CN115377935A - Short-circuit protection system and method for parallel power supply modules - Google Patents

Abstract

The invention relates to a short-circuit protection system and method for parallel power supply modules, which is characterized in that it includes a single-chip microcomputer and several protection circuits, wherein each protection circuit corresponds to a certain power supply module in the power supply system, and each protection circuit includes a current A detection unit, a current comparison unit, a control unit, and a relay; the single-chip microcomputer is used to output a control signal to each control unit according to the requirements of turning on or off the relay; the current detection unit is used to detect the current sampling value of the circuit where the corresponding power module is located; The current comparison unit is used to compare the current sampling value detected by the corresponding current detection unit with the current set value to obtain a current comparison signal; the control unit is used to perform an AND operation on the current comparison signal and the control signal output by the microcontroller, and output the control signal The relay is used to control the on-off of the circuit where the corresponding power supply module is located based on the control level output by the control unit. The present invention can be widely used in the protection field of parallel power supply modules.

Description

A short-circuit protection system and method for parallel power supply modules

technical field

The invention relates to the protection field of parallel power supply modules, in particular to a short-circuit protection system and method for parallel power supply modules.

Background technique

At present, the power of a single module of the existing power module cannot be very large, so when the power system has a high power demand, it is usually necessary to connect several power modules in parallel to increase the power output. However, if there is a short circuit at the input end of a certain power supply module during the parallel output process, it will cause a short circuit at the input end of the entire power supply system, thereby causing the failure of the entire power supply system. In order to prevent this from happening, it is necessary to add a short-circuit protection function to the input end of the power system.

However, the short-circuit protection method in the prior art has a slow response speed and needs to add a lot of additional devices such as micro-control units and latch devices. The cost is high and the fault branch cannot be cut off quickly, which cannot meet the needs of parallel modules in the power system. Short circuit protection needs.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a low-cost short-circuit protection system and method for parallel power supply modules that can quickly cut off the faulty branch.

In order to achieve the above object, the present invention adopts the following technical solutions: On the one hand, a short-circuit protection system for parallel power supply modules is provided, including a single-chip microcomputer and several protection circuits, wherein each protection circuit corresponds to a certain power supply module in the power supply system , and each of the protection circuits includes a current detection unit, a current comparison unit, a control unit and a relay;

The single-chip microcomputer is used to output a control signal to each of the control units according to the requirement of turning on or off the relay;

The current detection unit is used to detect the current sampling value corresponding to the circuit where the power module is located;

The current comparison unit is used to compare the current sampling value detected by the current detection unit with the current setting value to obtain a current comparison signal;

The control unit is used to perform an AND operation on the current comparison signal and the control signal output by the single-chip microcomputer, and output the control level;

The relay is used to control the on-off of the circuit corresponding to the power module based on the control level output by the control unit.

Further, each of the protection circuits further includes a voltage dividing unit, which is used to divide the voltage of the power supply system to a preset voltage according to a certain ratio and send the voltage to the current comparison unit.

Further, each of the protection circuits further includes a reset circuit, each of the reset circuits is respectively connected to the single-chip microcomputer, and the reset circuit is used to reset the circuit corresponding to the power module.

Further, each of the current comparison units includes a comparator and a diode, the comparator is used to output a current comparison signal to the control unit according to the current sampling value and the current setting value, and the diode is used to act as the relay When the circuit corresponding to the power module is disconnected, it is ensured that the output voltage of the comparator will not become high.

Further, in one of the protection circuits, one end of the reset circuit is connected to the input end of the power system, and the other end of the reset circuit is connected in parallel to the comparator through the first voltage dividing resistor in the voltage dividing unit The first input terminal of the voltage dividing unit and one terminal of the second voltage dividing resistor in the voltage dividing unit, the second input terminal of the comparator is connected to the current detection unit, and the output terminal of the comparator is connected in parallel to the control unit The input terminal of the diode and the negative terminal of the diode, the positive terminal of the diode and the other end of the second voltage dividing resistor are respectively grounded; the output terminal of the control unit is connected to the input terminal of the relay, and the The output terminal is connected to correspond to the power module.

On the other hand, a short-circuit protection method for parallel power supply modules is provided, including:

In the power supply system, the current detection unit of each protection circuit detects the current sampling value of the circuit where the corresponding power supply module is located, and sends it to the corresponding current comparison unit;

The current comparison unit of each protection circuit compares the received current sampling value with the preset current setting value to obtain a current comparison signal and send it to the corresponding control unit;

The control unit of each protection circuit performs an AND operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the single-chip microcomputer, and outputs the control level to the corresponding relay;

The relays of each protection circuit control the on-off of the circuit where the corresponding power module is located based on the control level output by the corresponding control unit.

