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

Abstract

The application relates to a short-circuit protection system and method for parallel power modules, characterized by comprising a single-chip microcomputer and a plurality of protection circuits, wherein each protection circuit corresponds to a power module in a power supply system, and each protection circuit 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 turning on or turning off the relay; the current detection unit is used for detecting a current sampling value of a circuit in which the corresponding power module is located; the current comparison unit is used for comparing the current sampling value detected by the corresponding current detection unit with a current setting 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 single-chip microcomputer, and outputting a control level; and the relay is used for controlling the on-off of the circuit in which the corresponding power module is located based on the control level output by the control unit, and the application can be widely applied in the field of parallel power module protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of parallel power module protection, and particularly relates to a parallel power module short circuit protection system and method. BACKGROUND

[0002] At present, the power of a single power module cannot be very large, so when a power system has a large power demand, several power modules are usually connected in parallel to increase the power output. However, if a short circuit occurs at the input end of a power module in the parallel output process, the input end of the entire power system will be short-circuited, resulting in failure of the entire power system. To prevent this from happening, a short circuit protection function needs to be added to the input end of the power system.

[0003] However, the short circuit protection method in the prior art has a slow response speed, and many additional devices such as micro control units and latch devices need to be added, which is high in cost and cannot guarantee rapid disconnection of the fault branch, and cannot meet the parallel module short circuit protection requirements of the power system. SUMMARY

[0004] To solve the above problems, the present application aims to provide a parallel power module short circuit protection system and method which is low in cost and can rapidly disconnect the fault branch.

[0005] To achieve the above-mentioned purposes, the present application adopts the following technical solutions: on the one hand, a parallel power module short circuit protection system is provided, comprising a single-chip microcomputer and a plurality of protection circuits, wherein each protection circuit corresponds to a power module in the power system, and each protection circuit comprises a current detection unit, a current comparison unit, a control unit and a relay;

[0006] The single-chip microcomputer is used to output a control signal to each control unit according to the requirement of turning on or turning off the relay;

[0007] The current detection unit is used to detect the current sampling value of the circuit in which the power module is located;

[0008] The current comparison unit is used to compare the current sampling value detected by the current detection unit with a current set value to obtain a current comparison signal;

[0009] The control unit is used to perform AND operation on the current comparison signal and the control signal output by the single-chip microcomputer, and output a control level;

[0010] The relay is used to control the on-off of the circuit in which the power module is located based on the control level output by the control unit.

[0011] Further, each of the protection circuits further comprises a voltage dividing unit for dividing the voltage of the power supply system by a certain ratio to a preset voltage and sending to the current comparison unit.

[0012] Further, each of the protection circuits further comprises a reset circuit, each of the reset circuits being connected to the single-chip microcomputer, and the reset circuit being used for resetting the circuit in which the power supply module is located.

[0013] Further, each of the current comparison units comprises a comparator and a diode, the comparator being used for outputting a current comparison signal to the control unit according to the current sampling value and the current setting value, and the diode being used for ensuring that the output voltage of the comparator will not be high when the relay disconnects the circuit in which the power supply module is located.

[0014] Further, in one of the protection circuits, one end of the reset circuit is connected to the input end of the power supply system, the other end of the reset circuit is connected in parallel to the first input end of the comparator and one end of the second voltage dividing resistor in the voltage dividing unit through the first voltage dividing resistor in the voltage dividing unit, the second input end of the comparator is connected to the current detection unit, the output end of the comparator is connected in parallel to the input end of the control unit and the negative end of the diode, the positive end of the diode and the other end of the second voltage dividing resistor are grounded respectively, the output end of the control unit is connected to the input end of the relay, and the output end of the relay is connected to the power supply module.

[0015] On the other hand, a parallel power supply module short circuit protection method is provided, comprising:

[0016] In the power supply system, the current detection unit of each of the protection circuits detects the current sampling value of the circuit in which the power supply module is located and sends to the corresponding current comparison unit.

[0017] The current comparison unit of each of the protection circuits compares the received current sampling value with the pre-set current setting value, obtains a current comparison signal and sends to the corresponding control unit.

[0018] The control unit of each of the protection circuits 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.

[0019] The relay of each of the protection circuits controls the on-off of the circuit in which the power supply module is located based on the control level output by the corresponding control unit.

[0020] Further, the current comparison unit of each of the protection circuits compares the received current sampling value with the pre-set current setting value, obtains a current comparison signal and sends to the corresponding control unit, comprising:

[0021] The current comparison unit of each protection circuit obtains a current setting value in advance;

[0022] 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.

