic flux generated on the first filter magnetic ring can cancel each other out, and the first filter magnetic ring will not be saturated, which can reduce the Small electromagnetic interference, reducing the impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance. Moreover, in this solution, when the motor coil is excited and the battery pack is charged, the circuits of the excitation process and the charging process are integrated inside the drive assembly. Since the metal shell of the drive assembly can provide shielding, it can further reduce electromagnetic interference. .

Optionally, the drive assembly provided in the embodiment of the present application may be applied to electric equipment such as a vehicle or a ship, and the application of the drive assembly to a vehicle is taken as an example. When the vehicle is in driving mode, the two-level inverter circuit in the drive assembly is used to convert DC power into AC power, and the drive motor converts electrical energy into mechanical energy. When the vehicle is in the charging mode, the switch tube in the two-level inverter circuit in the drive assembly can be used, and the motor coil in the drive assembly can be used as a boost inductor to realize boost charging through the above excitation process and charging process.

In an implementation manner, the first group of switch transistors includes a first switch transistor, and the second group of switch transistors includes a second switch transistor. The first end of the first switch tube is the first input end of the two-level inverter circuit, and the second end of the first switch tube is the second output end of the three-phase output ends of the two-level inverter circuit. The second end of the first switch tube is coupled to the first end of the second switch tube, and the second end of the first switch tube and the first end of the second switch tube are coupled to the second end of the motor coil through the first filter magnetic ring . The second terminal of the second switching tube is the second input terminal of the two-level inverter circuit; the third terminal of the first switching tube and the third terminal of the second switching tube are control terminals.

Based on this scheme, when the drive assembly is not used to drive electric equipment such as vehicles or ships, the two switch tubes in the drive assembly can be borrowed, and the motor coil in the drive assembly can be used as a boost inductor to convert the DC power The voltage is boosted and charges the battery pack. This solution borrows the switch tube in the drive assembly, and can use the motor coil and switch tube in the drive assembly to excite the motor coil and charge the battery pack when the drive assembly is not used for driving equipment such as vehicles. When the motor coil is excited and the battery pack is charged, the current direction of the current passing through the first filter magnetic ring twice is opposite. Therefore, the magnetic fluxes generated on the first filter magnetic ring can cancel each other out, and the first filter magnetic ring will not be saturated.

In an implementation manner, when the motor coil is excited, the first switch tube is in a conduction state, and the second switch tube is in an off state. When charging the battery pack, the first switching tube is in an off state, and the second switching tube is in a conducting state.

Optionally, the above-mentioned first switch tube and the second switch tube are N-type metal oxide semiconductor MOS tubes, the first end of the first switch tube is a drain, the second end of the first switch tube is a source, and the second end of the first switch tube is a source. The third terminal of the first switching tube is the grid, the first terminal of the second switching tube is the drain, the second terminal of the second switching tube is the source, and the third terminal of the second switching tube is the grid.

Based on this solution, when the drive assembly is not used to drive electric equipment such as vehicles or ships, the first switch tube and the second switch tube in the drive assembly can be borrowed, and by controlling the first switch tube and the second switch tube The on and off of the current can make the current pass through the first filter magnetic ring twice during the excitation process and the charging process, and the current direction of the current passing through the first filter magnetic ring twice is opposite. Therefore, on the first filter magnetic ring The generated magnetic fluxes can cancel each other, and the first filter magnetic ring will not be saturated, which can reduce electromagnetic interference, reduce the influence of EMC on the safe operation of the vehicle and the influence of magnetic ring saturation on filter performance.

In an implementation manner, the first group of switching transistors further includes a third switching transistor, and the second group of switching transistors further includes a fourth switching transistor. The first end of the third switch tube is the first input end of the two-level inverter circuit, and the second end of the third switch tube is the third output end of the three-phase output ends of the two-level inverter circuit. The second end of the third switch tube is coupled to the first end of the fourth switch tube, and the second end of the third switch tube and the first end of the fourth switch tube are coupled to the first end of the motor coil through the first filter magnetic ring. Three terminals, the second terminal of the fourth switching tube is the second input terminal of the two-level inverter circuit. The third terminal of the third switch tube and the third terminal of the fourth switch tube are control terminals.

Based on this scheme, when the drive assembly is not used to drive electric equipment such as vehicles or ships, the four switch tubes in the drive assembly can be borrowed, and the motor coil in the drive assembly can be used as a boost inductor to convert the DC power The voltage is boosted and charges the battery pack. This solution borrows the switch tube in the drive assembly, and can use the motor coil and switch tube in the drive assembly to excite the motor coil and charge the battery pack when the drive assembly is not used for driving equipment such as vehicles. When the motor coil is excited and the battery pack is charged, the current direction of the current passing through the first filter magnetic ring twice is opposite. Therefore, the magnetic fluxes generated on the first filter magnetic ring can cancel each other out, and the first filter magnetic ring will not be saturated.

In an implementation manner, when the motor coil is excited, the third switch tube is in the on state, and the fourth switch tube is in the off state. When charging the battery pack, the third switch tube is in the off state, and the fourth switch tube is in the on state.

Optionally, the third switch tube and the fourth switch tube are N-type MOS tubes, the first end of the third switch tube is a drain, the second end of the third switch tube is a source, and the first end of the third switch tube is a source. The three terminals are gates, the first terminal of the fourth switch tube is a drain, the second terminal of the fourth switch tube is a source, and the third terminal of the fourth switch tube is a grid.

Based on this solution, when the drive assembly is not used to drive electric equipment such as vehicles or ships, the first to fourth switch tubes in the drive assembly can be borrowed, and by controlling the first to fourth switch tubes The turn-on and turn-off of the motor coil can make the current flow through the first filter magnetic ring twice in each circuit when the motor coil is excited and the battery pack is charged, and the current direction of the current passing through the first filter magnetic ring twice On the contrary, therefore, the magnetic flux generated on the first filter magnetic ring can cancel each other, the first filter magnetic ring will not be saturated, can reduce electromagnetic interference, reduce the impact of EMC on the safe operation of the vehicle and the influence of magnetic ring saturation on the filter performance influences.

In one implementation, the above-mentioned drive assembly further includes a second filter magnetic ring, through which the first input end of the two-level inverter circuit is coupled to the positive pole of the battery pack, and the two-level inverter circuit The second input end is coupled to the negative pole of the battery pack through the second filtering magnetic ring. When the motor coil is excited, the current flows out from the positive pole of the DC power supply, passes through the first group of switch tubes in the two-level inverter circuit, the first filter magnetic ring, and the motor coil, and passes through the first filter magnetic ring again, and flows back to to the negative terminal of the DC power supply. When charging the battery pack, the current flows out from the positive pole of the DC power supply, and passes through the second filter magnetic ring, the battery pack, the second filter magnetic ring, the second group of switch tubes, the first filter magnetic ring, the motor coil, the first filter magnetic ring, and the first filter magnetic ring. After the magnetic ring, it flows back to the negative pole of the DC power supply.

Based on this scheme, when charging the battery pack, the current will pass through the first filter magnetic ring twice and the second filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time is different from that of the current second time. The direction of the current passing through the first filter magnetic ring is opposite, and the current direction of the current passing through the second filter magnetic ring for the first time is opposite to the current direction of the current passing through the second filter magnetic ring for the second time, so the magnetic flux generated on the first filter magnetic ring The flux can cancel each other, and the magnetic flux generated on the second filter magnetic ring can also cancel each other, so the first filter magnetic ring and the second filter magnetic ring will not be saturated, which can reduce electromagnetic interference and reduce the impact of EMC on the safe operation of the vehicle. The influence of and the influence of magnetic ring saturation on the filter performance.

In an implementation manner, when the drive assembly is not used for driving the vehicle, the drive assembly excites the motor coil and charges the battery pack.

Based on this solution, when the drive assembly is not used for driving the vehicle (for example, when the vehicle is in charging mode), the switch tube in the two-level inverter circuit in the drive assembly can be controlled, and the motor coil in the drive assembly can As a boost inductor, it excites the motor coil and charges the battery pack. It can be understood that when the drive assembly is used for driving a vehicle and when the drive assembly is not used for driving a vehicle, the functions of the two-level inverter circuit and the motor coil in the drive assembly are different. For example, when the drive assembly is used for vehicle driving, the two-level inverter circuit is used to convert DC power into AC power, and the drive motor converts electrical energy into mechanical energy. When the drive assembly is not used for vehicle driving, it just borrows the switch tube in the two-level inverter circuit, and uses the motor coil as a boost inductor to realize the boost charging function.

