CN218549757U - Three-phase staggered wide-range efficient isolation bidirectional converter - Google Patents

Abstract

The utility model discloses a three-phase interleaved wide-range high-efficiency isolation bidirectional converter, which comprises a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge rectifier circuit, the resonant cavity includes three resonant circuits, and the resonant The circuit includes a first capacitance, a second capacitance, a third capacitance, a first inductance, a second inductance and a third inductance, one end of the first inductance is connected to one end of the second inductance, the first capacitance and the third capacitance, and the first The other ends of the inductance and the first capacitor are respectively connected to one end of the third inductance and the second capacitor, the one end of the third inductance is connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the other end of the second inductance and the third capacitor One end is respectively connected to the other end of the third inductor and the second capacitor, and is connected to the primary winding of a transformer, and the ends connected to the second capacitor and the first capacitor in the three resonant circuits are respectively connected to each other to form a Y-shaped connection, and the three transformers The primary windings are respectively connected to the midpoints of the three bridge arms of the three-phase bridge rectifier circuit.

Description

A three-phase interleaved wide-range high-efficiency isolated bidirectional converter

technical field

The utility model relates to the technical field of power conversion, in particular to a three-phase interleaved wide-range high-efficiency isolation bidirectional converter.

Background technique

The DC-DC bidirectional converter is a DC/DC converter that can adjust the bidirectional transmission of energy according to the needs. It is mainly used in energy storage systems, vehicle power systems, feedback charging and discharging systems, hybrid energy electric vehicles and other occasions. As the industry continues to With the development, the power has been continuously increased from kilowatts to tens of kilowatts, and the topology that can achieve high power, wide range, positive and negative symmetry, and high efficiency has become the general trend.

In the traditional LLC resonant bidirectional converter, the ZVS conduction of the switch tube on the primary side and the ZCS conduction of the diode on the rectification side can be realized regardless of forward and reverse operation, but its circuit characteristics are no longer when the energy flows in the reverse direction. It is the LLC resonance characteristic and degenerates into the LC resonance characteristic. The maximum voltage gain of the LC resonance becomes 1, which greatly reduces the voltage gain during the reverse operation, and cannot realize the normal reverse output, so that the forward and reverse completely symmetrical bidirectional cannot be realized; In order to achieve completely symmetrical bidirectional energy flow, the industry adopts DAB or adds a first-level topology circuit on the basis of LLC to make up for the lack of reverse gain capability of LLC, basically realizing completely symmetrical bidirectional, but the DAB hard switch and LLC two-level topology structure, All will bring the problem of low efficiency, especially for higher power bidirectional DC-DC, due to the inherent problems of DAB or two-stage topology, as the power continues to increase, the heat and ripple of high-power bidirectional DC-DC will become more and more Difficult to handle and will eventually become a bottleneck.

Utility model content

The technical problem to be solved by the utility model is to provide a three-phase interleaved wide-range high-efficiency isolation bidirectional converter that can reduce ripples and simultaneously realize a wide range, completely symmetrical positive and negative gains, and high efficiency.

In order to solve the above technical problems, the utility model provides a three-phase interleaved wide-range high-efficiency isolated bidirectional converter, including a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge rectifier circuit, the three-phase bridge One side of the type switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter. The resonant cavity includes three resonant circuits, and the three The resonant circuits are connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers respectively, wherein,

The resonant circuit includes a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, and a third inductor, and one end of the first inductor is connected to one end of the second inductor, the first capacitor, and the third capacitor , the other end of the first inductance and the first capacitor are respectively connected to one end of the third inductance and the second capacitor, the one end of the third inductance is connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the first The other ends of the second inductance and the third capacitor are respectively connected to the other end of the third inductance and the second capacitor, and are connected to the primary winding of a transformer, and one end of the second capacitor connected to the first capacitor in the three resonant circuits is connected to each other respectively. The connection forms a Y-shaped connection. The same-named ends of the three transformer secondary windings correspond to the midpoints of the three bridge arms connected to the three-phase bridge rectifier circuit, and the different-named ends of the three transformer secondary windings are connected to each other to form a Y-shaped connection. .

