Ground fault protection circuit, device and method

Abstract

The application discloses a ground fault protection circuit, device and method, and relates to the technical field of automatic control. The circuit comprises a micro control unit, N loads, a detection module and a protection module corresponding to each load, and (N-1) multiplexing modules; the protection module is used for shutting down the load connected to the protection module when a ground fault occurs at the ground end connected to the corresponding detection module; the detection module is used for inputting a detection signal to the micro control unit, and the detection signal is used for indicating whether a ground fault occurs at the ground end connected to the detection module; and the micro control unit is used for controlling to reduce the total power of two loads and controlling the multiplexing module to be turned on when a ground fault occurs at the ground end connected to one detection module or a ground fault occurs at the ground end connected to other detection modules. The application improves the stability of power supply of the vehicle-mounted electronic control system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automatic control, in particular to a ground fault protection circuit, device and method. BACKGROUND

[0002] At present, with the development of automatic control technology, many traditional mechanical components are realized by electronic control, and a typical case is the vehicle-mounted electronic control system of a car. The vehicle-mounted electronic control system is generally composed of a storage battery, a connector, a microcontroller unit (MCU) and a plurality of loads. For example, as shown in FIG. 1, the positive electrode of the storage battery is connected to the power input end Power1 through the connector to supply power to the load L1, and the power input end Power2 supplies power to the load L2, and then flows back to the negative electrode of the power supply through the ground end GND1 and the ground end GND2 respectively, forming a loop. For the vehicle-mounted electronic control system, it is particularly important to ensure the stability of the storage battery power supply. Figure 1

[0003] In the prior art, GND1 and GND2 are designed to be short-circuit connected, so that when a ground fault (the connection between the ground end and the negative electrode of the storage battery is disconnected) occurs at any one of the ground ends of the connector, the load in the fault loop can be ensured to run through the connection with the other ground end, thereby ensuring the stability of the storage battery power supply. However, this will cause the drive current flowing through the other ground end to exceed the maximum value of its designed overcurrent capacity, thereby causing the ground end to burn out quickly, affecting the normal operation of the vehicle-mounted electronic control system. SUMMARY

[0004] The present application provides a ground fault protection circuit, device and method, which can solve the problem that after a ground fault occurs in any one of the two ground ends connected in parallel, the other ground end will quickly overcurrent and burn out, thereby affecting the normal operation of the vehicle-mounted electronic control system.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a ground fault protection circuit, which comprises a microcontroller unit, N loads, a detection module and a protection module corresponding to each load, and (N-1) multiplexing modules, N being a positive integer greater than 1;

[0007] Each detection module is connected to one power input end of the connector, and is also connected to two ground ends of the connector respectively, and is connected to the microcontroller unit, and one detection module is also connected to the input end and the output end of one load respectively;

[0008] ​Each protection module is connected with a corresponding detection module and an enable end of a load connected with the detection module;

[0009] Each multiplexing module is connected with one detection module and other detection modules, and is connected with a micro control unit, the other detection modules being any detection module except the one detection module;

[0010] The protection module is configured to turn off a load connected with the protection module when a ground fault occurs at a ground end connected with a corresponding detection module.

[0011] The detection module is configured to input a detection signal to the micro control unit, the detection signal being used to indicate whether a ground fault occurs at a ground end connected with the detection module.

[0012] The micro control unit is configured to control to reduce total power of two loads and control a multiplexing module to be turned on when a ground fault occurs at a ground end connected with one detection module or a ground fault occurs at a ground end connected with other detection modules, the two loads being loads connected with the one detection module and the other detection module respectively.

[0013] In a possible implementation, the detection module includes a first resistor, a second resistor and a third resistor; one end of the first resistor is connected with one power input end of the connector, the other end of the first resistor is connected with the micro control unit and one end of the second resistor, the other end of the second resistor is connected with one ground end of the connector and one end of the third resistor, the other end of the third resistor is connected with another ground end of the connector.

[0014] In a possible implementation, the protection module includes a first protection submodule and a second protection submodule; the first protection submodule is connected with a corresponding detection module of the protection module and the second protection submodule; the second protection submodule is further connected with an enable end of a load connected with the detection module; the first protection submodule is configured to output a first voltage signal and output a second voltage signal when a ground fault occurs at a ground end connected with the corresponding detection module; and the second protection submodule is configured to input a disable signal to the load according to the first voltage signal and the second voltage signal, so as to turn off the load.