In a second aspect of the embodiments of the present application, a control method of a drive assembly is provided, and the drive assembly includes a two-level inverter circuit, a first filter magnetic ring, and a motor coil. The first input terminal and the second input terminal of the two-level inverter circuit are respectively used for coupling with the positive pole and the negative pole of the battery pack, and the first input terminal of the two-level inverter circuit is also used for coupling with the positive pole of the DC power supply connection; the three-phase output terminals of the two-level inverter circuit are respectively coupled to the three terminals of the motor coil through the first filter magnetic ring. The first output terminal of the three-phase output terminals of the two-level inverter circuit is used for coupling connection with the negative pole of the DC power supply before passing through the first filter magnetic ring. The two-level inverter circuit includes a first group of switching tubes and a second group of switching tubes, and the first group of switching tubes and the second group of switching tubes respectively include one or more switching tubes. The above method includes: when the motor coil is excited, the first group of switching tubes is controlled to be turned on, the second group of switching tubes is turned off, the current flows out from the positive pole of the DC power supply, and passes through the first group of switching tubes in the two-level inverter circuit , the first filter magnetic ring, the motor coil, and flow back to the negative pole of the DC power supply after passing through the first filter magnetic ring again. When charging the battery pack, the first set of switch tubes is controlled to be turned off, the second set of switch tubes is turned on, and the current flows out from the positive pole of the DC power supply, passing through the battery pack, the second set of switch tubes in the two-level inverter circuit, The first filter magnetic ring, the motor coil, and after passing through the first filter magnetic ring again, flow back to the negative pole of the DC power supply.

In an implementation manner, the above-mentioned first group of switching transistors includes a first switching transistor, and the second group of switching transistors includes a second switching transistor. The first end of the first switch tube is the first input end of the two-level inverter circuit, and the second end of the first switch tube is the second output end of the three-phase output ends of the two-level inverter circuit. The second end of the first switch tube is coupled to the first end of the second switch tube, and the second end of the first switch tube and the first end of the second switch tube are coupled to the second end of the motor coil through the first filter magnetic ring . The second end of the second switch tube is the second input end of the two-level inverter circuit, and the third end of the first switch tube and the third end of the second switch tube are control ends.

In an implementation manner, when the motor coil is excited, the first switch tube is in a conduction state, and the second switch tube is in an off state. When charging the battery pack, the first switching tube is in an off state, and the second switching tube is in a conducting state.

In one implementation, the first switch tube and the second switch tube are N-type metal oxide semiconductor MOS tubes, the first end of the first switch tube is a drain, the second end of the first switch tube is a source, and the second end of the first switch tube is a source. The third terminal of the first switching tube is the grid, the first terminal of the second switching tube is the drain, the second terminal of the second switching tube is the source, and the third terminal of the second switching tube is the grid.

In an implementation manner, the first group of switching transistors further includes a third switching transistor, and the second group of switching transistors further includes a fourth switching transistor. The first end of the third switching tube is the first input end of the two-level inverter circuit, and the second end of the third switching tube is the third output end of the three-phase output terminals of the two-level inverter circuit; the third The second end of the switch tube is coupled to the first end of the fourth switch tube, the second end of the third switch tube and the first end of the fourth switch tube are coupled to the third end of the motor coil through the first filter magnetic ring, and the second end of the switch tube is coupled to the third end of the motor coil. The second terminal of the four switching tubes is the second input terminal of the two-level inverter circuit; the third terminal of the third switching tube and the third terminal of the fourth switching tube are control terminals.

In one implementation, when the motor coil is excited, the third switch tube is in the on state, and the fourth switch tube is in the off state; when the battery pack is charged, the third switch tube is in the off state, and the fourth switch tube is in the off state. The tube is in conduction state.

In one implementation, the third switch tube and the fourth switch tube are N-type MOS tubes, the first end of the third switch tube is a drain, the second end of the third switch tube is a source, and the third switch tube The third end is the grid, the first end of the fourth switch tube is the drain, the second end of the fourth switch tube is the source, and the third end of the fourth switch tube is the grid.

In one implementation, the drive assembly further includes a second filter magnetic ring, through which the first input terminal of the two-level inverter circuit is coupled to the positive pole of the battery pack, and the first input terminal of the two-level inverter circuit is coupled to the positive pole of the battery pack. The two input ends are coupled to the negative pole of the battery pack through the second filtering magnetic ring. When the motor coil is excited, the current flows out from the positive pole of the DC power supply, passes through the first group of switch tubes in the two-level inverter circuit, the first filter magnetic ring, and the motor coil, and passes through the first filter magnetic ring again, and flows back to to the negative terminal of the DC power supply. When charging the battery pack, the current flows out from the positive pole of the DC power supply, and passes through the second filter magnetic ring, the battery pack, the second filter magnetic ring, the second group of switch tubes, the first filter magnetic ring, the motor coil, the first filter magnetic ring, and the first filter magnetic ring. After the magnetic ring, it flows back to the negative pole of the DC power supply.

In an implementation manner, when the drive assembly is not used for driving the vehicle, the drive assembly excites the motor coil and charges the battery pack.

For the description of the effects of the above-mentioned second aspect and various implementation manners of the second aspect, reference may be made to the description of the corresponding effects of the first aspect, and details are not repeated here.

The third aspect of the embodiments of the present application provides a charging system, the charging system includes a power distribution circuit, and the drive assembly as described in the first aspect above, the first input terminal of the two-level inverter circuit It is coupled and connected to the positive pole of the DC power supply through the power distribution circuit.

The fourth aspect of the embodiments of the present application provides an electric device, the electric device includes a power distribution circuit, and the drive assembly as described in the first aspect above, the first two-level inverter circuit The input end is coupled and connected to the positive pole of the DC power supply through the power distribution circuit.

In an implementation manner, the above electric device further includes a battery pack. Optionally, the electrical equipment may be electrical equipment such as a vehicle or a ship, and the drive assembly in the electrical equipment may excite the motor coil and charge the battery pack when not used for equipment driving.

Description of drawings

FIG. 1 is a schematic diagram of a circuit structure of a charging system provided by an embodiment of the present application;

Fig. 2 is a schematic diagram of the working principle of a charging system provided in the embodiment of the present application when exciting the motor coil;

Fig. 3 is a schematic diagram of the working principle of a charging system provided in an embodiment of the present application when charging a battery pack;

Fig. 4 is a schematic diagram of the magnetic flux generated when a unidirectional current passes through the magnetic ring provided by the embodiment of the present application;

FIG. 5 is a schematic structural diagram of a vehicle charging provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of a circuit structure of a drive assembly provided by an embodiment of the present application;

Fig. 7 is a schematic diagram of the working principle when exciting the motor coil in the drive assembly provided by the embodiment of the present application;

Fig. 8 is an equivalent circuit diagram when exciting the motor coil in the drive assembly provided by the embodiment of the present application;

Fig. 9 is a schematic diagram of the magnetic flux generated when a bidirectional current passes through the magnetic ring provided by the embodiment of the present application;

Fig. 10 is a schematic diagram of the working principle when charging the battery pack in the drive assembly provided by the embodiment of the present application;

Fig. 11 is an equivalent circuit diagram when charging the battery pack in the drive assembly provided by the embodiment of the present application;

Fig. 12 is another schematic diagram of the working principle when exciting the motor coil in the drive assembly provided by the embodiment of the present application;

Fig. 13 is another schematic diagram of the working principle when charging the battery pack in the drive assembly provided by the embodiment of the present application;

Fig. 14 is a schematic diagram of the circuit structure of another drive assembly provided by the embodiment of the present application;

Fig. 15 is another schematic diagram of the working principle when exciting the motor coil in the drive assembly provided by the embodiment of the present application;

Fig. 16 is another schematic diagram of the working principle when charging the battery pack in the drive assembly provided by the embodiment of the present application;

Fig. 17 is another schematic diagram of the working principle when exciting the motor coil in the drive assembly provided by the embodiment of the present application;

Fig. 18 is another schematic diagram of the working principle when charging the battery pack in the drive assembly provided by the embodiment of the present application;

Fig. 19 is a schematic structural diagram of an electrical device provided by an embodiment of the present application;

Fig. 20 is a schematic flowchart of a method for controlling a drive assembly provided by an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In this application, "at least one" means one or more, and "multiple" means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A, B can be singular or plural. The character "/" generally indicates that the contextual objects are an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one item (piece) of a, b or c can represent: a, b, c, a and b, a and c, b and c, or, a and b and c, wherein a, b and c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same function and effect, Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order. For example, "first" in the first filter magnetic ring and "second" in the second filter magnetic ring in the embodiment of the present application are only used to distinguish different filter magnetic rings. The first, second, etc. descriptions that appear in the embodiments of this application are only for illustration and to distinguish the description objects. Any limitations of the examples.

It should be noted that, in this application, words such as "exemplary" or "for example" are used as examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "for example" is not to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete manner.

At present, the charging piles used for charging electric vehicles on the market can be divided into high-voltage charging piles and low-voltage charging piles. The output voltage of high-voltage charging piles is generally 200V-750V, and the output voltage of low-voltage charging piles is generally 200V-500V.