Its further technical solution is: the three-phase bridge switching circuit includes six switching tubes, every two switching tubes are connected in series to form a bridge arm, and after the three bridge arms are connected in parallel, the two ends thereof serve as three-phase interleaved wide-range high-efficiency isolated bidirectional conversion the first connection side of the device.

Its further technical solution is: the three-phase bridge rectifier circuit includes six switching tubes, every two switching tubes are connected in series to form a bridge arm, and after the three bridge arms are connected in parallel, their two ends serve as three-phase interleaved wide-range high-efficiency isolated bidirectional conversion the second connection side of the device.

Its further technical solution is: the switch tube is selected from MOSFET, IGBT tube, GaN tube or SiC power tube.

Its further technical solution is: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter also includes a first filter capacitor and a second filter capacitor, and both ends of the first filter capacitor are connected to the three-phase interleaved wide-range high-efficiency isolated bidirectional converter The first connection side of the second filter capacitor is connected to the second connection side.

In order to solve the above technical problems, the utility model also provides a three-phase interleaved wide-range high-efficiency isolated bidirectional converter, including a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge rectifier circuit, the three-phase One side of the bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, the resonant cavity includes three resonant circuits, and the three The resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein,

The resonant circuit includes a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, and a third inductor, and one end of the first inductor is connected to one end of the second inductor, the first capacitor, and the third capacitor , the other end of the first inductance and the first capacitor are respectively connected to one end of the third inductance and the second capacitor, the one end of the second capacitor is connected to the midpoint of a bridge arm in the three-phase bridge switch circuit, the first The other ends of the second inductance and the third capacitor are respectively connected to the other end of the third inductance and the second capacitor, and are connected to the primary winding of a transformer, and one end of the third inductance and the first inductance in the three resonant circuits are connected to each other respectively The connection forms a Y-shaped connection. The same-named ends of the three transformer secondary windings correspond to the midpoints of the three bridge arms connected to the three-phase bridge rectifier circuit, and the different-named ends of the three transformer secondary windings are connected to each other to form a Y-shaped connection. .

In order to solve the above technical problems, the utility model also provides a three-phase interleaved wide-range high-efficiency isolated bidirectional converter, including a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge rectifier circuit, the three-phase One side of the bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, the resonant cavity includes three resonant circuits, and the three The resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein,

The resonant circuit includes a first capacitor, a second capacitor, a first inductance, a second inductance and a third inductance, one end of the first inductance and the second inductance are connected to one end of the first capacitor and the second capacitor, the first The other end of an inductance is connected to one end of a third inductance and to the midpoint of a bridge arm in a three-phase bridge switch circuit, the other end of the second inductance and the second capacitor are connected to a primary winding of a transformer, and The other end of the second inductance is connected to the other end of the third inductance, and the other ends of the first capacitors in the three resonant circuits are respectively connected to each other to form a Y-shaped connection, and the terminals with the same name of the three transformer secondary windings are respectively connected to three The midpoints of the three bridge arms of the phase bridge rectifier circuit and the opposite ends of the three transformer secondary windings are respectively connected to each other to form a Y-shaped connection.

In order to solve the above technical problems, the utility model also provides a three-phase interleaved wide-range high-efficiency isolated bidirectional converter, including a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge rectifier circuit, the three-phase One side of the bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, the resonant cavity includes three resonant circuits, and the three The resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein,

The resonant circuit includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor, one end of the first inductor is connected to the first capacitor and one end of the third inductor, and one end of the second inductor Connect the other end of the third inductor to one end of the second capacitor, the other end of the first capacitor is connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the other end of the second inductor is connected to the second capacitor The primary winding of a transformer, and the other end of the second inductance is connected to the other end of the first inductance, and the same-named ends of the three transformer secondary windings are respectively connected to the midpoints of the three bridge arms of the three-phase bridge rectifier circuit, The opposite ends of the primary windings and secondary windings of the three transformers are respectively connected to each other to form a Y-shaped connection.