[0023] 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 a current comparison signal to the control unit, comprising:

[0024] Under normal operating 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.

[0025] Further, 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, comprising:

[0026] When no overcurrent condition occurs, the current comparison unit outputs a high level, if it is required to turn on the relay, the single-chip microcomputer outputs a 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 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, 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.

[0027] When an overcurrent condition occurs, the current comparison unit outputs a low level, then no matter whether it is required to turn on or turn off the relay, the single-chip microcomputer outputs a high level or a low level, 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 a low level to turn off the relay.

[0028] Further, the method further comprises:

[0029] The reset circuit controls the on-off of the power supply of the entire system through the reset control signal output by the single-chip microcomputer.

[0030] The present application has the following advantages due to the above technical solutions:

[0031] 1. The short-circuit protection function of the present application is realized entirely by hardware itself, without the participation of software, which can accelerate the response time of short-circuit protection, reduce the components of the circuit, and save costs.

[0032] 2、 The application is provided with several protection circuits, and short circuit state latching operation can be realized through simple circuit.

[0033] 3、 The application is provided with a reset circuit, and reset function is self-contained, and reset can be realized without power-off of the whole system.

[0034] 4、 The application is provided with several protection circuits, each protection circuit is connected with corresponding power module through current detection unit, current comparison unit, control unit and relay in sequence, and the power module with short circuit can be protected in parallel power module, and other power modules are not affected.

[0035] In summary, the application can be widely applied in parallel power module 6 protection field. BRIEF DESCRIPTION OF DRAWINGS

[0036] 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 embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Throughout the drawings, same reference numerals are used to represent same or similar parts. In the drawings:

[0037] Figure 1 is a structure schematic view of parallel power module short circuit protection system provided by an embodiment of the application;

[0038] Figure 2 is a structure schematic view of a certain protection circuit provided by an embodiment of the application. DETAILED DESCRIPTION

[0039] Exemplary embodiments of the present application will be described hereinafter with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thoroughly and completely understood, and so that the scope of the present application will be fully conveyed to those skilled in the art.

[0040] It is to 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" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0041] Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to differentiate 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 example embodiments.

[0042] The parallel power module short circuit protection system and method provided by the embodiment of the present application is used for short circuit protection of a power supply system of parallel power modules, and can ensure that the power supply system can work normally after a certain branch short circuits. When a short circuit occurs at the front end of a certain power module, the current detection unit sends a current sampling value to the current comparison unit, the current comparison unit gives a current comparison signal by comparison, and the control unit controls the relay to disconnect the branch according to the current comparison signal and a control signal output by the single-chip microcomputer, so that the other branches can work normally, and the entire power supply system can work normally.

[0043] Embodiment 1

[0044] As shown in Figure 1 The embodiment provides a parallel power module short circuit protection system, which comprises a single-chip microcomputer and a plurality of protection circuits 1. Each protection circuit 1 comprises a current detection unit 2, a current comparison unit 3, a control unit 4 and a relay 5.

[0045] One end of each current detection unit 2 is connected to the input end of the power supply system, and the other end of each current detection unit 2 is connected to a certain power module 6 in the power supply system in turn through the corresponding current comparison unit 3, the control unit 4 and the relay 5, and the single-chip microcomputer is connected to each control unit 4.

[0046] The single-chip microcomputer is configured to output a control signal to the control unit 4 according to a control instruction sent by the host computer.

[0047] The current detection unit 2 is configured to detect a current sampling value of a circuit in which the power module 6 is located and send the current sampling value to the current comparison unit 3.

[0048] The current comparison unit 3 is configured to compare the current sampling value with a current setting value, obtain a current comparison signal, and send the current comparison signal to the control unit 4.

[0049] The control unit 4 is configured to perform an AND operation on the current comparison signal and a control signal output by the single-chip microcomputer, and output a control level to the corresponding relay 5.

[0050] The relay 5 is configured to control the on-off of the circuit in which the power module 6 is located based on the control level output by the control unit 4.

[0051] In actual application, when the entire power supply system is working, the current sampling value detected by the current detection unit 2 of the circuit in which the power module 6 is located is compared with the current setting value pre-set by the current comparison unit 3. If the circuit is working normally, 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 be turned on, and the corresponding power module 6 works normally. If a 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 be turned off, so that the circuit is disconnected, and the normal operation of other circuits is ensured.

[0052] In a preferred embodiment, the current detection unit 2 selects a module that matches the actual current sampling value. If the module is too small, the function cannot be realized, and if the module is too large, the accuracy cannot be ensured. Specifically, the current detection unit 2 can adopt a current sensing chip based on the Hall effect.