In order to improve the battery life of electric vehicles, the battery system of electric vehicles can use a high-voltage battery system. However, most of the charging piles currently on the market are low-voltage charging piles, which can only charge low-voltage battery systems (for example, 450V) and cannot charge high-voltage battery systems (for example, 750V). In order to realize that the low-voltage charging pile can charge the high-voltage battery system, in the charging mode, the output voltage of the low-voltage charging pile can be adjusted by reusing the motor coil in the electric vehicle and the switching device in the two-level inverter circuit in the prior art. Boost the voltage so that the low-voltage charging pile can charge the high-voltage battery system, thereby realizing the boost charging function.

For example, FIG. 1 is a schematic diagram of a circuit structure of a charging system. As shown in Figure 1, the charging system may include a DC power supply, a power distribution circuit (for example, a power distribution box), a drive assembly, and a battery pack. The drive assembly includes an MCU filter magnetic ring, a two-level inverter circuit, a three-phase Nanocrystalline magnetic rings and motor coils. The DC power supply may be a DC power output from the charging pile.

As shown in Figure 1, in the driving mode, the switch K3 in the battery pack, the switches K4 and K5 in the power distribution circuit are all in the off state, and the switches K1 and K2 in the battery pack are in the on state. After the DC voltage of the battery pack is filtered by the MCU filter magnetic ring, by controlling the switch tubes M1 to M6 in the two-level inverter circuit, the DC power can be converted into AC power, and the motor coil is driven after being filtered by the three-phase nanocrystalline magnetic ring. Convert electrical energy into mechanical energy. In the charging mode, the DC power output by the charging pile passes through the power distribution circuit, and the motor coil in the drive assembly is used as a boost inductor to control the on and off of the switch tube in the two-level inverter circuit in the drive assembly. If it is disconnected, the low-voltage DC power output from the charging pile can be boosted to charge the high-voltage battery pack. When the charging system shown in Figure 1 implements boost charging, it can include the motor coil excitation process and the battery pack charging process. The excitation process and charging process of the charging system shown in Figure 1 are described below in conjunction with Figure 2 and Figure 3. for details.

Fig. 2 is a structural schematic diagram of a motor coil excitation process. As shown in Figure 2, when the motor coil in the drive assembly is excited, the switches K6 and K7 of the DC power supply, the switches K4 and K5 in the power distribution circuit, and the switch K3 in the battery pack are all in the conduction state, and control The switch tube M5 in the two-level inverter circuit is turned on. Therefore, the circuit of the motor coil excitation process is: the positive pole of the DC power supply → power distribution circuit → battery pack → MCU filter magnetic ring → switch tube M5 in the two-level inverter circuit → three-phase nanocrystalline magnetic ring → motor coil → distribution Electrical circuit → the negative pole of the DC power supply.

FIG. 3 is a schematic structural diagram of a battery pack charging process. As shown in Figure 3, when charging the battery pack, the switches K6 and K7 of the DC power supply, the switches K4 and K5 in the power distribution circuit, and the switches K1 to K3 in the battery pack are all in the conducting state, and control the two levels The switch tube M6 in the inverter circuit is turned on. Therefore, the circuit of the charging process of the battery pack is: the positive pole of the DC power supply → power distribution circuit → battery pack → MCU filter magnetic ring → switch tube M6 in the two-level inverter circuit → three-phase nanocrystalline magnetic ring → motor coil → distribution Electrical circuit → the negative pole of the DC power supply.

When the charging system shown in Figure 1 is boosted and charged, the excitation process shown in Figure 2 and the charging process shown in Figure 3 can be carried out alternately at a certain frequency, because after the excitation process excites the motor coil, energy can be stored in the motor coil , so that in the process of charging the battery pack, the voltage of the motor coil and the voltage of the DC power supply can be superimposed to charge the battery pack, and the low-voltage charging pile can be used to charge the high-voltage battery system.

It can be understood from FIG. 2 and FIG. 3 that in the charging system shown in FIG. 1 , the functions of the two-level inverter circuit and the motor coil in the drive assembly are different in the driving mode and the charging mode. In the driving mode, the two-level inverter circuit is used to convert DC power into AC power, and the drive motor converts electrical energy into mechanical energy. In the charging mode, only the switch tube in the two-level inverter circuit is used, and the motor coil is used as a boost inductor to realize the boost charging function. That is to say, when the low-voltage charging pile charges the high-voltage battery pack, the switch tube and motor coil in the drive assembly can be borrowed to realize the boost charging function.

Combining Figure 2 and Figure 3, it can be seen that when the motor coil is excited, the current flowing in the MCU filter magnetic ring and the three-phase nanocrystalline magnetic ring is unidirectional. When the battery pack is charging, the current flowing in the MCU filter magnetic ring and the three-phase nanocrystalline magnetic ring is also unidirectional. That is, when the motor coil is excited and the battery pack is charged, only one direction of current passes through the MCU filter magnetic ring and the three-phase nanocrystalline magnetic ring.

Figure 4 is a schematic diagram of the magnetic flux generated when a unidirectional current passes through the magnetic ring. The solid line with arrows in Figure 4 indicates the direction of the current passing through the magnetic ring, and the dotted line with arrows indicates the direction of the magnetic flux generated on the magnetic ring. As shown in Figure 4, when only one direction of current passes through the magnetic ring, the magnetic flux generated on the magnetic ring cannot cancel each other out, and the magnetic ring will be saturated. That is to say, when the charging system shown in Figure 1 excites the motor coil and charges the battery pack, since the current flowing through the MCU filter magnetic ring and the three-phase nanocrystalline magnetic ring in the drive assembly is unidirectional, Therefore, the MCU filter magnetic ring and the three-phase nanocrystalline magnetic ring will be saturated, and the saturation of the magnetic ring will not only affect the filtering effect, but also affect the EMC and safe operation of the vehicle.

Fig. 5 is a schematic diagram of a vehicle charging structure. Combining Fig. 2 and Fig. 3, as shown in Fig. 5, when the low-voltage charging pile is charging the high-voltage battery pack, part of the circuit in the excitation process and charging process is outside the drive assembly. As a result, the loop area of the excitation process and the charging process is large, and there is a serious electromagnetic interference problem on the vehicle, which affects the achievement of the EMC index of the vehicle and the electromagnetic safety in actual operation.

In order to solve the problem that the electromagnetic interference of the charging system is relatively large due to the saturation of the magnetic ring during the charging process of the low-voltage charging pile to the high-voltage battery system, which affects the EMC and the safe operation of the vehicle, the embodiment of the present application provides a drive assembly. When the boost charging function is realized, the direction of the current flowing on the filter magnetic ring is bidirectional, the magnetic flux generated on the filter magnetic ring can cancel each other, and the filter magnetic ring will not be saturated, so it can reduce electromagnetic interference and reduce EMC The impact on the safe operation of the vehicle, and the impact of the saturation of the magnetic ring on the filter performance. Moreover, the present application integrates the circuits of the excitation process and the charging process inside the drive assembly, since the metal shell of the drive assembly can provide shielding effect, so the electromagnetic interference can be further reduced.

An embodiment of the present application provides a drive assembly, and the drive assembly may be a drive assembly in electrical equipment such as a vehicle or a ship. The drive assembly can be used to drive electrical equipment such as vehicles or boats, or when the drive assembly is not used to drive electrical equipment such as vehicles or boats (for example, when charging electrical equipment such as vehicles or boats), the motor coil Excite and charge the battery pack. For example, when the vehicle is in driving mode, the drive assembly is used to drive the vehicle; when the vehicle is in charging mode, the drive assembly is used to excite the motor coil and charge the battery pack.

As shown in FIG. 6 , the drive assembly provided by the embodiment of the present application includes a two-level inverter circuit, a first filter magnetic ring, and a motor coil. The first input terminal a and the second input terminal b of the two-level inverter circuit are respectively used for coupling and connection with the positive pole and the negative pole of the battery pack, and the first input terminal a of the two-level inverter circuit is also used for coupling with the DC power supply positive coupling connection. The three-phase output terminals (c-terminal, d-terminal and e-terminal) of the two-level inverter circuit are respectively coupled to the three terminals (f-terminal, g-terminal and h-terminal) of the motor coil through the first filter magnetic ring. The first output end c of the three-phase output ends of the two-level inverter circuit is used for coupling connection with the negative pole of the DC power supply before passing through the first filter magnetic ring.

For example, as shown in Figure 6, the first input terminal a of the two-level inverter circuit is used for coupling with the positive pole of the battery pack, and the second input terminal b of the two-level inverter circuit is used for coupling with the negative pole of the battery pack. The first input terminal a of the two-level inverter circuit is also used for coupling and connection with the positive pole of the DC power supply. The first output end c of the three-phase output ends of the two-level inverter circuit is coupled to the first end d of the motor coil through the first filter magnetic ring, and the second end of the three-phase output ends of the two-level inverter circuit is The output terminal e is coupled to the second terminal f of the motor coil through the first filter magnetic ring, and the third output terminal g of the three-phase output terminals of the two-level inverter circuit is coupled to the motor coil through the first filter magnetic ring. The third end h. Before the first output end c of the three-phase output ends of the two-level inverter circuit passes through the first filter magnetic ring, the first output end c is used for coupling connection with the positive pole of the DC power supply. The DC power shown in Figure 6 can be the DC power output by the charging pile.