[0015] In a possible implementation, the first protection submodule includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first diode and a second diode; one end of the fourth resistor is connected to the corresponding detection module of the protection module, the other end of the fourth resistor is connected to the second protection submodule, and is connected to one end of the fifth resistor, the other end of the fifth resistor is connected to the anode of the first diode and the anode of the second diode, the cathode of the first diode is connected to the corresponding detection module of the protection module and one end of the sixth resistor, the other end of the sixth resistor is connected to the corresponding detection module of the protection module and the cathode of the second diode, and is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to the second protection submodule and one end of the eighth resistor, the other end of the eighth resistor is connected to the corresponding detection module of the protection module.

[0016] In a possible implementation, the second protection submodule includes an operational amplifier; the non-inverting input end of the operational amplifier is connected to the first protection submodule, the inverting input end of the operational amplifier is connected to the first protection submodule, and the output end of the operational amplifier is connected to the enable end of the load connected to the detection module.

[0017] In a possible implementation, the multiplexing module includes a first switch submodule and a second switch submodule; the first switch submodule is connected to one detection module, connected to other detection modules, connected to the second switch submodule, and connected to the micro control unit; the second switch submodule is also connected to one detection module and connected to other detection modules; the first switch submodule is configured to receive a control signal sent by the micro control unit, and input a conduction voltage signal to the second switch submodule according to the control signal; the second switch submodule is configured to conduct the second switch submodule according to the conduction voltage signal.

[0018] In a possible implementation, the first switch sub-module comprises a ninth resistor, a tenth resistor, an eleventh resistor, a third diode, a fourth diode, a fifth diode, a sixth diode, a first triode, and a second triode, the first triode is an NPN triode, and the second triode is a PNP triode; a positive electrode of the third diode is connected with one detection module, a negative electrode of the third diode is connected with one end of the ninth resistor and one end of the tenth resistor, and is connected with a negative electrode of the fourth diode; a positive electrode of the fourth diode is connected with other detection modules; the other end of the ninth resistor is connected with a collector of the first triode and a base of the second triode; a base of the first triode is connected with a micro control unit, an emitter of the first triode is connected with a positive electrode of the fifth diode, a positive electrode of the sixth diode, and one end of the eleventh resistor; a negative electrode of the fifth diode is connected with one detection module; a negative electrode of the sixth diode is connected with other detection modules; the other end of the eleventh resistor is connected with the second switch sub-module and a collector of the second triode, and an emitter of the second triode is connected with the other end of the tenth resistor.

[0019] In a possible implementation, the second switch sub-module comprises a first field effect tube and a second field effect tube, the first field effect tube is an N-channel field effect tube, and the second field effect tube is an N-channel field effect tube; a drain of the first field effect tube is connected with other detection modules, a gate of the first field effect tube is connected with the first switch sub-module and a gate of the second field effect tube, a source of the first field effect tube is connected with a source of the second field effect tube, and a drain of the second field effect tube is connected with one detection module.

[0020] In a possible implementation, the second switch sub-module comprises a first field effect tube and a second field effect tube, the first field effect tube is an N-channel field effect tube, and the second field effect tube is an N-channel field effect tube; a drain of the first field effect tube is connected with other detection modules, a gate of the first field effect tube is connected with the first switch sub-module and a gate of the second field effect tube, a source of the first field effect tube is connected with a source of the second field effect tube, and a drain of the second field effect tube is connected with one detection module.

[0021] The N positive poles of the storage battery are one-to-one plugged with the N power input ends of the connector, and the N negative poles of the storage battery are one-to-one plugged with the N ground ends of the connector.

[0022] In a possible implementation, the second switch sub-module comprises a first field effect tube and a second field effect tube, the first field effect tube is an N-channel field effect tube, and the second field effect tube is an N-channel field effect tube; a drain of the first field effect tube is connected with other detection modules, a gate of the first field effect tube is connected with the first switch sub-module and a gate of the second field effect tube, a source of the first field effect tube is connected with a source of the second field effect tube, and a drain of the second field effect tube is connected with one detection module.

[0023] The N positive poles of the storage battery are one-to-one plugged with the N power input ends of the connector, and the N negative poles of the storage battery are one-to-one plugged with the N ground ends of the connector.