Further, the current comparison unit of each protection circuit compares the received current sampling value with the preset current setting value to obtain a current comparison signal and send it to the corresponding control unit, including:

The current comparison unit of each protection circuit obtains the current setting value in advance;

The current comparison unit of each protection circuit receives the current sampling value sent by the corresponding current detection unit, compares the received current sampling value with the current setting value, and outputs a current comparison signal to the control unit.

Further, the current comparison unit of each protection circuit receives the current sampling value sent by the corresponding current detection unit, compares the received current sampling value with the current setting value, and outputs the current comparison signal to the control unit, including:

Under normal working conditions, the current sampling value is less than the current setting value, and the current comparison unit outputs a high level to the control unit; when the circuit is short-circuited, the current sampling value is greater than the current setting value, and the current comparison unit outputs a low level to the control unit .

Further, the control unit of each protection circuit performs an AND operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the single-chip microcomputer, and outputs the control level to the corresponding relay, including:

When no over-current situation occurs, the current comparison unit outputs a high level. If the relay is required to be turned on, the single-chip microcomputer outputs a high level, and the control unit performs an AND gate on the high level output by the single-chip microcomputer and the high level output by the current comparison unit. Operation, the control unit outputs a high level to turn on the relay; if it is required to turn off the relay, the single-chip microcomputer outputs a low level, and the control unit performs an AND operation on the low level output by the single-chip microcomputer and the high level output by the current comparison unit, and the control unit Output low level to turn off the relay;

When an over-current situation occurs, the current comparison unit outputs a low level, and the single-chip microcomputer outputs a high level or a low level regardless of the requirement to turn on or off the relay. The low level output by the comparison unit performs an AND gate operation, and the control unit only outputs a low level to turn off the relay.

Further, the method also includes;

The reset circuit controls the on-off of the power supply of the whole system through the reset control signal output by the single-chip microcomputer.

The present invention has the following advantages due to the adoption of the above technical scheme:

1. The present invention realizes the short-circuit protection function entirely through the hardware itself, without the participation of software, can speed up the response time of the short-circuit protection, and at the same time reduce the components of the circuit and save costs.

2. The present invention is provided with several protection circuits, and the operation of short-circuit state latching can be realized through a simple circuit.

3. The present invention is provided with a reset circuit with its own reset function, and it is not necessary to power off the entire system to realize the reset.

4. Since the present invention is provided with several protection circuits, each protection circuit is connected to the corresponding power supply module through the current detection unit, the current comparison unit, the control unit and the relay in sequence, and can protect the short-circuited power supply in the parallel power supply module module, and has no effect on other channels.

In summary, the present invention can be widely applied in the field of protection of parallel power supply modules 6 .

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating a preferred embodiment and are not to be considered as limiting the invention. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the attached picture:

Fig. 1 is a schematic structural diagram of a short-circuit protection system for parallel power supply modules provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a protection circuit provided by an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present invention, and to fully convey the scope of the present invention to those skilled in the art.

It should be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may also be meant to include the plural forms unless the context clearly dictates otherwise. The terms "comprising", "comprising", "containing" and "having" are inclusive and thus indicate the presence of stated features, steps, operations, elements and/or parts but do not exclude the presence or addition of one or Various other features, steps, operations, elements, components, and/or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is specifically indicated. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be referred to as These terms are limited. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

The short-circuit protection system and method for parallel power supply modules provided by the embodiments of the present invention are used for short-circuit protection of the power supply system of parallel power supply modules, and can ensure that the power supply system can still work normally after a certain branch is short-circuited. When a short circuit occurs at the front end of a certain power module, the current detection unit sends the current sampling value to the current comparison unit, and the current comparison unit gives a current comparison signal through comparison, and the control unit controls the relay to disconnect according to the current comparison signal and the control signal output by the microcontroller. This branch, so that other branches can operate normally, so that the entire power system can work normally.

Example 1

As shown in Figure 1, this embodiment provides a short-circuit protection system for parallel power supply modules, including a single-chip microcomputer and several protection circuits 1, wherein each protection circuit 1 includes a current detection unit 2, a current comparison unit 3, a control unit 4 and Relay 5.