Optionally, the first filter magnetic ring may be a three-phase nanocrystalline magnetic ring, and the embodiment of the present application does not limit the specific type of the first filter magnetic ring. In the embodiment of the present application, when the three-phase output terminals of the two-level inverter circuit are respectively coupled to the three terminals of the motor coil through the first filter magnetic ring, the three-phase output terminals of the two-level inverter circuit are connected from the first filter magnetic ring After passing through the center, they are respectively coupled to the three ends of the motor coil.

The two-level inverter circuit includes a first group of switching tubes and a second group of switching tubes. The first group of switch transistors may include one or more switch transistors, and the second group of switch transistors may also include one or more switch transistors. The number of switching transistors included in the first group of switching transistors is the same as the number of switching transistors included in the second group of switching transistors.

When the motor coil is excited, the current flows out from the positive pole of the DC power supply, passes through the first group of switch tubes, the first filter magnetic ring, and the motor coil in the two-level inverter circuit, and passes through the first filter magnetic ring again. Return to the negative terminal of the DC power supply. That is, when the motor coil is excited, the current passes through the first filtering magnetic ring twice.

When charging the battery pack, the current flows out from the positive pole of the DC power supply, passes through the battery pack, the second set of switch tubes in the two-level inverter circuit, the first filter magnetic ring, and the motor coil, and then passes through the first filter magnetic After the loop, it flows back to the negative terminal of the DC power supply. That is, when charging the battery pack, the current passes through the first filter magnetic ring twice.

Optionally, the first group of switching transistors includes a first switching transistor, and the second group of switching transistors includes a second switching transistor. The first end of the first switch tube is the first input end of the two-level inverter circuit, and the second end of the first switch tube is the second output end of the three-phase output ends of the two-level inverter circuit. The second end of the first switch tube is coupled to the first end of the second switch tube, and the second end of the first switch tube and the first end of the second switch tube are coupled to the second end of the motor coil through the first filter magnetic ring , the second end of the second switching tube is the second input end of the two-level inverter circuit. The third terminal of the first switch tube and the third terminal of the second switch tube are control terminals.

Optionally, the above-mentioned first switching tube and the second switching tube may be metal-oxide-semiconductor field-effect transistors (MOSFET, referred to as MOS transistors), or insulated gate bipolar transistors. A transistor (insulated gate bipolar transistor, IGBT), which is not limited in this embodiment of the present application. When the first switch tube and the second switch tube are MOS tubes, they may be N-type MOS tubes or P-type MOS tubes. The first end of the first switch tube is the drain, the second end of the first switch tube is the source, the third end of the first switch tube is the grid, the first end of the second switch tube is the drain, and the second end of the second switch tube is the drain. The second end of the switch tube is the source, and the third end of the second switch tube is the gate.

For example, taking the first group of switching tubes and the second group of switching tubes respectively including one switching tube as an example, as shown in FIG. 6, the first group of switching tubes includes the first switching tube M1, and the second group of switching tubes includes the second switching tube M2. The drain of the first switching tube M1 is the first input terminal a of the two-level inverter circuit, and the source of the first switching tube M1 is the second output terminal e of the three-phase output terminals of the two-level inverter circuit. The source of the first switching tube M1 is coupled to the drain of the second switching tube M2, and the source of the first switching tube M1 and the drain of the second switching tube M2 are coupled to the second end of the motor coil through the first filter magnetic ring f, the source of the second switching tube M2 is the second input terminal b of the two-level inverter circuit. The gate of the first switch M1 and the gate of the second switch M2 are control terminals.

When the motor coil is excited, the first switch tube is in a conduction state, and the second switch tube is in an off state. When charging the battery pack, the first switching tube is in an off state, and the second switching tube is in a conducting state.

In the following, the first group of switching tubes and the second group of switching tubes respectively include a switching tube, the first group of switching tubes includes the first switching tube M1, and the second group of switching tubes includes the second switching tube M2 as an example, referring to FIG. 7 to FIG. 10 Introduce the excitation process and charging process when the drive assembly shown in Figure 6 realizes boost charging.

Combined with Figure 6, as shown in Figure 7, when the motor coil is excited, the first switching tube M1 is controlled to be turned on, and the second switching tube M2 is turned off. After the current flows out from the positive pole of the DC power supply, it passes through the two-level inverter circuit The first switching tube M1 in the circuit, after passing through the first filter magnetic ring, flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the DC power supply through the first filter magnetic ring The negative pole forms a loop. That is, the circuit of the motor coil excitation process is: the positive pole of the DC power supply → the first switching tube M1 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

FIG. 8 is an equivalent circuit diagram of the excitation process of the above-mentioned motor coil. The motor coil in FIG. 7 can be equivalent to an inductor L, and the first switching tube M1 in FIG. 7 can be equivalent to a switching tube Q. Combined with FIG. 7, as shown in FIG. 8, the DC power supply V _in forms a closed loop through the inductor L and the switch tube Q, and the DC power supply V _{in excites} the motor coil. During excitation, the motor coil acts as a boost inductor to store energy.

According to the above Figure 7, it can be seen that when the motor coil is excited, the current will pass through the first filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time is the same as that of the current passing through the first filter magnetic ring for the second time. The current flows in the opposite direction. The current direction of the current passing through the first filter magnetic ring for the first time is from the first group of switch tubes to flow into the first filter magnetic ring, and the current direction of the current passing through the first filter magnetic ring for the second time is to flow out of the first filter magnetic ring.

For example, as shown in FIG. 9 , the solid line with arrows in FIG. 9 indicates the direction of current passing through the first filter magnetic ring, and the dotted line with arrows indicates the direction of magnetic flux generated on the first filter magnetic ring. In Figure 9, the current direction when the current passes through the first filter magnetic ring for the first time is to flow into the first filter magnetic ring, and the current direction when the current passes through the first filter magnetic ring for the second time is to flow out of the first filter magnetic ring. The direction of the current passing through the first filter magnetic ring is opposite, so the magnetic flux generated on the first filter magnetic ring can cancel each other, and the first filter magnetic ring will not be saturated, which can reduce electromagnetic interference and reduce the impact of EMC on the safe operation of the vehicle. Influence, and the influence of magnetic ring saturation on filter performance.

Combined with Figure 6, as shown in Figure 10, when charging the battery pack, control the second switch tube M2 to turn on, and the first switch tube M1 to turn off, after the current flows out from the positive pole of the DC power supply, it passes through the battery pack and the two levels The second switching tube M2 in the inverter circuit flows in from the second end f of the motor coil through the first filter magnetic ring, flows out from the first end d of the motor coil, and then flows back to DC through the first filter magnetic ring The negative pole of the power supply forms a loop. That is, the circuit of the charging process of the battery pack is: the positive pole of the DC power supply → the battery pack → the second switch tube M2 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

FIG. 11 is an equivalent circuit diagram of the above battery pack charging process. The motor coil in FIG. 10 can be equivalent to an inductor L, and the second switching tube M2 in FIG. 10 can be equivalent to a switching tube D. Combined with Figure 10, as shown in Figure 11, the DC power supply V _in and the inductor L form a closed loop through the switch tube D, the DC power supply _Vin and the inductor L jointly charge the battery pack, and the charging voltage of the battery pack Vout=Vin+Ldi/dt , where Ldi/dt is the voltage across the inductor. For example, taking the switching frequency of the switching tube as about 10kHz and the input DC power supply voltage as about 450V as an example, the excitation process shown in Figure 7 and the charging process shown in Figure 10 are carried out alternately at a frequency of 10kHz, and the DC power supply can be The voltage of 450V is boosted to about 750V, so that the low-voltage DC power supply can charge the high-voltage battery system.

According to the above Figure 10, it can be seen that when the motor coil is charged, the current will pass through the first filter magnetic ring twice, and the direction of the current passing through the first filter magnetic ring for the first time is the same as the direction of the current passing through the first filter magnetic ring for the second time. on the contrary. Combining with the above figure 9, it can be seen that since the current direction of the current passing through the first filter magnetic ring twice is opposite, the magnetic flux generated on the first filter magnetic ring can cancel each other, the first filter magnetic ring will not be saturated, and the electromagnetic flux can be reduced. Interference, reduce the impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance.