[0024] In a fourth aspect, the present application provides a ground fault protection method applied to the ground fault protection circuit of the first aspect and any possible implementation manner of the first aspect, the ground fault protection circuit comprising a micro control unit, N loads, a detection module and a protection module corresponding to each load, and (N-1) multiplexing modules, N being a positive integer greater than 1.

[0025] The ground fault protection method comprises:

[0026] The protection module turns off the load connected to the protection module when a ground fault occurs at the ground end connected to the corresponding detection module.

[0027] The detection module inputs a detection signal to the micro control unit, the detection signal being used to indicate whether a ground fault occurs at the ground end connected to the detection module.

[0028] The micro control unit controls to reduce the total power of two loads and controls the multiplexing module to be turned on when a ground fault occurs at the ground end connected to one detection module or a ground fault occurs at the ground end connected to another detection module, the two loads being the loads connected to one detection module and another detection module respectively.

[0029] The application provides a ground fault protection circuit, which comprises a micro control unit, N loads, a detection module and a protection module corresponding to each load, and (N-1) multiplexing modules, wherein N is a positive integer greater than 1; each detection module is connected with one power input end of a connector, is connected with two ground ends of the connector respectively, and is connected with the micro control unit; one detection module is further connected with the input end and the output end of one load; each protection module is connected with the corresponding detection module and the enable end of the load connected with the detection module; each multiplexing module is connected with one detection module and other detection modules, and is connected with the micro control unit; the other detection modules are any detection module except one detection module; the protection module is used for closing the load connected with the protection module when a ground fault occurs in the ground end connected with the corresponding detection module; the detection module is used for inputting a detection signal to the micro control unit, wherein the detection signal is used for indicating whether a ground fault occurs in the ground end connected with the detection module; and the micro control unit is used for controlling to reduce the total power of two loads and controlling the multiplexing module to be turned on when a ground fault occurs in the ground end connected with one detection module or a ground fault occurs in the ground end connected with other detection modules, wherein the two loads are the loads connected with one detection module and other detection modules respectively. In this way, the ground fault protection circuit can timely cut off the load circuit with a ground fault, can identify the load circuit with a ground fault through the detection module and the MCU, and can control the multiplexing module to be turned on through the MCU to reduce the total power of two loads, thereby solving the problem that when a ground fault occurs in any one of the two ground ends after parallel connection, the other ground end will soon overcurrent and burn out, thereby affecting the normal operation of the vehicle-mounted electronic control system, and improving the stability of power supply of the vehicle-mounted electronic control system. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 is a circuit structure schematic diagram of a vehicle-mounted electronic control system;

[0031] Figure 2 FIG. 2 is a connection structure schematic diagram of a ground fault protection circuit according to an embodiment of the application;

[0032] Figure 3 FIG. 3 is another connection structure schematic diagram of a ground fault protection circuit according to an embodiment of the application;

[0033] Figure 4 FIG. 4 is a third connection structure schematic diagram of a ground fault protection circuit according to an embodiment of the application;

[0034] Figure 5 FIG. 5 is a fourth connection structure schematic diagram of a ground fault protection circuit according to an embodiment of the application;

[0035] Figure 6A flowchart of a ground fault method provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] Hereinafter, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, step, calculation or other action "based on" or "according to" one or more stated conditions or values can be based on additional conditions or values beyond the stated values in practice.

[0038] In the ground fault protection circuit in the prior art, the current flowing capacity of the wire harness and the power circuit is generally designed according to the driving current of the load, so that Figure 1 For example, the driving current of the load L1 and the load L2 is 20A, and the overcurrent capacity of the power wire harness, the power input end Power1, the power input end Power2, the ground end GND1 and the ground end GND2 is generally designed as 25-30A, and GND1 and GND2 are designed as short-circuit connection, so that the overcurrent capacity of GND1 and GND2 in parallel can reach 50-60A. However, when a single ground end occurs a ground fault, the total driving current of the two loads will exceed the overcurrent capacity of the remaining ground end, resulting in that the remaining ground end is also burned out soon.

[0039] In order to solve the problem that the ground fault circuit can be detected, and after a ground fault occurs in any one of the two ground ends in parallel, the other ground end will be burned out soon, thereby affecting the normal operation of the vehicle-mounted electronic control system, an embodiment of the present application provides a ground fault protection circuit, device and method.