Compared with the prior art, each circuit in the three-phase interleaving wide-range high-efficiency isolation bidirectional converter of the utility model adopts the three-phase interleaving technology to reduce the ripple, and the equivalent circuit of the resonant circuit in it when the energy flows forward and reverse Both are multi-element resonant circuits, which realize soft switching when working in the forward and reverse directions, and the loss is small, which solves the problem that the traditional LLC resonant circuit cannot work in the reverse direction with the same performance. When the energy flows in the reverse direction, the voltage can be boosted, which can effectively increase the input and output voltage range of the converter, and realize the output of a wide voltage range. Frequency modulation control can realize wide voltage range output without broadband control, that is, switching control frequency can be compressed and narrowed to improve efficiency.

Description of drawings

Fig. 1 is a schematic circuit diagram of the first embodiment of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter of the present invention.

Fig. 2 is a schematic circuit diagram of the second embodiment of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter of the present invention.

Fig. 3 is a schematic circuit diagram of a third embodiment of a three-phase interleaved wide-range high-efficiency isolated bidirectional converter of the present invention.

Fig. 4 is a schematic circuit diagram of a fourth embodiment of a three-phase interleaved wide-range high-efficiency isolated bidirectional converter of the present invention.

Detailed ways

In order to make those skilled in the art more clearly understand the purpose, technical solutions and advantages of the utility model, the utility model will be further elaborated below in conjunction with the accompanying drawings and embodiments.

Referring to FIG. 1 , FIG. 1 is a schematic circuit diagram of a first embodiment of a three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10 of the present invention. In the embodiment shown in the accompanying drawings, the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10 includes a three-phase bridge switch circuit 100, a resonant cavity 200, three transformers, and a three-phase bridge rectifier circuit 300. One side of the three-phase bridge switch circuit 100 and the three-phase bridge rectifier circuit 300 are respectively used as the first connection side and the second connection side of the converter 10 to connect the power supply or the load, and the resonant cavity 200 includes three resonant The three resonant circuits are correspondingly connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit 100 and the three primary windings of the transformer. Wherein, the resonant circuit includes a first capacitor, a second capacitor, a third capacitor, a first inductance, a second inductance and a third inductance, and one end of the first inductance is connected to the second inductance, the first capacitor and the third capacitor One end of the first inductance and the first capacitor are respectively connected to one end of the third inductance and one end of the second capacitor, and the one end of the third inductance is connected to the midpoint of a bridge arm in the three-phase bridge switch circuit 100, The other ends of the second inductance and the third capacitor are respectively connected to the other end of the third inductance and the second capacitor, and connected to the primary winding of a transformer, and the second capacitor connected to the first capacitor in the three resonant circuits One ends are connected to each other to form a Y-shaped connection, the same-named ends of the three transformer secondary windings are respectively connected to the midpoints of the three bridge arms of the three-phase bridge rectifier circuit 300, and the different-named ends of the three transformer secondary windings are respectively connected to each other Form a Y-connection. Preferably, the inductance of the first inductor and the second inductor in the resonant circuit are the same, and the capacitance of the first capacitor and the third capacitor are the same. Understandably, a Y-shaped connection is used in the resonant circuit, and the total current flowing into the midpoint of the Y-shaped connection is equal to the total current flowing out of the midpoint of the Y-shaped connection, that is, the sum of the currents of the three resonant circuits is "0", so any There is always a resonant circuit whose current is the sum of the currents of the other two resonant circuits. Even if the resonant parameters of each resonant circuit have a certain tolerance during the entire switching cycle, their current RMS deviation is also small. Therefore, the current balance among the three resonant circuits is ensured, and the damage or overheating of the components of the circuit caused by the excessive current of a certain resonant circuit is avoided.