One end of each current detection unit 2 is respectively connected to the input end of the power system, and the other end of each current detection unit 2 is connected to a certain power supply module in the power system through the corresponding current comparison unit 3, control unit 4 and relay 5 in sequence 6. The single-chip microcomputer is connected to each control unit 4 respectively.

The single-chip microcomputer is used to output control signals to the control unit 4 according to the control instructions sent by the host computer.

The current detection unit 2 is used to detect the current sampling value of the circuit corresponding to the power module 6 and send it to the current comparison unit 3 .

The current comparison unit 3 is used to compare the current sampling value with the current setting value to obtain a current comparison signal and send it to the control unit 4 .

The control unit 4 is used to perform an AND operation on the current comparison signal and the control signal output by the single-chip microcomputer, and output the control level to the corresponding relay 5 .

The relay 5 is used to control the on-off of the circuit corresponding to the power module 6 based on the control level output by the control unit 4 .

In practical applications, when the entire power supply system is working, the current sampling value detected by the current detection unit 2 of the circuit where each power supply module 6 is located is compared with the preset current setting value of the current comparison unit 3. If the circuit works normally, Then the current sampling value is lower than the current setting value, the control unit 4 outputs the control level to the relay 5 to control the relay 5 to conduct, and the corresponding power module 6 works normally. If the front-end short circuit occurs in the circuit, the current sampling value is greater than the current setting value, the control unit 4 outputs the control level to the relay 5 to control the relay 5 to disconnect, thereby disconnecting the circuit and ensuring the normal operation of other circuits.

In a preferred embodiment, the current detection unit 2 selects a module that matches the actual current sampling value, if it is too small, the function cannot be realized, and if it is too large, the accuracy cannot be guaranteed. Specifically, the current detection unit 2 may adopt a Hall effect current sensing chip.

In a preferred embodiment, the control signal output by the single-chip microcomputer is the high and low levels of IO. The host computer outputs control commands to the single-chip microcomputer, and the single-chip microcomputer outputs high level or low level to the control unit 4 according to the control command of the host computer. When it is turned on, it outputs high level, and when it is turned off, it outputs low level. In the current comparison unit 3, the current sampling value is compared with the current preset value, and a current comparison signal is output, that is, a high level or a low level. The control unit 4 performs an AND calculation on the control signal output by the microcontroller and the current comparison signal output by the current comparison unit 3. If the output is high, the relay 5 is turned on, and if the output is low, the relay 5 is turned off.

As shown in FIG. 2 , the present invention schematically selects one of the logical combinations for illustration.

In a preferred embodiment, each current comparison unit 3 includes a comparator 31 and a diode 32, and the comparator 31 is used to output a current comparison signal according to the current sampling value and the current setting value, that is, a high level or a low level , to the control unit 4; the diode 32 is used to ensure that the output voltage of the comparator 31 will not become high when the relay 5 disconnects the circuit where the corresponding power module 6 is located.

In a preferred embodiment, each protection circuit 1 further includes a reset circuit 7, each reset circuit 7 is respectively connected to a single-chip microcomputer, and the reset circuit 7 is used to reset the circuit where the corresponding power module 6 is located. When a reset is required, the reset control signal (that is, the high and low levels of IO) is output to the reset circuit 7 through the single-chip microcomputer, and the reset of the protection function can be realized without restarting the entire power supply system.

In a preferred embodiment, each protection circuit 1 further includes a voltage dividing unit 8, the voltage dividing unit 8 includes a first voltage dividing resistor 81 and a second voltage dividing resistor 82, the first voltage dividing resistor 81 and the second voltage dividing resistor The resistor 82 is used to divide the voltage of the power supply system to a preset voltage according to a certain ratio and send it to the current comparison unit 3. This voltage is the rated value of the short circuit protection.

In a preferred embodiment, in a protection circuit 1, one end of the reset circuit 7 is connected to the input end of the power system, and the other end of the reset circuit 7 is connected in parallel to the first input end of the comparator 31 through the first voltage dividing resistor 81 and one end of the second voltage dividing resistor 82, the second input end of the comparator 31 is connected to the current detection unit 2, the output end of the comparator 31 is connected in parallel to the input end of the control unit 4 and the negative end of the diode 32, and the positive end of the diode 32 and the other end of the second voltage dividing resistor 82 are respectively grounded. The output end of the control unit 4 is connected to the input end of the relay 5 , and the output end of the relay 5 is connected to the corresponding power module 6 .