7 and 10, it can be seen that when the drive assembly provided by the embodiment of the present application excites the motor coil and charges the battery pack, the direction of the current flowing through the first filter magnetic ring is bidirectional, so the first filter magnetic ring The generated magnetic fluxes can cancel each other out, and the first filter magnetic ring will not be saturated, so electromagnetic interference can be reduced, and the influence of EMC on the safe operation of the vehicle and the influence of magnetic ring saturation on filter performance can be reduced. Moreover, since the loops of the excitation process and the charging process of the present application are integrated inside the drive assembly, the metal shell of the drive assembly can provide shielding, so electromagnetic interference can be further reduced.

Optionally, the first group of switching transistors may further include a third switching transistor in addition to the first switching transistor, and the second group of switching transistors may further include a fourth switching transistor in addition to the second switching transistor. The first end of the third switch tube is the first input end of the two-level inverter circuit, and the second end of the third switch tube is the third output end of the three-phase output ends of the two-level inverter circuit. The second end of the third switch tube is coupled to the first end of the fourth switch tube, and the second end of the third switch tube and the first end of the fourth switch tube are coupled to the third end of the motor coil through the first filter magnetic ring , the second terminal of the third switching tube is the second input terminal of the two-level inverter circuit. The third terminal of the third switch tube and the third terminal of the fourth switch tube are control terminals.

Optionally, the above-mentioned third switch transistor and fourth switch transistor may be MOS transistors, or may be insulated gate bipolar transistors (IGBTs), which are not limited in this embodiment of the present application. When the third switch tube and the fourth switch tube are MOS tubes, they may be N-type MOS tubes or P-type MOS tubes. The first end of the third switch tube is the drain, the second end of the third switch tube is the source, the third end of the third switch tube is the gate, the first end of the fourth switch tube is the drain, and the fourth switch tube is the drain. The second end of the switch tube is the source, and the third end of the fourth switch tube is the gate.

For example, taking the first group of switching tubes and the second group of switching tubes respectively including two switching tubes as an example, as shown in Figure 6, the first group of switching tubes includes the first switching tube M1 and the third switching tube M3, and the second group The switch tubes include a second switch tube M2 and a fourth switch tube M4. The drain of M1 and the drain of M3 are the first input end a of the two-level inverter circuit, the source of M1 is the second output end e of the three-phase output end of the two-level inverter circuit, and the source of M3 is two The third output terminal g of the three-phase output terminals of the level inverter circuit. The source of M1 is coupled to the drain of M2, and the source of M1 and the drain of M2 are coupled to the second terminal f of the motor coil through the first filter magnetic ring. The source of M3 is coupled to the drain of M4, and the source of M3 and the drain of M4 are coupled to the third terminal h of the motor coil through the first filter magnetic ring. The source of M2 and the source of M4 are the second input terminal b of the two-level inverter circuit.

When the motor coil is excited, the first switch tube and the third switch tube are in a conduction state, and the second switch tube and the fourth switch tube are in an off state. When charging the battery pack, the first switch tube and the third switch tube are in the off state, and the second switch tube and the fourth switch tube are in the on state.

Below, the first group of switching tubes and the second group of switching tubes respectively include two switching tubes, the first group of switching tubes includes the first switching tube M1 and the third switching tube M3, and the second group of switching tubes includes the second switching tube M2 and the second switching tube. Taking the fourth switching tube M4 as an example, the excitation process and charging process of the drive assembly shown in FIG. 6 to realize boost charging are introduced with reference to FIGS. 12 and 13 .

In combination with FIG. 6, as shown in FIG. 12, when the motor coil is excited, the first switching tube M1 and the third switching tube M3 are controlled to be turned on, and the second switching tube M2 and the fourth switching tube M4 are turned off, as shown in FIG. 12 The circuit structure includes two loops. In one circuit, after the current flows out from the positive pole of the DC power supply, it passes through the first switch tube M1 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the second end f of the motor coil, and flows from the motor coil The first end d flows out, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. That is, a loop of the motor coil excitation process is: the positive pole of the DC power supply → the first switching tube M1 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply. In another loop, after the current flows out from the positive pole of the DC power supply, it passes through the third switching tube M3 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the third end h of the motor coil, and flows from the motor The first end d of the coil flows out, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. That is, another circuit in the excitation process of the motor coil is: the positive pole of the DC power supply → the third switching tube M3 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

According to the above figure 12, when the motor coil is excited, the current of the two loops will pass through the first filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time in each loop is the same as that of the current second The direction of the current passing through the first filter magnetic ring is opposite. Combining with the above figure 9, it can be seen that since in each loop, the direction of the current passing through the first filter magnetic ring twice is opposite, the magnetic flux generated on the first filter magnetic ring can cancel each other out, and the first filter magnetic ring will not be saturated , can reduce electromagnetic interference, reduce the impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance.

Referring to FIG. 6, as shown in FIG. 13, when charging the battery pack, the second switch M2 and the fourth switch M4 are controlled to be turned on, and the first switch M1 and the third switch M3 are turned off. The circuit shown in FIG. 13 The structure includes two loops. In one circuit, after the current flows out from the positive pole of the DC power supply, it passes through the battery pack and the second switch tube M2 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the second end f of the motor coil, and flows from The first end d of the motor coil flows out, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. That is, a circuit of the charging process of the battery pack is: the positive pole of the DC power supply → the battery pack → the second switch tube M2 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply. In another circuit, after the current flows out from the positive pole of the DC power supply, it passes through the battery pack and the fourth switching tube M4 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the third terminal h of the motor coil, and It flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. That is, another circuit in the charging process of the battery pack is: the positive pole of the DC power supply → the battery pack → the fourth switch tube M4 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

Combining with Figure 13, it can be seen that when the motor coil is charged, the current in each of the two loops will pass through the first filter magnetic ring twice, and the current direction of the first time through the first filter magnetic ring is the same as the second time through the first filter magnetic ring. The current direction of a filter magnetic ring is opposite. Combining with the above figure 9, it can be seen that in each loop, since the direction of the current passing through the first filter magnetic ring twice is opposite, the magnetic flux generated on the first filter magnetic ring can cancel each other out, and the first filter magnetic ring will not be saturated. , can reduce electromagnetic interference, reduce the impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance.

Optionally, as shown in Figure 14, the above-mentioned drive assembly may also include a second filter magnetic ring, the first input terminal of the two-level inverter circuit is coupled to the positive pole of the battery pack through the second filter magnetic ring, and the two-level The second input end of the inverter circuit is coupled to the negative pole of the battery pack through the second filter magnetic ring.

When the motor coil is excited, the current flows out from the positive pole of the DC power supply, passes through the first group of switch tubes in the two-level inverter circuit, the first filter magnetic ring, and the motor coil, and passes through the first filter magnetic ring again, and flows back to to the negative terminal of the DC power supply.

When charging the battery pack, the current flows out from the positive pole of the DC power supply, and passes through the second filter magnetic ring, the battery pack, the second filter magnetic ring, the second group of switch tubes, the first filter magnetic ring, the motor coil, the first filter magnetic ring, and the first filter magnetic ring. After the magnetic ring, it flows back to the negative pole of the DC power supply.

Optionally, the second filter magnetic ring may be an MCU filter magnetic ring. In the embodiment of the present application, when the first input terminal and the second input terminal of the two-level inverter circuit are respectively coupled to the positive pole and the negative pole of the battery pack through the second filter magnetic ring, the first input terminal and the second input terminal of the two-level inverter circuit The second input end may pass through the center of the second filter magnetic ring and be respectively coupled to the positive pole and the negative pole of the battery pack.

In the following, the first group of switching tubes and the second group of switching tubes respectively include a switching tube, the first group of switching tubes includes the first switching tube M1, and the second group of switching tubes includes the second switching tube M2 as an example, in combination with FIG. 15 and FIG. 16 Introduce the excitation process and charging process when the drive assembly shown in Figure 14 realizes boost charging.

Combined with Figure 14, as shown in Figure 15, when the motor coil is excited, the first switching tube M1 is controlled to be turned on, and the second switching tube M2 is turned off. After the current flows out from the positive pole of the DC power supply, it passes through the two-level inverter circuit The first switching tube M1 in the circuit, after passing through the first filter magnetic ring, flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the DC power supply through the first filter magnetic ring The negative pole forms a loop. That is, the circuit of the motor coil excitation process is: the positive pole of the DC power supply → the first switching tube M1 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

According to Figure 15, it can be seen that when the motor coil is excited, the current will pass through the first filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time is the same as that of the current passing through the first filter magnetic ring for the second time in the opposite direction. Combining with the above figure 9, it can be seen that since the current direction of the current passing through the first filter magnetic ring twice is opposite, the magnetic flux generated on the first filter magnetic ring can cancel each other, the first filter magnetic ring will not be saturated, and the electromagnetic flux can be reduced. Interference, reduce the impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance.