Specifically, in this embodiment, the resonant cavity 200 includes a first resonant circuit, a second resonant circuit, and a third resonant circuit, and the three transformers include a first transformer T1, a second transformer T2, and a third transformer T3. The first resonant circuit includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductance L1, a second inductance L2, and a third inductance L3, and the second resonant circuit includes a first capacitor C4, a second capacitor C5, the third capacitor C6, the first inductor L4, the second inductor L5 and the third inductor L6, the third resonant circuit includes the first capacitor C7, the second capacitor C8, the third capacitor C9, the first inductor L7, the third capacitor The second inductance L8 and the third inductance L9, in the embodiment shown in the drawings, the third inductance L3, the third inductance L6 and the third inductance L9 respectively correspond to the three phases connected to the three-phase bridge switch circuit 100 At the midpoint of the bridge arm, the second capacitor C2, the second capacitor C5, and the second capacitor C8 are connected to each other to form a Y-shaped connection, and the second inductor L2, the second inductor L5, and the second inductor L8 are respectively connected to the first transformer T1, The same-named ends of the primary windings of the second transformer T2 and the third transformer T3; and the third capacitor C3, the third capacitor C6 and the third capacitor C9 are respectively connected to the primary windings of the first transformer T1, the second transformer T2 and the third transformer T3 Synonymous end.

In this embodiment, when the energy flows in the forward direction, that is, when the energy flows from the first connection side to the second connection side, the first connection side of the three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10 is used as a DC input terminal, which can be connected to an external The power supply, whose second connection side is used as a DC output terminal, can be connected to an external load; and when the energy flows in the opposite direction, that is, when the energy flows from the second connection side to the first connection side, a three-phase interleaved wide-range high-efficiency isolation bidirectional converter The second connection side of 10 is used as a DC input terminal, and the first connection side thereof is used as a DC output terminal. The utility model three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10 has a simple structure, and the equivalent circuit of the resonant circuit is a multi-element resonant circuit when the energy flows in the forward and reverse directions, and can realize soft switching when working in the forward and reverse directions, and the loss is small , which solves the problem of insufficient reverse gain of the traditional LLC resonant circuit, that is, when the energy flows from the second connection side to the first connection side, the voltage can be boosted, which can effectively increase the input and output voltage range of the converter 10, and realize wide voltage range input output, which can be applied to high-power circuits; and compared with the switching frequency of the three-phase interleaved bidirectional converter in the prior art, which needs broadband control to realize the input and output of a wide range of voltage, the utility model has a three-phase interleaved wide-range high-efficiency isolation bidirectional Because the resonant frequency of the redesigned resonant circuit of the converter 10 is relatively small, wide voltage range output can be realized without broadband control when switching frequency modulation control is adopted, that is, the switching control frequency can be compressed and narrowed to improve efficiency.

In some embodiments, the three-phase bridge switching circuit 100 includes a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, a fourth switching tube Q4, a fifth switching tube Q5 and a sixth switching tube. The tube Q6 has six switch tubes in total, and every two switch tubes are connected in series to form a bridge arm. After the three bridge arms are connected in parallel, the two ends thereof serve as the first connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10, wherein the The midpoint of the bridge arm formed by the first switching tube Q1 and the second switching tube Q2 in series is connected to the first resonant circuit, and the midpoint of the bridge arm formed by the third switching tube Q3 and the fourth switching tube Q4 in series is connected to the second The resonant circuit is connected, and the midpoint of the bridge arm formed by the fifth switching tube Q5 and the sixth switching tube Q6 connected in series is connected to the third resonant circuit. In this embodiment, the PFM mode is used to control the operation of the switch tube, that is, a constant duty cycle is adopted, the on and off time of the switch tube is constant, and then the adjustment is realized by modulating the frequency of the square wave. The three methods in the prior art The switching frequency of the phase-interleaved bidirectional converter needs wide-band control in order to realize a wide range of voltage input and output. That is, when it is necessary to boost the voltage from 40v to 400v, the switching frequency needs to be fully loaded. However, the control range of the switching frequency of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10 of the present invention is relatively small, and the switching frequency is only 160KHZ at full load when the boost gain is the same, and the efficiency is high.