[0040] Taking two loads (the load L1 and the load L2) as an example, based on Figure 1 , Figure 2 A connection structure diagram of a ground fault protection circuit provided by an embodiment of the present application is shown. As Figure 2As shown, the ground fault protection circuit provided by the embodiment of the application comprises an MCU, a load L1, a load L2, a detection module 10 and a protection module 20 corresponding to each load, and a multiplexing module 30. It can be understood that the number of loads is not limited to two, and when the number of loads is N, the number of multiplexing modules 30 is (N-1), wherein N is a positive integer greater than 1. Specifically, the first end of each detection module 10 is used to be connected with a power input end of a connector, the second end and the third end are used to be connected with two ground ends of the connector respectively, the fourth end is connected with a detection end of the MCU, and the first end and the second end of one detection module 10 are further connected with an input end and an output end of one load respectively.

[0041] The first end, the second end and the third end of each protection module 20 are connected with the first end, the second end and the third end of the corresponding detection module 10 respectively, and the fourth end is connected with an enable end EN of the load connected with the detection module 10.

[0042] The first end and the second end of each multiplexing module 30 are connected with the first end and the second end of one detection module 10 respectively, the third end and the fourth end are connected with the first end and the second end of another detection module 10 respectively, and the fifth end is connected with a control end Ctl of the MCU. The other detection module 10 is any detection module except one detection module 10.

[0043] In actual application, the protection module 20 can be used to close the load connected with the protection module 20 when the ground fault occurs in the ground end connected with the second end of the corresponding detection module 10.

[0044] The detection module 10 can be used to input a detection signal to the MCU. The detection signal is used to indicate whether the ground fault occurs in the ground end connected with the second end of the detection module 10.

[0045] The MCU can be used to control to reduce the total power of two loads and control the multiplexing module 30 to be turned on when the ground fault occurs in the ground end connected with the second end of one detection module 10 or the ground fault occurs in the ground end connected with the second end of another detection module 10, so that the second end of one detection module 10 is short-circuited with the second end of another detection module 10, and the two loads are the loads connected with one detection module 10 and another detection module 10 respectively.

[0046] The ground fault protection circuit in this embodiment includes a microcontroller unit, N loads, a detection module and a protection module corresponding to each load, and (N-1) multiplexing modules, where N is a positive integer greater than 1. The first terminal of each detection module is connected to one power input terminal of a connector, the second and third terminals are connected to the two ground terminals of the connector respectively, and the fourth terminal is connected to the detection terminal of the microcontroller unit. The first and second terminals of one detection module are also connected to the input and output terminals of one load, respectively. The first, second, and third terminals of each protection module are connected to the first, second, and third terminals of the corresponding detection modules, respectively, and the fourth terminal is connected to the enable terminal of the load connected to the detection module. The first and second terminals of each multiplexing module are connected to the first and second terminals of one detection module, respectively, and the third and fourth terminals are connected to other detection modules respectively. The first and second terminals of the detection module are connected, and the fifth terminal is connected to the control terminal of the microcontroller. Other detection modules are any detection modules except for one detection module. The protection module is used to shut down the load connected to the protection module when a ground fault occurs at the ground terminal connected to the second terminal of the corresponding detection module. The detection module is used to input a detection signal to the microcontroller, which indicates whether a ground fault has occurred at the ground terminal connected to the second terminal of the detection module. The microcontroller is used to control the reduction of the total power of the two loads and control the multiplexing module to conduct when a ground fault occurs at the ground terminal connected to the second terminal of one detection module or the ground terminal connected to the second terminal of another detection module. This causes the second terminal of one detection module to be short-circuited with the second terminal of the other detection modules, and the two loads are loads connected to one detection module and the other detection module respectively. In this way, the present invention can promptly disconnect the load circuit that has experienced a ground fault through the protection module, and can identify the specific load circuit that has experienced a ground fault through the detection module and MCU. Furthermore, it can reduce the total power of the two loads through MCU control, and then control the multiplexing module to conduct through MCU control. This solves the problem that if one of the two grounding terminals in the parallel connection experiences a ground fault, the other grounding terminal will quickly burn out due to overcurrent, thus affecting the normal operation of the vehicle electronic control system, thereby improving the power supply stability of the vehicle electronic control system.

[0047] Optional, based on Figure 2 , Figure 3 This is a second schematic diagram of the connection structure of the ground fault protection circuit provided in an embodiment of the present invention. (See diagram below.) Figure 3 As shown, the detection module 10 may include a first resistor R1, a second resistor R2, and a third resistor R3. One end of the first resistor R1 is the first terminal of the detection module 10, and the other end of the first resistor R1 is the fourth terminal of the detection module 10 and is connected to one end of the second resistor R2. The other end of the second resistor R2 is the second terminal of the detection module 10 and is connected to one end of the third resistor R3. The other end of the third resistor R3 is the third terminal of the detection module 10.