Referring to Figure 14, as shown in Figure 16, when charging the battery pack, control the second switching tube M2 to turn on, and the first switching tube M1 to turn off, after the current flows out from the positive pole of the DC power supply, it passes through the second filter magnetic ring, The battery pack flows into the second switching tube M2 in the two-level inverter circuit after passing through the second filter magnetic ring again, and then flows into the second end f of the motor coil through the first filter magnetic ring, and flows from the second end f of the motor coil The first end d flows out, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. That is, the circuit of the battery pack charging process is: the positive pole of the DC power supply → the second filter magnetic ring → the battery pack → the second filter magnetic ring → the second switch tube M2 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → The negative terminal of the DC power supply.

According to Figure 16, it can be seen that when charging the battery pack, the current will pass through the first filter magnetic ring twice and the second filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time is the same as that of the current second The current direction of the current passing through the first filter magnetic ring for the first time is opposite, and the current direction of the current passing through the second filter magnetic ring for the first time is opposite to the current direction of the current passing through the second filter magnetic ring for the second time, so the current generated on the first filter magnetic ring The magnetic flux can cancel each other, and the magnetic flux generated on the second filter magnetic ring can also cancel each other, so the first filter magnetic ring and the second filter magnetic ring will not be saturated, which can reduce electromagnetic interference and reduce EMC to vehicle safety The effect of operation, and the effect of magnetic ring saturation on filter performance.

Below, the first group of switching tubes and the second group of switching tubes respectively include two switching tubes, the first group of switching tubes includes the first switching tube M1 and the third switching tube M3, and the second group of switching tubes includes the second switching tube M2 and the second switching tube. Taking the fourth switching tube M4 as an example, the excitation process and charging process of the drive assembly shown in FIG. 14 to realize boost charging are introduced with reference to FIGS. 17 and 18 .

Referring to Fig. 14, as shown in Fig. 17, when the motor coil is excited, the first switching tube M1 and the third switching tube M3 are controlled to be turned on, and the second switching tube M2 and the fourth switching tube M4 are turned off, as shown in Fig. 17 The circuit structure includes two loops. In one circuit, after the current flows out from the positive pole of the DC power supply, it passes through the first switch tube M1 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the second end f of the motor coil, and flows from the motor coil The first end d flows out, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. That is, a loop of the motor coil excitation process is: the positive pole of the DC power supply → the first switch tube M1 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply. In another circuit, after the current flows out from the positive pole of the DC power supply, it passes through the third switching tube M3 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the third terminal h of the motor coil, and flows from the motor The first end d of the coil flows out, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. That is, another circuit in the excitation process of the motor coil is: the positive pole of the DC power supply → the third switching tube M3 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → the negative pole of the DC power supply.

According to Figure 17, when the motor coil is excited, in the two loops, the current in each loop will pass through the first filter magnetic ring twice, and the current in each loop passes through the first filter magnetic ring for the first time. The direction of the current passing through the first filtering magnetic ring for the second time is opposite to that of the current. Therefore, the magnetic flux generated on the first filter magnetic ring can cancel each other, and the first filter magnetic ring will not be saturated, which can reduce electromagnetic interference, reduce the influence of EMC on the safe operation of the vehicle, and the influence of magnetic ring saturation on filter performance.

Referring to FIG. 14, as shown in FIG. 18, when charging the battery pack, control the second switch M2 and the fourth switch M4 to turn on, and the first switch M1 and the third switch M3 to turn off, the circuit shown in FIG. 18 The structure includes two loops. In one circuit, after the current flows out from the positive pole of the DC power supply, it passes through the second filter magnetic ring, the battery pack, and flows into the second switch tube M2 in the two-level inverter circuit after passing through the second filter magnetic ring again, and then passes through the second filter magnetic ring. A filter magnetic ring flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. That is, a circuit in the charging process of the battery pack is: positive pole of the DC power supply → second filter magnetic ring → battery pack → second filter magnetic ring → second switch tube M2 → first filter magnetic ring → motor coil → first filter magnetic ring → Negative pole of DC power supply. In the other loop, after the current flows out from the positive pole of the DC power supply, it passes through the second filter magnetic ring, the battery pack, and flows into the fourth switch tube M4 in the two-level inverter circuit after passing through the second filter magnetic ring again, and then passes through The first filter magnetic ring flows in from the third end h of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. That is, a circuit of the charging process of the battery pack is: the positive pole of the DC power supply → the second filter magnetic ring → the battery pack → the second filter magnetic ring → the fourth switch tube M4 → the first filter magnetic ring → the motor coil → the first filter magnetic ring → Negative pole of DC power supply.

According to Figure 18, it can be seen that when charging the battery pack, the current will pass through the first filter magnetic ring twice and the second filter magnetic ring twice, and the current direction of the current passing through the first filter magnetic ring for the first time is the same as that of the current second The current direction of the current passing through the first filter magnetic ring for the first time is opposite, and the current direction of the current passing through the second filter magnetic ring for the first time is opposite to the current direction of the current passing through the second filter magnetic ring for the second time, so the current generated on the first filter magnetic ring The magnetic flux can cancel each other, and the magnetic flux generated on the second filter magnetic ring can also cancel each other. Therefore, neither the first filter magnetic ring nor the second filter magnetic ring will be saturated, which can further reduce electromagnetic interference and reduce EMC impact. The impact of vehicle safety operation, and the impact of magnetic ring saturation on filter performance.

The embodiment of the present application also provides a charging system, which includes a power distribution circuit, and a drive assembly as shown in any of the above-mentioned Figures 6, 7, 10, and 12-18. The first input terminal of the two-level inverter circuit is coupled and connected to the positive pole of the DC power supply through the power distribution circuit.

The embodiment of the present application also provides an electric device, the electric device includes a power distribution circuit, and a drive assembly as shown in any of the above-mentioned Figures 6, 7, 10, 12-18, the drive assembly The first input terminal of the formed two-level inverter circuit is coupled and connected to the positive pole of the DC power supply through the power distribution circuit. Optionally, the electric device may also include a battery pack.

Optionally, the electrical equipment may be equipment such as a vehicle or a ship, and the drive assembly may be a drive assembly in the electrical equipment such as a vehicle or a ship. The embodiment of the present application does not limit the specific type of electrical equipment. Any electrical equipment including the above-mentioned drive assembly is within the protection scope of the embodiment of the application. The electrical equipment can be used when the drive assembly is not used to drive the equipment. , to boost the low-voltage DC power supply and charge the battery pack in the device.

For example, as shown in FIG. 19 , taking the electric vehicle as an example, when the electric vehicle is in driving mode, the drive assembly can be used to drive the vehicle. When the electric vehicle is in the charging mode, the drive assembly is used to excite the motor coil in the electric vehicle and charge the battery pack. When the drive assembly is not used to drive the vehicle, after the DC power output from the charging pile passes through the power distribution circuit, the motor coil in the drive assembly can be used as a boost inductor to control the two-level inverter circuit in the drive assembly. The switch is turned on and off, which can boost the low-voltage DC power output from the charging pile to charge the high-voltage battery pack.

It can be known from Fig. 19 that, in the electrical equipment provided by the embodiment of the present application, since the direction of the current flowing through the filter magnetic ring in the drive assembly during the excitation process and the charging process is bidirectional, the magnetic flux generated on the filter magnetic ring can interact with each other. Offset, the filter magnetic ring will not be saturated, so it can reduce electromagnetic interference, reduce the impact of EMC on the safe operation of the vehicle, and the impact of magnetic ring saturation on filter performance. Moreover, because the application can integrate the circuits of the excitation process and the charging process inside the drive assembly, and since the metal shell of the drive assembly can provide shielding, electromagnetic interference can be further reduced.

The embodiment of the present application also provides a method for controlling a drive assembly, which may be the drive assembly shown in FIG. 6 or FIG. 14 . As shown in FIG. 20 , the method includes steps S2001-S2002.

S2001. When exciting the motor coil, control the first group of switch tubes to be turned on, and the second group of switch tubes to be turned off. The current flows from the positive pole of the DC power supply and passes through the first group of switch tubes and the second group of switch tubes in the two-level inverter circuit. A filter magnetic ring, the motor coil, and after passing through the first filter magnetic ring again, the flow returns to the negative pole of the DC power supply.

Exemplarily, taking the first group of switching tubes and the second group of switching tubes both including a switching tube, the first group of switching tubes includes the first switching tube, and the second group of switching tubes includes the second switching tube as an example, then in step S2001 Controlling the first group of switch tubes to be turned on and the second group of switch tubes to be turned off includes: controlling the first switch tubes to be turned on and controlling the second switch tubes to be turned off.

For example, if the drive assembly is the drive assembly shown in Figure 6 or Figure 14, the first switch tube is M1, and the second switch tube is M2 as an example, when the motor coil is excited, the first switch tube M1 is controlled to conduct, Control the second switching tube to turn off M2, as shown in Figure 7 or Figure 15, after the current flows out from the positive pole of the DC power supply, it passes through the first switching tube M1 in the two-level inverter circuit, and then passes through the first filter magnetic ring , flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop.