In the embodiment shown in the drawings, the three-phase bridge rectifier circuit 300 includes a seventh switching tube Q7, an eighth switching tube Q8, a ninth switching tube Q9, a tenth switching tube Q10, and an eleventh switching tube Q11. And the twelfth switching tube Q12 six switching tubes, every two switching tubes are connected in series to form a bridge arm, and the two ends of the three bridge arms are connected in parallel as the second connection side of the three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10, Wherein, the midpoint of the bridge arm composed of the seventh switching tube Q7 and the eighth switching tube Q8 connected in series is connected to the secondary winding of the first transformer T1, and the ninth switching tube Q9 and the tenth switching tube Q10 are connected in series. The midpoint of the bridge arm is connected to the secondary winding of the second transformer T2, and the midpoint of the bridge arm composed of the eleventh switching transistor Q11 and the twelfth switching transistor Q12 connected in series is connected to the secondary winding of the third transformer T3. Based on this design, when the energy flows in the forward direction, the three-phase bridge rectifier circuit 300 can rectify the voltage waveform periodically output by the transformer to generate the working voltage required by the load. Preferably, the switch tube can be selected from MOSFET, IGBT tube, GaN tube, SiC power tube or other controllable power switch tubes to achieve better circuit performance. In some other embodiments, each switch tube A diode can also be connected in parallel.

Further, the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10 also includes a first filter capacitor C10 and a second filter capacitor C11, both ends of the first filter capacitor C10 are connected to the three-phase interleaved wide-range high-efficiency isolated bidirectional converter The first connection side of the converter 10, the two ends of the second filter capacitor C11 are connected to the second connection side of the three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10.

Understandably, in this embodiment, when the energy is forwardly transmitted, by controlling the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, the fourth switching tube Q4, the fifth switching tube Q5 and the sixth switching tube The switching frequency of the switching tube Q6 is used to realize the wide-range voltage output of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10, and the two switching tubes on each bridge arm are complementary to conduction, which can realize soft switching of the circuit; energy reverse transmission , the equivalent circuit of the resonant circuit is also a multi-element resonant circuit, therefore, by controlling the seventh switching tube Q7, the eighth switching tube Q8, the ninth switching tube Q9, the tenth switching tube Q10, the eleventh switching tube Q11 and The switching frequency of the twelfth switching tube Q12 can realize the same wide-range voltage output as that in the forward transmission, and the two switching tubes on each bridge arm are conducted complementary to realize soft switching of the circuit.

The three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10 of the utility model adopts three-phase interleaved technology, the conduction phase difference between Q1 and Q2, Q3 and Q4, Q5 and Q6 is 180 degrees, and the conduction sequence of Q1, Q3 and Q5 Therefore, the conduction sequence of Q2, Q4, and Q6 is also 120 degrees different from each other, and the difference between the three-phase input and output currents is 120 degrees. The input and output current fluctuations of the three-phase circuit are complementary, so that the input and output current ripples are smaller. Thereby achieving better circuit performance. At any moment, at least one or at most two of Q1, Q3, and Q5 are turned on, and at least one or at most two of Q2, Q4, and Q6 are turned on, and the number of turned-on switch tubes is always equal to three. Taking one of the three resonant circuits as an example, when Q1, Q4, and Q6 are turned on, the resonant DC voltage is transmitted to the first transformer T1 through the first switching tube Q1, and at the same time, the current value of the first resonant circuit increases to store can, at the same time, the seventh switching tube Q7 is turned on, and the second filter capacitor C11 realizes rectifying and filtering the output voltage of the first transformer T1, so as to output a stable voltage and control the output current; when Q2, Q3 and Q5 are turned on , the resonant DC reverse voltage is transmitted to the first transformer T1 through the second switch tube Q2, and at the same time, the reverse current value of the first resonant circuit increases to supply power to the first transformer T1, and the eighth switch tube Q8 is turned on to realize the first transformer T1 The output voltage of a transformer T1 is rectified and filtered to output a stable voltage and control the output current. In the same way, the working principle of the other two resonant circuits is consistent with this way.