[0048] In practical application, taking the GND1 disconnection fault detection as an example:

[0049] When the GND1 is connected well, the voltage V detected by the MCU detection end is: gnd1

[0050] V gnd1 = V Power1 *R2 / (R1+R2);

[0051] Wherein, V Power1 is the input voltage of the power input end Power1.

[0052] When the GND1 has a disconnection fault, and the GND2 is normally connected, V gnd1 then becomes:

[0053] V gnd1 = V Power1 *(R2+R3) / (R1+R2+R3)。

[0054] Therefore, the MCU detection end can determine whether the GND1 is open circuit by detecting the voltage change between R1 and R2. The principle of GND2 disconnection fault detection is the same as above, which is not described here. It is worth noting that the third resistor R3 can be a resistor shared between the two detection modules 10.

[0055] In the embodiment, the MCU detection end determines whether the ground end is open circuit by detecting the voltage change between R1 and R2, thereby realizing the detection and identification of the disconnection fault.

[0056] Optionally, based on Figure 3 , Figure 4 Fig. 3 shows a connection structure schematic diagram of a disconnection fault circuit provided by an embodiment of the present application. As shown in the figure, the protection module 20 can include a first protection sub-module 210 and a second protection sub-module 220. Figure 4

[0057] Wherein, the first end of the first protection sub-module 210 is the first end of the protection module 20, the second end is connected with the first end of the second protection sub-module 220, the third end is connected with the second end of the second protection sub-module 220, the fourth end is the second end of the protection module 20, and the fifth end is the third end of the protection module 20; the third end of the second protection sub-module 220 is the fourth end of the protection module 20.

[0058] ​​Specifically, the second end of the first protection submodule 210 is configured to output a first voltage signal, and the third end of the first protection submodule 210 is configured to output a second voltage signal when a ground fault occurs at the second end of the corresponding detection module 10; the third end of the second protection submodule 220 is configured to input an inhibition signal to a load connected to the protection module 20 according to the first voltage signal and the second voltage signal, so as to turn off the load connected to the protection module 20, thereby being able to timely cut off the operation of the load in the circuit of the ground end where the ground fault occurs.

[0059] In a possible implementation, the first protection submodule 210 can include a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1, and a second diode D2; and the second protection submodule 220 can include an operational amplifier U1.

[0060] In the first protection submodule 210, one end of the fourth resistor R4 is the first end of the first protection submodule 210, the other end of the fourth resistor R4 is the second end of the first protection submodule 210, and is connected to one end of the fifth resistor R5; the other end of the fifth resistor R5 is connected to the anode of the first diode D1, and is connected to the anode of the second diode D2; the cathode of the first diode D1 is the fifth end of the first protection submodule 210, and is connected to one end of the sixth resistor R6; the other end of the sixth resistor R6 is the fourth end of the first protection submodule 210, and is connected to the cathode of the second diode D2, and is connected to one end of the seventh resistor R7; the other end of the seventh resistor R7 is the third end of the first protection submodule 210, and is connected to one end of the eighth resistor R8; the other end of the eighth resistor R8 is the first end of the first protection submodule 210. In the second protection submodule 220, the noninverting input terminal of the operational amplifier U1 is the first end of the second protection submodule 220, the inverting input terminal of the operational amplifier U1 is the second end of the second protection submodule 220, and the output terminal of the operational amplifier U1 is the third end of the second protection submodule 220.

[0061] In actual application, the GND1 ground fault protection is taken as an example.

[0062] The input voltage V th-gnd1 of the noninverting input terminal is a ground fault protection detection threshold value, as long as any one of GND1 and GND2 is grounded, the anodes of D1 and D2 are constant at the forward voltage drop of the diode, about 0.7 V, so V th-gnd1 is a constant value, and V th-gnd1 = 0.7 + (V Power1 - 0.7) * R7 / (R6 + R7).

[0063] The input voltage V p-gnd1 of the inverting input terminal is a GND1 ground fault protection activation voltage, when GND1 is connected well, V p-gnd1-normal = V Power1R9 / (R8+R9); when GND1 occurs a ground fault, V p-gnd1-open = V Power1 *(R9+R3) / (R8+R9+R3).