[0053] In a preferred embodiment, the control signal output by the single-chip microcomputer is the high-low level of IO. The host computer outputs a control instruction to the single-chip microcomputer, the single-chip microcomputer outputs a high level or a low level to the control unit 4 according to the control instruction of the host computer, the on-off is turned on, and the output high level is turned off. In the current comparison unit 3, the current sampling value and the current preset value are compared, and a current comparison signal, i.e., a high level or a low level, is output. The control unit 4 performs an AND gate calculation on the control signal output by the single-chip microcomputer and the current comparison signal output by the current comparison unit 3. If a high level is output, the relay 5 is turned on, and if a low level is output, the relay 5 is turned off.

[0054] As shown in FIG. 1, Figure 2 the present application schematically selects one kind of logic combination for illustration.

[0055] In a preferred embodiment, each current comparison unit 3 comprises a comparator 31 for outputting a current comparison signal, i.e. high level or low level, to the control unit 4 according to the current sampling value and the current setting value, and a diode 32 for ensuring that the output voltage of the comparator 31 will not be high when the relay 5 disconnects the circuit where the corresponding power module 6 is located.

[0056] In a preferred embodiment, each protection circuit 1 further comprises a reset circuit 7 connected to the single-chip microcomputer, which is used to reset the circuit where the corresponding power module 6 is located. When reset is needed, the single-chip microcomputer outputs a reset control signal (i.e. high or low level of IO) to the reset circuit 7, so that the reset of the protection function can be realized without restarting the entire power supply system.

[0057] In a preferred embodiment, each protection circuit 1 further comprises a voltage dividing unit 8 comprising a first voltage dividing resistor 81 and a second voltage dividing resistor 82, which are used to divide the voltage of the power supply system to a preset voltage in a certain proportion and send it to the current comparison unit 3. This voltage is the rated value of short-circuit protection.

[0058] In a preferred embodiment, in one protection circuit 1, one end of the reset circuit 7 is connected to the input end of the power supply system, the other end of the reset circuit 7 is connected in parallel to the first input end of the comparator 31 and one end of the second voltage dividing resistor 82 through the first voltage dividing resistor 81, 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, the positive end of the diode 32 and the other end of the second voltage dividing resistor 82 are grounded respectively. 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.

[0059] In a preferred embodiment, the reset circuit 7 adopts a 5V reset circuit.

[0060] Embodiment 2

[0061] The embodiment provides a short-circuit protection method for parallel power modules, which comprises the following steps:

[0062] 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 module 6 is located and sends it to the corresponding current comparison unit 3.

[0063] 2) The current comparison unit 3 of each protection circuit 1 compares the received current sampling value with the pre-set current setting value, obtains a current comparison signal and sends it to the corresponding control unit 4, which is specifically:

[0064] 2.1) The current comparison unit 3 of each protection circuit 1 obtains a current setting value in advance.

[0065] 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.

[0066] 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 a low level to the control unit 4.

[0067] 3) The control unit 4 of each protection circuit 1 performs 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 a control level to the corresponding relay 5.

[0068] Specifically, the control signal output by the single-chip microcomputer is determined by the upper computer.

[0069] Specifically, when no overcurrent condition occurs, the current comparison unit 3 outputs a high level, if it is required to turn on the relay 5, the upper computer sends a control instruction, the single-chip microcomputer outputs a high level, the control unit 4 performs AND operation on the high 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 high level to turn on the relay 5. If it is required to turn off the relay 5, the upper computer sends a control instruction, the single-chip microcomputer outputs a low level, the control unit 4 performs 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 to turn off the relay 5.

[0070] Specifically, when an overcurrent condition occurs, the current comparison unit 3 outputs a low level, regardless of whether it is required to turn on or turn off the relay 5, the upper computer sends a control instruction, the single-chip microcomputer outputs a high level or a low level, the control unit 4 performs AND operation on the high level or low level output by the single-chip microcomputer and the low level output by the current comparison unit 3, 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 decreases, the comparator 31 of the current comparison unit 3 generates a voltage drop of about 0.7V at the first input end through the diode 32, which ensures that the output voltage of the comparator 31 does not become high and remains low, thereby ensuring that the relay 5 is disconnected.

[0071] 4) The relay 5 of each protection circuit 1 controls the on-off of the circuit where the corresponding power module 6 is located based on the control level output by the corresponding control unit 4.

[0072] 5) The voltage dividing unit 8 divides the 5V voltage into a preset voltage in 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.

[0073] 6) The reset circuit 7 controls the on-off of the 5V power supply of the whole system through the reset control signal, i.e. IO level, output by the single-chip microcomputer.