Referring to Fig. 2, Fig. 2 is a schematic circuit diagram of the second embodiment of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter 10 of the present invention. The difference between this embodiment and the first embodiment lies in the resonant circuit in the resonant cavity 200 and the inverter The circuit and the specific connection of the transformer are different, and the rest of the circuit structure is the same or similar. In this embodiment, the midpoint of the bridge arm composed of the first switching tube Q1 and the second switching tube Q2 in series is connected to the second capacitor C2 in the first resonant circuit, and the third switching tube Q3 and the fourth switching tube The midpoint of the bridge arm formed by the series connection of the transistor Q4 is connected to the second capacitor C5 in the second resonant circuit, and the midpoint of the bridge arm formed by the series connection of the fifth switching transistor Q5 and the sixth switching transistor Q6 is connected to the second capacitance C5 in the third resonant circuit. Two capacitors C8 are connected, the third inductor L3, the third inductor L6 and the third inductor L9 are respectively connected to each other to form a Y-shaped connection, and the third capacitor C3, the third capacitor C6 and the third capacitor C9 are respectively connected to the first transformer T1 , the primary windings of the second transformer T2 and the third transformer T3 with the same name; and the second inductance L2, the second inductance L5 and the second inductance L8 are respectively connected to the primary windings of the first transformer T1, the second transformer T2 and the third transformer T3 The heteronym.

Referring to FIG. 3 , FIG. 3 is a schematic circuit diagram of the third embodiment of the three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10 of the present invention. The difference between this embodiment and the first embodiment lies in the specific structure of the resonant circuit in the resonant cavity 200 Different, the rest of the circuit structure is the same or similar. In this embodiment, the resonant circuit includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor, and one end of the first inductor and the second inductor are connected to the first capacitor and the second capacitor One end of the first inductance, the other end of the first inductance is connected to one end of the third inductance, and connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the other end of the second inductance and the second capacitor are connected to a transformer The other end of the second inductance is connected to the other end of the third inductance, and the other ends of the first capacitors in the three resonant circuits are respectively connected to each other to form a Y-shaped connection.

As can be seen from the figure, specifically, the resonant cavity 200 includes a first resonant circuit, a second resonant circuit and a third resonant circuit, and the first resonant circuit includes a first capacitor C1, a second capacitor C2, a first inductor L1, The second inductance L2 and the third inductance L3, the second resonant circuit includes a first capacitor C3, the second capacitor C4, the first inductance L4, the second inductance L5 and the third inductance L6, the third resonant circuit includes the first A capacitor C5, a second capacitor C6, a first inductance L7, a second inductance L8 and a third inductance L9, in the embodiment shown in the accompanying drawings, the third inductance L3, the third inductance L6 and the third inductance L9 One end of the third inductance L3, the third inductance L6 and the third inductance L9 are respectively connected to the midpoints of the three bridge arms of the three-phase bridge switch circuit 100, and the other ends of the third inductance L3, the third inductance L6 and the third inductance L9 are respectively connected to the first transformer T1 and the third inductance L9 respectively. The terminals with the same name of the primary windings of the second transformer T2 and the third transformer T3, the second capacitor C2, the second capacitor C4 and the second capacitor C6 are respectively connected to the different names of the primary windings of the first transformer T1, the second transformer T2 and the third transformer T3 terminal, the first capacitor C1 , the first capacitor C3 and the first capacitor C5 are respectively connected to each other to form a Y-shaped connection. This embodiment can also effectively increase the input and output voltage range of the converter 10, and realize wide voltage range input and output, and can realize wide voltage range output without broadband control when using switch frequency modulation control, that is, the switch control frequency can be compressed and narrowed ,Improve efficiency.

Referring to Fig. 4, Fig. 4 is a schematic circuit diagram of the fourth embodiment of the three-phase interleaved wide-range high-efficiency isolation bidirectional converter 10 of the present invention. The difference between this embodiment and the first embodiment lies in the specific structure of the resonant circuit in the resonant cavity 200 Different, the rest of the circuit structure is the same or similar. In this embodiment, the resonant circuit includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor, one end of the first inductor is connected to one end of the first capacitor and the third inductor, and the One end of the second inductance is connected to the other end of the third inductance and one end of the second capacitor, the other end of the first capacitor is connected to the midpoint of a bridge arm in the three-phase bridge switch circuit, the second inductance and the second The other end of the capacitor is connected to the primary winding of a transformer, and the other end of the second inductor is connected to the other end of the first inductor.