[0064] Adjust the resistance network parameters, V p-gnd1-open >V th-gnd1 >V p-gnd1-normal . In this way, when GND1 is well connected, the non-inverting input voltage V+ of U1 is greater than the inverting input voltage V-, U1 outputs a high voltage, thereby enabling the load L1, and the load L1 can normally operate;When GND1 occurs a ground fault, the non-inverting input voltage V+ of U1 is less than the inverting input voltage V-, U1 outputs a low voltage, the load L1 is disabled, and the load L1 is closed and stopped running. It is worth noting that the sixth resistor R6 in the embodiment can be the third resistor R3 in the above-mentioned embodiment. The ground fault protection module of GND2 has the same principle, which will not be repeated here.

[0065] Optionally, based on Figure 4 , Figure 5 Figure 5 shows a connection structure schematic diagram of the ground fault protection circuit provided by the embodiment of the application. As shown in Figure 5 The multiplexing module 30 includes a first switch submodule 310 and a second switch submodule 320.

[0066] The first end of the first switch submodule 310 is the first end of the multiplexing module 30;The second end of the first switch submodule 310 is the second end of the multiplexing module 30;The third end of the first switch submodule 310 is the third end of the multiplexing module 30;The fourth end of the first switch submodule 310 is the fourth end of the multiplexing module 30;The fifth end of the first switch submodule 310 is the fifth end of the multiplexing module 30;The sixth end of the first switch submodule 310 is connected with the first end of the second switch submodule 320;The second end of the second switch submodule 320 is the second end of the multiplexing module 30, and the third end of the second switch submodule 320 is the fourth end of the multiplexing module 30. Specifically, the first switch submodule 310 can be used to receive the control signal sent by the MCU, and input the conduction voltage signal to the second switch submodule 320 according to the control signal;The second switch submodule 320 can be used to turn on the second end and the third end of the second switch submodule 320 according to the conduction voltage signal.

[0067] In a possible implementation, the first switch submodule 310 can include a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first triode T1, and a second triode T2, the first triode T1 is an NPN type triode, and the second triode T2 is a PNP type triode; and the second switch submodule 320 can include a first field effect tube Q1 and a second field effect tube Q2, both the first field effect tube Q1 and the second field effect tube Q2 are N-channel field effect tubes.

[0068] The positive electrode of the third diode D3 is the first end of the first switch submodule 310, the negative electrode of the third diode D3 is connected with one end of the ninth resistor R9 and one end of the tenth resistor R10, and is connected with the negative electrode of the fourth diode D4; the positive electrode of the fourth diode D4 is the third end of the first switch submodule 310; the other end of the ninth resistor R9 is connected with the collector of the first triode T1, and is connected with the base of the second triode T2; the base of the first triode T1 is the fifth end of the first switch submodule 310, the emitter of the first triode T1 is connected with the positive electrode of the fifth diode D5, and is connected with the positive electrode of the sixth diode D6, and is connected with one end of the eleventh resistor R11; the negative electrode of the fifth diode D5 is the second end of the first switch submodule 310; the negative electrode of the sixth diode D6 is the fourth end of the first switch submodule 310; the other end of the eleventh resistor R11 is the sixth end of the first switch submodule 310, and is connected with the collector of the second triode T2, and the emitter of the second triode T2 is connected with the other end of the tenth resistor R10.

[0069] The drain of the first field effect tube Q1 is the third end of the second switch submodule 320, the gate of the first field effect tube Q1 is the first end of the second switch submodule 320, and is connected with the gate of the second field effect tube Q2, the source of the first field effect tube Q1 is connected with the source of the second field effect tube Q2, and the drain of the second field effect tube Q2 is the second end of the second switch submodule 320.

[0070] In practical application, when GND1 and GND2 are normally grounded, the control signal sent by the control end Ctl of the MCU is a low-voltage signal, T1 is closed, T2 is also closed, Q1 and Q2 are both closed, GND1 and GND2 are isolated and not connected; when a ground fault occurs in one of GND1 and GND2, the protection module will first act to close the load of the fault circuit, on this basis, on the one hand, the MCU can detect the fault through the detection module and control to reduce the total power of the two loads in the corresponding multiplexing module. On the other hand, the MCU can send a high-voltage control signal to make T1 open, T2 also open, the gate voltage of Q1 and Q2 rise, Q1 and Q2 are both open, GND1 and GND2 are connected, so that the load in the circuit where the ground fault occurs can form a loop through another grounding point, without affecting its normal work.