In a preferred embodiment, the reset circuit 7 adopts a 5V reset circuit.

Example 2

This embodiment provides a short-circuit protection method for parallel-connected power supply modules, including the following steps:

1) In the power supply system, the current detection unit 2 of each protection circuit 1 detects the current sampling value of the circuit where the corresponding power supply module 6 is located, and sends it to the corresponding current comparison unit 3 .

2) The current comparison unit 3 of each protection circuit 1 compares the received current sampling value with the preset current setting value to obtain a current comparison signal and send it to the corresponding control unit 4, specifically:

2.1) The current comparison unit 3 of each protection circuit 1 obtains the current setting value in advance.

2.2) The current comparison unit 3 of each protection circuit 1 receives the current sampling value sent by the corresponding current detection unit 2, compares the received current sampling value with the current setting value, and outputs a current comparison signal to the control unit 4.

Specifically, under normal working conditions, the current sampling value is less than the current setting value, and the current comparison unit 3 outputs a high level to the control unit 4; when the circuit is short-circuited, the current sampling value is greater than the current setting value, and the current comparison unit 3 outputs Low level to control unit 4.

3) The control unit 4 of each protection circuit 1 performs an AND operation on the current comparison signal output by the corresponding current comparison unit 3 and the control signal output by the single-chip microcomputer, and outputs the control level to the corresponding relay 5 .

Specifically, the control signal output by the single-chip microcomputer is determined by the host computer.

Specifically, when no overcurrent situation occurs, the current comparison unit 3 outputs a high level, and if the relay 5 is required to be turned on, the host computer sends a control command, the single-chip microcomputer outputs a high level, and the control unit 4 outputs a high level to the single-chip microcomputer. Perform an AND gate operation with the high level output by the current comparison unit 3 , and the control unit 4 outputs a high level to turn on the relay 5 . If it is required to turn off the relay 5, then the upper computer sends a control command, the single-chip microcomputer outputs a low level, and the control unit 4 performs an AND operation on the low level output by the single-chip microcomputer and the high level output by the current comparison unit 3, and the control unit 4 outputs a low level Level off relay 5.

Specifically, when an over-current situation occurs, the current comparison unit 3 outputs a low level, then no matter whether the relay 5 is required to be turned on or off, the host computer sends a control command, and the single-chip microcomputer outputs a high level or a low level, and the control unit 4 pairs The high level or low level output by the single chip microcomputer and the low level output by the current comparison unit 3 perform an AND gate operation, and the control unit 4 can only output a low level to turn off the relay 5 . At this time, the current decreases, and the current sampling value will drop, and the comparator 31 of the current comparison unit 3 generates a tube drop voltage of about 0.7V at the first input terminal through the diode 32, so as to ensure that the output voltage of the comparator 31 will not become high. Still low level, and then guarantee the disconnection of relay 5.

4) The relay 5 of each protection circuit 1 is based on the control level output by the corresponding control unit 4 to control the on-off of the circuit where the corresponding power module 6 is located.

5) The voltage dividing unit 8 divides 5V into a preset voltage according to a certain ratio and sends it to the current comparison unit 3, and the voltage can calculate the current value of the short circuit protection according to a certain conversion ratio.

6) The reset circuit 7 controls the on-off of the 5V power supply of the entire system through the reset control signal output by the single-chip microcomputer, that is, the IO level.

Specifically, under normal circumstances, the reset control signal output by the single-chip microcomputer is IO high level, and the whole system works normally. When a reset is required, the IO level is pulled down to disconnect the 5V power supply, and the IO level is pulled up again, the 5V power supply is restored, and the whole system is reset to the state just powered on, and the relay 5 is disconnected at this time.

The above-mentioned embodiments are only used to illustrate the present invention, wherein the structure, connection mode and manufacturing process of each component can be changed to some extent, and any equivalent transformation and improvement carried out on the basis of the technical solution of the present invention should not excluded from the protection scope of the present invention.

Claims (10)

1. A short-circuit protection system for parallel power supply modules is characterized by comprising a single chip microcomputer and a plurality of protection circuits, wherein each protection circuit corresponds to a certain power supply module in a power supply system and comprises a current detection unit, a current comparison unit, a control unit and a relay;

the single chip microcomputer is used for outputting a control signal to each control unit according to the requirement of switching on or switching off the relay;

the current detection unit is used for detecting a current sampling value corresponding to a circuit where the power supply module is located;

the current comparison unit is used for comparing a current sampling value detected by the corresponding current detection unit with a current set value to obtain a current comparison signal;

the control unit is used for performing AND operation on the current comparison signal and the control signal output by the singlechip and outputting a control level;

the relay is used for controlling the on-off of a circuit corresponding to the power supply module based on the control level output by the control unit.