As can be seen from the figure, specifically, the resonant cavity 200 includes a first resonant circuit, a second resonant circuit and a third resonant circuit, and the first resonant circuit includes a first capacitor C1, a second capacitor C2, a first inductor L1, The second inductance L2 and the third inductance L3, the second resonant circuit includes a first capacitor C3, the second capacitor C4, the first inductance L4, the second inductance L5 and the third inductance L6, the third resonant circuit includes the first A capacitor C5, a second capacitor C6, a first inductance L7, a second inductance L8 and a third inductance L9, in the embodiment shown in the drawings, the first capacitor C1, the first capacitor C3 and the first capacitor C5 The midpoints of the three bridge arms of the three-phase bridge switch circuit 100 are respectively connected correspondingly, and the second capacitor C2, the second capacitor C4 and the second capacitor C6 are respectively connected correspondingly to the first transformer T1, the second transformer T2 and the The terminal with the same name of the primary winding of the third transformer T3, the second inductance L2, the second inductance L5 and the second inductance L8 are respectively connected to the terminals with the same name of the primary winding of the first transformer T1, the second transformer T2 and the third transformer T3, In addition, the opposite ends of the primary windings and secondary windings of the first transformer T1 , the second transformer T2 and the third transformer T3 are respectively connected to each other to form a Y-shaped connection.

In summary, each circuit in the three-phase interleaved wide-range high-efficiency isolation bidirectional converter of the present invention can reduce ripples by using three-phase interleaved technology, and the equivalent circuit of the resonant circuit in it is The multi-element resonant circuit realizes soft switching when working in the forward and reverse directions, and the loss is small, which solves the problem that the traditional LLC resonant circuit cannot work in the reverse direction with the same performance. It can boost the voltage when it flows in the opposite direction, which can effectively increase the input and output voltage range of the converter, and realize the output in a wide voltage range. Wide voltage range output can be realized without broadband control, that is, the switching control frequency can be compressed and narrowed to improve efficiency.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model in any form. Those skilled in the art can make various equivalent changes and improvements on the basis of the above-mentioned embodiments, and all equivalent changes or modifications made within the scope of the claims shall fall within the protection scope of the present utility model.

Claims (8)