[0071] On the other hand, the embodiment of the present application also provides a ground fault protection device, which comprises the ground fault protection circuit in the above embodiment, and a connector and a storage battery.

[0072] The N positive poles of the storage battery are one-to-one plugged into the N power input ends of the connector, and the N negative poles of the storage battery are one-to-one plugged into the N grounding ends of the connector.

[0073] The beneficial effects of the ground fault protection device are the same as those of the ground fault protection circuit, which will not be repeated here.

[0074] On the other hand, the embodiment of the present application also provides a vehicle, which comprises the ground fault protection circuit in the above embodiment, and a connector and a storage battery.

[0075] The N positive poles of the storage battery are one-to-one plugged into the N power input ends of the connector, and the N negative poles of the storage battery are one-to-one plugged into the N grounding ends of the connector.

[0076] The beneficial effects of the vehicle are the same as those of the ground fault protection circuit, which will not be repeated here.

[0077] On the other hand, the embodiment of the present application also provides a ground fault protection method, which is applied to the ground fault protection circuit in the above embodiment. The ground fault protection circuit comprises a micro control unit, N loads, a detection module corresponding to each load and a protection module, and (N-1) multiplexing modules, N is a positive integer greater than 1. As shown in the figure, Figure 6 The ground fault protection method comprises the following steps S601-S603.

[0078] S601, when a ground fault occurs at the grounding end connected to the second end of the corresponding detection module, the protection module closes the load connected to the protection module.

[0079] S602, the detection module inputs a detection signal to the micro control unit, and the detection signal is used to indicate whether the ground end connected to the second end of the detection module has a ground fault.

[0080] S603, the micro control unit controls to reduce the total power of two loads and controls the multiplexing module to be turned on when the ground end connected to the second end of one detection module has a ground fault or the ground end connected to the second end of other detection module has a ground fault, so that the second end of one detection module is short-circuited with the second end of other detection module, and the two loads are the loads connected to one detection module and other detection module respectively.

[0081] The beneficial effects of the ground fault protection method are the same as those of the ground fault protection circuit, which will not be repeated here.

[0082] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A ground fault protection circuit, comprising: The ground fault protection circuit comprises a micro control unit, N loads, a detection module and a protection module corresponding to each load, and N-1 multiplexing modules, N being a positive integer greater than 1; Each detection module is connected with one power input end of the connector, is connected with two ground ends of the connector respectively, and is connected with the micro control unit; one detection module is further connected with the input end and the output end of one load respectively; Each protection module is connected with the corresponding detection module and the enable end of the load connected with the detection module; Each multiplexing module is connected with one detection module and is connected with other detection modules, and is connected with the micro control unit, the other detection modules being any detection module except the one detection module; The protection module is used for closing the load connected with the protection module when the ground fault occurs in the ground end connected with the corresponding detection module; The detection module is used for inputting a detection signal to the micro control unit, the detection signal being used for indicating whether the ground fault occurs in the ground end connected with the detection module; The micro control unit is used for controlling to reduce the total power of two loads and controlling the multiplexing module to be turned on when the ground fault occurs in the ground end connected with the one detection module or the ground fault occurs in the ground end connected with the other detection module, the two loads being the loads connected with the one detection module and the other detection module respectively.

2. The ground fault protection circuit of claim 1, wherein, The detection module comprises a first resistor, a second resistor and a third resistor; One end of the first resistor is connected with one power input end of the connector, the other end of the first resistor is connected with the micro control unit and one end of the second resistor, the other end of the second resistor is connected with one ground end of the connector and one end of the third resistor, and the other end of the third resistor is connected with the other ground end of the connector.

3. The ground fault protection circuit of claim 1 or 2, wherein, The protection module comprises a first protection submodule and a second protection submodule; The first protection submodule is connected with the corresponding detection module of the protection module and the second protection submodule; the second protection submodule is further connected with the enable end of the load connected with the detection module; The first protection submodule is used for outputting a first voltage signal and outputting a second voltage signal when the ground fault occurs in the ground end connected with the corresponding detection module; The second protection submodule is used for inputting a prohibition signal to the load according to the first voltage signal and the second voltage signal to close the load.