Exemplarily, the first group of switching tubes and the second group of switching tubes each include two switching tubes, the first group of switching tubes includes the first switching tube and the third switching tube, and the second group of switching tubes includes the second switching tube and Taking the fourth switching tube as an example, then in step S2001, controlling the first group of switching tubes to be turned on and the second group of switching tubes to be turned off includes: controlling the first switching tube and the third switching tube to be turned on, and controlling the second switching tube and the second switching tube to be turned on. The four switch tubes are turned off.

For example, if the drive assembly is the drive assembly shown in FIG. 6 or FIG. Take the switching tube M4 as an example. When the motor coil is excited, the first switching tube M1 and the third switching tube M3 are controlled to be turned on, and the second switching tube M2 and the fourth switching tube M4 are controlled to be turned off. As shown in Figure 12 or Figure 17, after the current of a loop flows out from the positive pole of the DC power supply, it passes through the first switching tube M1 in the two-level inverter circuit, passes through the first filter magnetic ring, and flows from the second Terminal f flows in, flows out from the first terminal d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. The current of the other loop flows out from the positive pole of the DC power supply, passes through the third switching tube M3 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the third end h of the motor coil, and flows from the motor coil The first end d flows out, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop.

S2002. When charging the battery pack, control the first group of switch tubes to be turned off, and the second group of switch tubes to be turned on. The current flows out from the positive pole of the DC power supply and passes through the battery pack and the second group of switches in the two-level inverter circuit Tube, first filter magnetic ring, motor coil, and after passing through the first filter magnetic ring again, it flows back to the negative pole of the DC power supply.

Exemplarily, taking the first group of switching tubes and the second group of switching tubes both including a switching tube, the first group of switching tubes includes the first switching tube, and the second group of switching tubes includes the second switching tube as an example, then in step S2002 Controlling the first group of switch tubes to be turned off and the second group of switch tubes to be turned on includes: controlling the first switch tube to be turned off and controlling the second switch tube to be turned on.

For example, if the drive assembly is the drive assembly shown in Figure 6, the first switch tube is M1, and the second switch tube is M2, when charging the battery pack, the first switch tube M1 is controlled to be turned off, and the second The switch tube is turned on for M2. As shown in Figure 10, after the current flows out from the positive pole of the DC power supply, it passes through the battery pack and the second switch tube M2 in the two-level inverter circuit, passes through the first filter magnetic ring, and flows in from the second end f of the motor coil. And flow out from the first end d of the motor coil, and then flow back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop.

For another example, take the drive assembly shown in Figure 14 as an example, the first switch tube is M1, and the second switch tube is M2. When charging the battery pack, control the first switch tube M1 to turn off, and control the second switch tube to turn off. The second switch tube is turned on for M2. As shown in Figure 16, after the current flows out from the positive pole of the DC power supply, it passes through the second filter magnetic ring, the battery pack, and flows into the second switch tube M2 in the two-level inverter circuit after passing through the second filter magnetic ring again, and then Through the first filter magnetic ring, it flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop.

Exemplarily, the first group of switching tubes and the second group of switching tubes each include two switching tubes, the first group of switching tubes includes the first switching tube and the third switching tube, and the second group of switching tubes includes the second switching tube and Taking the fourth switching tube as an example, then in step S2002, controlling the first group of switching tubes to be turned off and the second group of switching tubes to be turned on includes: controlling the first switching tube and the third switching tube to be turned off, and controlling the second switching tube and the second switching tube to be turned off. The four switch tubes are turned on.

For example, taking the drive assembly as the drive assembly shown in FIG. 6, the first group of switching tubes includes the first switching tube M1 and the third switching tube M3, and the second group of switching tubes includes the second switching tube M2 and the fourth switching tube M4. as an example. When charging the battery pack, the second switch M2 and the fourth switch M4 are controlled to be turned on, and the first switch M1 and the third switch M3 are turned off. As shown in Figure 13, the current of a loop flows out from the positive pole of the DC power supply, passes through the battery pack and the second switch tube M2 in the two-level inverter circuit, passes through the first filter magnetic ring, and flows from the second end of the motor coil f flows in and flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop. The current of the other loop flows out from the positive pole of the DC power supply, passes through the battery pack and the fourth switching tube M4 in the two-level inverter circuit, passes through the first filter magnetic ring, flows in from the third terminal h of the motor coil, and flows from The first end d of the motor coil flows out, and then flows back to the negative pole of the DC power supply through the first filtering magnetic ring again to form a loop.

For another example, take the drive assembly as shown in Figure 14, the first group of switch tubes includes the first switch tube M1 and the third switch tube M3, and the second set of switch tubes includes the second switch tube M2 and the fourth switch tube Take M4 as an example. When charging the battery pack, the second switch M2 and the fourth switch M4 are controlled to be turned on, and the first switch M1 and the third switch M3 are turned off. As shown in Figure 18, the current of one loop flows out from the positive pole of the DC power supply, passes through the second filter magnetic ring, the battery pack, and flows into the second switch tube in the two-level inverter circuit after passing through the second filter magnetic ring again M2 then passes through the first filter magnetic ring, flows in from the second end f of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop. The current of the other loop flows out from the positive pole of the DC power supply, passes through the second filter magnetic ring, the battery pack, and flows into the fourth switch tube M4 in the two-level inverter circuit after passing through the second filter magnetic ring again, and then passes through the second filter magnetic ring. A filter magnetic ring flows in from the third end h of the motor coil, flows out from the first end d of the motor coil, and then flows back to the negative pole of the DC power supply through the first filter magnetic ring again to form a loop.

In the control method of the drive assembly provided by the embodiment of the present application, when the motor coil is excited and the battery pack is charged, the direction of the current passing through the first filter magnetic ring and the second filter magnetic ring is bidirectional, so the first filter magnetic ring The magnetic flux generated on the ring can cancel each other, and the magnetic flux generated on the second filter magnetic ring can also cancel each other, so the first filter magnetic ring and the second filter magnetic ring will not be saturated, which can reduce electromagnetic interference and reduce The impact of EMC on the safe operation of vehicles, and the impact of magnetic ring saturation on filter performance. Moreover, since the loops of the excitation process and the charging process in the present application are integrated inside the drive assembly, the metal shell of the drive assembly can provide shielding, so electromagnetic interference can be further reduced.

The steps of the methods or algorithms described in connection with the disclosure of this application can be implemented in the form of hardware, or can be implemented in the form of a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (random access memory, RAM), flash memory, erasable programmable read-only memory (erasable programmable ROM, EPROM), electrically erasable Programmable read-only memory (electrically EPROM, EEPROM), registers, hard disk, removable hard disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium can be located in the ASIC. In addition, the ASIC may be located in the core network interface device. Certainly, the processor and the storage medium may also exist in the core network interface device as discrete components.

Those skilled in the art should be aware that, in the above one or more examples, the functions described in the present invention may be implemented by hardware, software, firmware or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, any modification, equivalent replacement, improvement, etc. made on the basis of the technical solution of the present invention shall be included in the protection scope of the present invention.

Claims (22)