2. The system of claim 1, wherein each of the protection circuits further comprises a voltage divider for dividing a voltage of the power system to a predetermined voltage according to a certain ratio and sending the divided voltage to the current comparator.

3. The parallel power module short-circuit protection system of claim 2, wherein each protection circuit further comprises a reset circuit, each reset circuit is respectively connected with the single chip microcomputer, and the reset circuit is used for resetting a circuit corresponding to the power module.

4. The system of claim 3, wherein each of the current comparing units comprises a comparator and a diode, the comparator is configured to output a current comparing signal to the control unit according to a current sampling value and a current setting value, and the diode is configured to ensure that an output voltage of the comparator does not become high when the relay disconnects a circuit corresponding to the power module.

5. The short-circuit protection system of claim 4, wherein in one of the protection circuits, one end of the reset circuit is connected to an input terminal of a power system, the other end of the reset circuit is connected in parallel to a first input terminal of the comparator and one end of a second voltage-dividing resistor of the voltage-dividing unit through a first voltage-dividing resistor of the voltage-dividing unit, a second input terminal of the comparator is connected to the current detection unit, an output terminal of the comparator is connected in parallel to an input terminal of the control unit and a negative terminal of the diode, and a positive terminal of the diode and the other end of the second voltage-dividing resistor are respectively grounded; the output end of the control unit is connected with the input end of the relay, and the output end of the relay is connected with the power supply module correspondingly.

6. A short-circuit protection method for parallel power supply modules is characterized by comprising the following steps:

in the power supply system, a current detection unit of each protection circuit detects a current sampling value of a circuit where a corresponding power supply module is located and sends the current sampling value to a corresponding current comparison unit;

the current comparison unit of each protection circuit compares the received current sampling value with a preset current set value to obtain a current comparison signal and sends the current comparison signal to the corresponding control unit;

the control unit of each protection circuit performs AND operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the single chip microcomputer, and outputs a control level to the corresponding relay;

and the relay of each protection circuit controls the on-off of the circuit where the corresponding power supply module is based on the control level output by the corresponding control unit.

7. The method as claimed in claim 6, wherein the step of comparing the received current sampling value with the preset current setting value by the current comparing unit of each protection circuit to obtain a current comparison signal, and sending the current comparison signal to the corresponding control unit comprises the steps of:

a current comparison unit of each protection circuit obtains a current set value in advance;

the current comparison unit of each protection circuit receives the current sampling value sent by the corresponding current detection unit, compares the received current sampling value with the current set value, and outputs a current comparison signal to the control unit.

8. The method according to claim 7, wherein the step of receiving the current sampling value sent by the corresponding current detecting unit by the current comparing unit of each protection circuit, comparing the received current sampling value with the current setting value, and outputting the current comparing signal to the control unit comprises:

under the normal working condition, the current sampling value is smaller than the current set value, and the current comparison unit outputs a high level to the control unit; when the circuit is in short circuit, the current sampling value is larger than the current set value, and the current comparison unit outputs a low level to the control unit.

9. The short-circuit protection method of the parallel power supply modules according to claim 8, wherein the control unit of each protection circuit performs and operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the single chip microcomputer, and outputs a control level to the corresponding relay, and the method comprises:

when no overcurrent condition occurs, the current comparison unit outputs a high level, if the relay is required to be switched on, the single chip microcomputer outputs the high level, the control unit performs AND gate operation on the high level output by the single chip microcomputer and the high level output by the current comparison unit, and the control unit outputs the high level to switch on the relay; if the relay is required to be turned off, the single chip microcomputer outputs a low level, the control unit performs AND gate operation on the low level output by the single chip microcomputer and the high level output by the current comparison unit, and the control unit outputs a low level to turn off the relay;

when an overcurrent condition occurs, the current comparison unit outputs a low level, the single chip microcomputer outputs a high level or a low level no matter the relay is required to be switched on and switched off, the control unit performs AND gate operation on the high level or the low level output by the single chip microcomputer and the low level output by the current comparison unit, and the control unit only outputs the low level to switch off the relay.

10. The method of claim 6, further comprising;

the reset circuit controls the on-off of the power supply of the whole system through a reset control signal output by the singlechip.

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