4. The ground fault protection circuit of claim 3, wherein, The first protection submodule comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first diode and a second diode; One end of the fourth resistor is connected to the detection module corresponding to the protection module, the other end of the fourth resistor is connected to the second protection submodule, and is connected to one end of the fifth resistor, the other end of the fifth resistor is connected to the anode of the first diode and the anode of the second diode, the cathode of the first diode is connected to the detection module corresponding to the protection module, and is connected to one end of the sixth resistor, the other end of the sixth resistor is connected to the detection module corresponding to the protection module, and is connected to the cathode of the second diode and one end of the seventh resistor, the other end of the seventh resistor is connected to the second protection submodule and one end of the eighth resistor, the other end of the eighth resistor is connected to the detection module corresponding to the protection module.

5. The ground fault protection circuit of claim 3, wherein, The second protection submodule comprises an operational amplifier; The non-inverting input end of the operational amplifier is connected to the first protection submodule, the inverting input end of the operational amplifier is connected to the first protection submodule, and the output end of the operational amplifier is connected to the enable end of the load connected to the detection module.

6. The ground fault protection circuit of claim 1 or 2, wherein, The multiplexing module comprises a first switch submodule and a second switch submodule; The first switch submodule is connected to one detection module, connected to other detection modules, connected to the second switch submodule, and connected to the micro control unit; The second switch submodule is also connected to one detection module and connected to other detection modules; The first switch submodule is configured to receive a control signal sent by the micro control unit, and input a conduction voltage signal to the second switch submodule according to the control signal; The second switch submodule is configured to conduct the second switch submodule according to the conduction voltage signal.

7. The ground fault protection circuit of claim 6, wherein, The first switch submodule comprises a ninth resistor, a tenth resistor, an eleventh resistor, a third diode, a fourth diode, a fifth diode, a sixth diode, a first triode and a second triode, the first triode is an NPN type triode, and the second triode is a PNP type triode; The anode of the third diode is connected to one detection module, the cathode of the third diode is connected to one end of the ninth resistor, one end of the tenth resistor, and the cathode of the fourth diode; The anode of the fourth diode is connected to other detection modules; The other end of the ninth resistor is connected to the collector of the first triode and the base of the second triode; The base of the first triode is connected to the micro control unit, the emitter of the first triode is connected to the anode of the fifth diode, the anode of the sixth diode, and one end of the eleventh resistor; The cathode of the fifth diode is connected to one detection module; The cathode of the sixth diode is connected to other detection modules; The other end of the eleventh resistor is connected to the second switch submodule and the collector of the second triode, and the emitter of the second triode is connected to the other end of the tenth resistor.

8. The ground fault protection circuit of claim 6, wherein, The second switch submodule comprises a first field effect transistor and a second field effect transistor, the first field effect transistor is an N-channel field effect transistor, and the second field effect transistor is an N-channel field effect transistor; The drain of the first field effect transistor is connected with other detection modules, the gate of the first field effect transistor is connected with the first switch submodule and the gate of the second field effect transistor, the source of the first field effect transistor is connected with the source of the second field effect transistor, and the drain of the second field effect transistor is connected with one detection module.

9. A ground fault protection device, characterized by, The ground fault protection device comprises the ground fault protection circuit according to any one of claims 1-8, and a connector and a battery; N positive poles of the battery are one-to-one plugged with N power input ends of the connector, and N negative poles of the battery are one-to-one plugged with N ground ends of the connector.

10. A vehicle characterized by comprising: The vehicle comprises the ground fault protection circuit according to any one of claims 1-8, and a connector and a battery; N positive poles of the battery are one-to-one plugged with N power input ends of the connector, and N negative poles of the battery are one-to-one plugged with N ground ends of the connector.

11. A method of ground fault protection, characterized by, The ground fault protection circuit comprises a micro control unit, N loads, a detection module and a protection module corresponding to each load, and N-1 multiplexing modules, N is a positive integer greater than 1; The ground fault protection method comprises: The protection module closes the load connected with the protection module when a ground fault occurs in the ground end connected with the corresponding detection module; The detection module inputs a detection signal to the micro control unit, and the detection signal is used to indicate whether a ground fault occurs in the ground end connected with the detection module; The micro control unit controls to reduce the total power of two loads and controls the multiplexing module to be turned on when a ground fault occurs in the ground end connected with the detection module or a ground fault occurs in the ground end connected with other detection modules, the two loads are the loads connected with the detection module and the other detection module respectively.

Images