A drive assembly, characterized in that the drive assembly includes a two-level inverter circuit, a first filter magnetic ring, and a motor coil; the first input terminal and the second input terminal of the two-level inverter circuit terminals are respectively used for coupling and connection with the positive pole and negative pole of the battery pack, and the first input terminal of the two-level inverter circuit is also used for coupling connection with the positive pole of the DC power supply; the three-phase output of the two-level inverter circuit terminals are respectively coupled to the three terminals of the motor coil through the first filter magnetic ring, and the first output terminal of the three-phase output terminals of the two-level inverter circuit passes through the first filter magnetic ring, Used to couple and connect with the negative pole of the DC power supply; the two-level inverter circuit includes a first group of switching tubes and a second group of switching tubes, and the first group of switching tubes and the second group of switching tubes respectively include one or more switching tubes; When the motor coil is excited, the current flows out from the positive pole of the DC power supply, and passes through the first group of switch tubes, the first filter magnetic ring, and the motor coil in the two-level inverter circuit , and flow back to the negative pole of the DC power supply after passing through the first filter magnetic ring again; When charging the battery pack, the current flows out from the positive pole of the DC power supply, passing through the battery pack, the second group of switch tubes in the two-level inverter circuit, and the first filter magnetic ring , the motor coil, and flow back to the negative pole of the DC power supply after passing through the first filter magnetic ring again. The drive assembly according to claim 1, wherein the first group of switching tubes includes a first switching tube, and the second group of switching tubes includes a second switching tube; the first switching tube of the first switching tube end is the first input end of the two-level inverter circuit, and the second end of the first switching tube is the second output end among the three-phase output ends of the two-level inverter circuit; The second end of a switch tube is coupled to the first end of the second switch tube, and the second end of the first switch tube and the first end of the second switch tube are coupled through the first filter magnetic ring To the second end of the motor coil, the second end of the second switch tube is the second input end of the two-level inverter circuit; the third end of the first switch tube and the second The third terminal of the switch tube is the control terminal. The drive assembly according to claim 2, wherein when the motor coil is excited, the first switch tube is in a conduction state, and the second switch tube is in an off state; When the battery pack is charging, the first switch tube is in the off state, and the second switch tube is in the on state. The drive assembly according to claim 2 or 3, wherein the first switch tube and the second switch tube are N-type metal oxide semiconductor MOS tubes, and the first end of the first switch tube is the drain, the second terminal of the first switching tube is the source, the third terminal of the first switching tube is the gate, the first terminal of the second switching tube is the drain, and the second The second end of the switch tube is the source, and the third end of the second switch tube is the gate. The drive assembly according to any one of claims 2-4, wherein the first group of switching tubes further includes a third switching tube, and the second group of switching tubes further includes a fourth switching tube; The first end of the third switch tube is the first input end of the two-level inverter circuit, and the second end of the third switch tube is the three-phase output end of the two-level inverter circuit. The third output end; the second end of the third switch tube is coupled to the first end of the fourth switch tube, and the second end of the third switch tube and the first end of the fourth switch tube pass through The first filtering magnetic ring is coupled to the third end of the motor coil, the second end of the fourth switching tube is the second input end of the two-level inverter circuit; the third switching tube is The third terminal and the third terminal of the fourth switch tube are control terminals. The drive assembly according to claim 5, characterized in that, when the motor coil is excited, the third switch tube is in the conduction state, and the fourth switch tube is in the off state; When the battery pack is charging, the third switch tube is in the off state, and the fourth switch tube is in the on state. The drive assembly according to claim 5 or 6, wherein the third switch tube and the fourth switch tube are N-type MOS tubes, the first terminal of the third switch tube is a drain, The second terminal of the third switching transistor is a source, the third terminal of the third switching transistor is a gate, the first terminal of the fourth switching transistor is a drain, and the first terminal of the fourth switching transistor is a drain. The two terminals are the source, and the third terminal of the fourth switch tube is the gate. The drive assembly according to any one of claims 1-7, characterized in that the drive assembly further comprises a second filter magnetic ring, the first input end of the two-level inverter circuit passes through the The second filter magnetic ring is coupled to the positive pole of the battery pack, and the second input terminal of the two-level inverter circuit is coupled to the negative pole of the battery pack through the second filter magnetic ring; When the motor coil is excited, the current flows out from the positive pole of the DC power supply, and passes through the first group of switch tubes, the first filter magnetic ring, and the motor coil in the two-level inverter circuit , and flow back to the negative pole of the DC power supply through the first filter magnetic ring again; When charging the battery pack, the current flows out from the positive pole of the DC power supply, and passes through the second filter magnetic ring, the battery pack, the second filter magnetic ring, the second group of switch tubes, After the first filter magnetic ring, the motor coil, and the first filter magnetic ring, the flow returns to the negative pole of the DC power supply. The drive assembly according to any one of claims 1-8, characterized in that, when the drive assembly is not used for driving the vehicle, the drive assembly excites the motor coil and excites the battery pack Charge. A control method for a drive assembly, characterized in that the drive assembly includes a two-level inverter circuit, a first filter magnetic ring, and a motor coil; the first input terminal of the two-level inverter circuit and The second input terminal is respectively used for coupling connection with the positive pole and the negative pole of the battery pack, and the first input terminal of the two-level inverter circuit is also used for coupling connection with the positive pole of the DC power supply; the two-level inverter circuit The three-phase output terminals are respectively coupled to the three terminals of the motor coil through the first filter magnetic ring, and the first output terminal of the three-phase output terminals of the two-level inverter circuit passes through the first filter magnetic ring. Before the ring, it is used to couple and connect with the negative pole of the DC power supply; the two-level inverter circuit includes a first group of switching tubes and a second group of switching tubes, and the first group of switching tubes and the second group of switching tubes The tubes respectively include one or more switching tubes; the method includes: When the motor coil is excited, the first set of switch tubes is controlled to be turned on, the second set of switch tubes is turned off, and the current flows from the positive pole of the DC power supply through the two-level inverter circuit The first group of switch tubes, the first filter magnetic ring, the motor coil, and after passing through the first filter magnetic ring again, flow back to the negative pole of the DC power supply; When charging the battery pack, the first set of switch tubes is controlled to be turned off, the second set of switch tubes is turned on, and the current flows out from the positive pole of the DC power supply, passing through the battery pack, the two batteries The second group of switching tubes, the first filter magnetic ring, and the motor coil in the flat inverter circuit flow back to the negative pole of the DC power supply after passing through the first filter magnetic ring again. The control method according to claim 10, wherein the first group of switch tubes includes a first switch tube, and the second group of switch tubes includes a second switch tube; the first end of the first switch tube is the first input end of the two-level inverter circuit, and the second end of the first switching tube is the second output end of the three-phase output ends of the two-level inverter circuit; the first The second end of the switch tube is coupled to the first end of the second switch tube, and the second end of the first switch tube and the first end of the second switch tube are coupled to the The second end of the motor coil, the second end of the second switch tube is the second input end of the two-level inverter circuit; the third end of the first switch tube and the second switch tube The third end of the tube is the control end. The control method according to claim 11, characterized in that, when the motor coil is excited, the first switch tube is in the on state, and the second switch tube is in the off state; When charging the battery pack, the first switch tube is in the off state, and the second switch tube is in the on state. The control method according to claim 11 or 12, wherein the first switch tube and the second switch tube are N-type metal oxide semiconductor MOS tubes, and the first end of the first switch tube is Drain, the second end of the first switch tube is the source, the third end of the first switch tube is the gate, the first end of the second switch tube is the drain, the second switch The second end of the switch tube is the source, and the third end of the second switch tube is the gate. The control method according to any one of claims 11-13, wherein the first group of switching transistors further includes a third switching transistor, and the second group of switching transistors further includes a fourth switching transistor; The first end of the third switching tube is the first input end of the two-level inverter circuit, and the second end of the third switching tube is the third output end of the three-phase output end of the two-level inverter circuit. Three output ends; the second end of the third switch tube is coupled to the first end of the fourth switch tube, and the second end of the third switch tube and the first end of the fourth switch tube pass through the first end of the fourth switch tube. The first filtering magnetic ring is coupled to the third end of the motor coil, the second end of the fourth switch tube is the second input end of the two-level inverter circuit; the first end of the third switch tube is The three terminals and the third terminal of the fourth switch tube are control terminals. The control method according to claim 14, characterized in that, when the motor coil is excited, the third switch tube is in the on state, and the fourth switch tube is in the off state; When the battery is charging, the third switch tube is in the off state, and the fourth switch tube is in the on state. The control method according to claim 14 or 15, characterized in that, the third switch tube and the fourth switch tube are N-type MOS tubes, and the first terminal of the third switch tube is a drain, so The second terminal of the third switching tube is the source, the third terminal of the third switching tube is the grid, the first terminal of the fourth switching tube is the drain, and the second terminal of the fourth switching tube is the drain. terminal is the source, and the third terminal of the fourth switch tube is the gate. The control method according to any one of claims 10-16, wherein the drive assembly further includes a second filter magnetic ring, and the first input end of the two-level inverter circuit passes through the first The second filter magnetic ring is coupled to the positive pole of the battery pack, and the second input terminal of the two-level inverter circuit is coupled to the negative pole of the battery pack through the second filter magnetic ring; When the motor coil is excited, the current flows out from the positive pole of the DC power supply, and passes through the first group of switch tubes, the first filter magnetic ring, and the motor coil in the two-level inverter circuit , and flow back to the negative pole of the DC power supply through the first filter magnetic ring again; When charging the battery pack, the current flows out from the positive pole of the DC power supply, and passes through the second filter magnetic ring, the battery pack, the second filter magnetic ring, the second group of switch tubes, After the first filter magnetic ring, the motor coil, and the first filter magnetic ring, the flow returns to the negative pole of the DC power supply. The control method according to claim 17, characterized in that, when the drive assembly is not used to drive the vehicle, the drive assembly excites the motor coil and charges the battery pack. A charging system, characterized in that the charging system includes a power distribution circuit, and the drive assembly according to any one of claims 1-9, the first input terminal of the two-level inverter circuit passes through The power distribution circuit is coupled and connected to the positive pole of the DC power supply. An electrical equipment, characterized in that the electrical equipment includes a power distribution circuit, and the drive assembly according to any one of claims 1-9, the first input of the two-level inverter circuit The terminal is coupled and connected to the positive pole of the DC power supply through the power distribution circuit. The electric device according to claim 20, further comprising the battery pack. The electric device according to claim 20 or 21, wherein the electric device is a car.

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