[0074] 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 resetting is needed, the IO level is pulled low, the 5V power supply is disconnected, the IO level is pulled high again, the 5V power supply is restored, and the whole system is reset to the state just after power-on, at this time the relay 5 is disconnected.

[0075] The above embodiments are only used for illustrating the present application, wherein the structure, connection mode and manufacturing process of each component can be changed, and any equivalent transformation and improvement on the basis of the technical scheme of the present application should not be excluded from the protection scope of the present application.

Claims

1. A short-circuit protection system for parallel power supply modules, characterized in that, It includes a microcontroller and several protection circuits, wherein each of the protection circuits corresponds to a power 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 microcontroller is used to output control signals to each of the control units according to the requirements of turning the relay on or off; The current detection unit is used to detect the current sampling value of the circuit corresponding to the power module. The current comparison unit is used to compare the current sample 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 a control level. The relay is used to control the on / off state of the circuit corresponding to the power module based on the control level output by the control unit; Each of the protection circuits further includes a voltage divider unit, 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; Each of the protection circuits further includes a reset circuit, and each reset circuit is connected to the microcontroller. The reset circuit is used to reset the circuit corresponding to the power module.

2. The short-circuit protection system for a parallel power supply module as described in claim 1, characterized in that, Each current comparison unit includes a comparator and a diode. The comparator is used to output a current comparison signal to the control unit based on the current sample value and the current set value. The diode is used to ensure that the output voltage of the comparator does not increase when the relay disconnects the circuit corresponding to the power module.

3. The short-circuit protection system for a parallel power supply module as described in claim 2, characterized in that, In one of the protection circuits, one end of the reset circuit is connected to the input terminal of the power supply system, and the other end of the reset circuit is connected in parallel to the first input terminal of the comparator and one end of the second voltage divider resistor in the voltage divider unit through the first voltage divider resistor in the voltage divider 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 input terminal of the control unit and the negative terminal of the diode. The positive terminal of the diode and the other end of the second voltage divider resistor are respectively grounded. The output terminal of the control unit is connected to the input terminal of the relay, and the output terminal of the relay is connected to the corresponding power supply module.

4. A method for short-circuit protection of a parallel power module based on the parallel power module short-circuit protection system according to any one of claims 1 to 3, characterized in that, include: 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 module is located and sends it to the corresponding current comparison unit. Each protection circuit's current comparison unit compares the received current sample value with the preset current setting value to obtain a current comparison signal and sends it to the corresponding control unit. Each protection circuit's control unit performs an AND operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the microcontroller, and outputs a control level to the corresponding relay. Each protection circuit's relay controls the on / off state of the circuit containing the corresponding power module based on the control level output by the corresponding control unit.

5. The short-circuit protection method for parallel power supply modules as described in claim 4, characterized in that, Each protection circuit's current comparison unit compares the received current sample value with a preset current setting value to obtain a current comparison signal, which is then sent to the corresponding control unit, including: Each protection circuit's current comparison unit has a pre-set current value. Each protection circuit's current comparison unit 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.

6. The short-circuit protection method for parallel power supply modules as described in claim 5, characterized in that, Each protection circuit's current comparison unit receives a 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, including: Under normal operating conditions, when the current sample value is less than the current set value, the current comparison unit outputs a high level to the control unit; when the circuit is short-circuited, when the current sample value is greater than the current set value, the current comparison unit outputs a low level to the control unit.

7. The short-circuit protection method for parallel power supply modules as described in claim 6, characterized in that, The control unit of each protection circuit performs a bitwise AND operation on the current comparison signal output by the corresponding current comparison unit and the control signal output by the microcontroller, and outputs a control level to the corresponding relay, including: When no overcurrent occurs, the current comparison unit outputs a high level. If the relay needs to be turned on, the microcontroller outputs a high level, and the control unit performs an AND operation between the high level output by the microcontroller and the high level output by the current comparison unit. The control unit then outputs a high level to turn on the relay. If the relay needs to be turned off, the microcontroller outputs a low level, and the control unit performs an AND operation between the low level output by the microcontroller and the high level output by the current comparison unit. The control unit then outputs a low level to turn off the relay. When an overcurrent occurs, the current comparison unit outputs a low level. Regardless of whether the relay needs to be turned on or off, the microcontroller outputs a high or low level. The control unit performs an AND operation between the high or low level output by the microcontroller and the low level output by the current comparison unit. The control unit then outputs a low level to turn off the relay.

8. The short-circuit protection method for parallel power supply modules as described in claim 4, characterized in that, The method also includes; The reset circuit controls the power supply to the entire system by using the reset control signal output by the microcontroller.

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