1. A three-phase interleaved wide-range high-efficiency isolated bidirectional converter, characterized in that: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter comprises a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge A rectifier circuit, one side of the three-phase bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, and the resonant cavity includes three three resonant circuits, the three resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein, The resonant circuit includes a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, and a third inductor, and one end of the first inductor is connected to one end of the second inductor, the first capacitor, and the third capacitor , the other end of the first inductance and the first capacitor are respectively connected to one end of the third inductance and the second capacitor, the one end of the third inductance is connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the first The other ends of the second inductance and the third capacitor are respectively connected to the other end of the third inductance and the second capacitor, and are connected to the primary winding of a transformer, and one end of the second capacitor connected to the first capacitor in the three resonant circuits is connected to each other respectively. The connection forms a Y-shaped connection. The same-named ends of the three transformer secondary windings correspond to the midpoints of the three bridge arms connected to the three-phase bridge rectifier circuit, and the different-named ends of the three transformer secondary windings are connected to each other to form a Y-shaped connection. . 2. The three-phase interleaved wide-range high-efficiency isolated bidirectional converter as claimed in claim 1, characterized in that: the three-phase bridge switch circuit includes six switch tubes, and every two switch tubes are connected in series to form a bridge arm, and three After the two bridge arms are connected in parallel, the two ends thereof serve as the first connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter. 3. The three-phase interleaved wide-range high-efficiency isolated bidirectional converter as claimed in claim 1, characterized in that: the three-phase bridge rectifier circuit includes six switch tubes, and every two switch tubes are connected in series to form a bridge arm, three After the two bridge arms are connected in parallel, the two ends thereof serve as the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter. 4. The three-phase interleaved wide-range high-efficiency isolated bidirectional converter according to claim 2 or 3, wherein the switch tube is a MOSFET, an IGBT tube, a GaN tube or a SiC power tube. 5. The three-phase interleaved wide-range high-efficiency isolated bidirectional converter according to claim 1, characterized in that: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter further comprises a first filter capacitor and a second filter capacitor, the Both ends of the first filter capacitor are connected to the first connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, and both ends of the second filter capacitor are connected to the second connection side. 6. A three-phase interleaved wide-range high-efficiency isolated bidirectional converter, characterized in that: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter includes a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge A rectifier circuit, one side of the three-phase bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, and the resonant cavity includes three three resonant circuits, the three resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein, The resonant circuit includes a first capacitor, a second capacitor, a third capacitor, a first inductor, a second inductor, and a third inductor, and one end of the first inductor is connected to one end of the second inductor, the first capacitor, and the third capacitor , the other end of the first inductance and the first capacitor are respectively connected to one end of the third inductance and the second capacitor, the one end of the second capacitor is connected to the midpoint of a bridge arm in the three-phase bridge switch circuit, the first The other ends of the second inductance and the third capacitor are respectively connected to the other end of the third inductance and the second capacitor, and are connected to the primary winding of a transformer, and one end of the third inductance and the first inductance in the three resonant circuits are connected to each other respectively The connection forms a Y-shaped connection. The same-named ends of the three transformer secondary windings correspond to the midpoints of the three bridge arms connected to the three-phase bridge rectifier circuit, and the different-named ends of the three transformer secondary windings are connected to each other to form a Y-shaped connection. . 7. A three-phase interleaved wide-range high-efficiency isolated bidirectional converter, characterized in that: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter includes a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge A rectifier circuit, one side of the three-phase bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, and the resonant cavity includes three three resonant circuits, the three resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein, The resonant circuit includes a first capacitor, a second capacitor, a first inductance, a second inductance and a third inductance, one end of the first inductance and the second inductance are connected to one end of the first capacitor and the second capacitor, the first The other end of an inductance is connected to one end of a third inductance and to the midpoint of a bridge arm in a three-phase bridge switch circuit, the other end of the second inductance and the second capacitor are connected to a primary winding of a transformer, and The other end of the second inductance is connected to the other end of the third inductance, and the other ends of the first capacitors in the three resonant circuits are respectively connected to each other to form a Y-shaped connection, and the terminals with the same name of the three transformer secondary windings are respectively connected to three The midpoints of the three bridge arms of the phase bridge rectifier circuit and the opposite ends of the three transformer secondary windings are respectively connected to each other to form a Y-shaped connection. 8. A three-phase interleaved wide-range high-efficiency isolated bidirectional converter, characterized in that: the three-phase interleaved wide-range high-efficiency isolated bidirectional converter includes a three-phase bridge switch circuit, a resonant cavity, three transformers and a three-phase bridge A rectifier circuit, one side of the three-phase bridge switch circuit and the three-phase bridge rectifier circuit are respectively used as the first connection side and the second connection side of the three-phase interleaved wide-range high-efficiency isolated bidirectional converter, and the resonant cavity includes three three resonant circuits, the three resonant circuits are respectively connected between the midpoints of the three bridge arms of the three-phase bridge switch circuit and the primary windings of the three transformers, wherein, The resonant circuit includes a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor, one end of the first inductor is connected to the first capacitor and one end of the third inductor, and one end of the second inductor Connect the other end of the third inductor to one end of the second capacitor, the other end of the first capacitor is connected to the midpoint of a bridge arm in the three-phase bridge switching circuit, the other end of the second inductor is connected to the second capacitor The primary winding of a transformer, and the other end of the second inductance is connected to the other end of the first inductance, and the same-named ends of the three transformer secondary windings are respectively connected to the midpoints of the three bridge arms of the three-phase bridge rectifier circuit, The opposite ends of the primary windings and secondary windings of the three transformers are respectively connected to each other to form a Y-shaped connection.

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