Bus short circuit fault detection circuit and method

Abstract

The invention relates to a bus short circuit fault detection circuit and method. The detection circuit comprises a first signal line, a second signal line, a power supply module, n external detection modules and n fault response modules. Branches of the bus are connected in parallel through a first signal line and a second signal line, the external detection module is electrically connected with the first signal line and the second signal line, the fault response module is connected with the first signal line and the second signal line in series, and the external detection module is electrically connected with the fault response module. The external detection module and the fault response module are electrically connected with the power supply module. According to the invention, the external detection module controls each fault response module to cut off the power supply of each branch circuit of the bus according to the occurrence of the short-circuit fault, after the power supply is cut off, the power supply of the bus branch circuit without the short-circuit fault is recovered, and the external detection module corresponding to the bus branch circuit with the short-circuit fault sends a fault prompt. Therefore, a worker can accurately and quickly determine the position of the bus branch with the short-circuit fault.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fault detection, and in particular to a detection circuit and method for a bus short circuit fault. Background Art

[0002] As a serial communication bus, CAN (Controller Area Network) bus has been widely used in the transmission of data and control signals between various controllers of automotive electronics. Short circuit faults of CAN bus are generally caused by the wear of the insulation layer of the CAN bus harness, which causes the inner conductor to be exposed and touch other power lines, signal lines or ground lines. The occurrence of short circuit faults will cause the voltage of the CAN bus to be disturbed by external voltage, eventually causing CAN communication failure.

[0003] The prior art usually adopts a serial troubleshooting method. After a short circuit fault occurs, the relays need to be turned on from one side of the CAN bus from near to far. The more CAN nodes there are in the CAN bus, the longer the serial troubleshooting takes. Therefore, how to quickly troubleshoot the CAN bus short circuit fault has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0004] In order to solve the above technical problem or at least partially solve the above technical problem, the present disclosure provides a bus short circuit fault detection circuit and method.

[0005] The present disclosure provides a detection circuit for a bus short-circuit fault, comprising: a first signal line, a second signal line, a power supply module, n external detection modules and n fault response modules; the external detection modules and the fault response modules are arranged in a one-to-one correspondence with the branches of the bus; the branches of the bus are connected in parallel through the first signal line and the second signal line, the two detection ends of the n external detection modules are electrically connected to the first signal line and the second signal line respectively, the fault response module is connected in series with the first signal line and the second signal line, the n fault response modules are connected in parallel with each other, the external detection module is electrically connected to the fault response module, and the n external detection modules and the n fault response modules are all electrically connected to the power supply module; wherein n is an integer not less than 2; the external detection module is used to control the fault response module to cut off the connection between the first signal line and the second signal line and the branch of the bus according to the occurrence of a short-circuit fault in any branch of the bus, and to prompt the occurrence of a fault; the power supply module is used to supply power to the external detection module and the fault response module; the fault response module is used to control the first signal line and the second signal line to be connected to the branch of the bus according to the fact that no short-circuit fault occurs in the branch of the bus after the connection is cut off.

[0006] Optionally, the external detection module includes two detection units and a first prompt unit; the detection end of one detection unit is electrically connected to the first signal line, the detection end of the other detection unit is electrically connected to the second signal line, the output ends of the two detection units are electrically connected to the control end of the fault response module, and the output ends of the two detection units are also electrically connected to the control end of the first prompt unit.

[0007] Optionally, the detection unit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, a first pull-up resistor and a detection chip; the first signal line or the second signal line is electrically connected to the first end of the first voltage-dividing resistor, the second end of the first voltage-dividing resistor is electrically connected to the first end of the second voltage-dividing resistor at a first node, and the second end of the second voltage-dividing resistor is grounded; the first signal line or the second signal line is also electrically connected to the first end of the third voltage-dividing resistor, the second end of the third voltage-dividing resistor is electrically connected to the first end of the fourth voltage-dividing resistor at a second node, and the second end of the fourth voltage-dividing resistor is grounded; the first detection end of the detection chip is electrically connected to the first node, the second detection end of the detection chip is electrically connected to the second node, the power supply end of the detection chip is electrically connected to the power supply module, the first end of the detection chip is grounded, the first output end of the detection chip and the second output end of the detection chip are electrically connected to the power supply module through the first pull-up resistor, the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the fault response module, and the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the first prompt unit.

[0008] Optionally, the first prompt unit includes a first diode; the positive terminal of the first diode is electrically connected to the power supply module, and the negative terminal of the diode is electrically connected to the output terminals of the two detection units.

[0009] Optionally, the fault response module includes a switch unit and a power supply recovery unit; any branch of the bus is electrically connected to the first end of the switch unit through a first signal line, any branch of the bus is electrically connected to the second end of the switch unit through a second signal line, the third end of the switch unit is electrically connected to other branches of the bus through the first signal line, the fourth end of the switch unit is electrically connected to other branches of the bus through the second signal line, the control end of the switch unit is electrically connected to the output end of the external detection module, the first end of the power supply recovery unit is electrically connected to the corresponding first signal line, the second end of the power supply recovery unit is electrically connected to the corresponding second signal line, and the third end of the power supply recovery unit is electrically connected to the power supply module.

[0010] Optionally, the switching unit includes a relay, a second pull-up resistor, a PNP transistor, a second diode and a third diode; any branch of the bus is electrically connected to the first end of the relay through the first signal line, any branch of the bus is electrically connected to the second end of the relay through the second signal line, the third end of the relay is electrically connected to other branches of the bus through the first signal line, the fourth end of the relay is electrically connected to other branches of the bus through the second signal line, the fifth end of the relay is grounded, the fifth end of the relay is also electrically connected to the positive end of the second diode, the negative end of the second diode is electrically connected to the sixth end of the relay, the negative end of the second diode is also electrically connected to the collector of the PNP transistor, the emitter of the PNP transistor is electrically connected to the power supply module, the base of the PNP transistor is electrically connected to the power supply module through the second pull-up resistor, the base of the PNP transistor is also electrically connected to the positive end of the third diode, and the negative end of the third diode is electrically connected to the output end of the external detection module.

[0011] Optionally, the power supply recovery unit includes a fifth voltage-dividing resistor, a sixth voltage-dividing resistor, a seventh voltage-dividing resistor and an eighth voltage-dividing resistor; the first end of the fifth voltage-dividing resistor is electrically connected to the power supply module, the second end of the fifth voltage-dividing resistor is electrically connected to the first end of the sixth voltage-dividing resistor and the third node, the second end of the sixth voltage-dividing resistor is grounded, the first end of the seventh voltage-dividing resistor is electrically connected to the power supply module, the second end of the seventh voltage-dividing resistor is electrically connected to the first end of the eighth voltage-dividing resistor and the fourth node, the second end of the eighth voltage-dividing resistor is grounded, the third node is electrically connected to the first signal line, and the fourth node is electrically connected to the second signal line.

[0012] Optionally, the detection circuit also includes an internal detection module; a first detection end of the internal detection module is electrically connected to the first signal line, a second detection end of the internal detection module is electrically connected to the second signal line, and an output end of the internal detection module is electrically connected to a control end of each fault response module; wherein the internal detection module is used to control all fault response modules to cut off power supply to all branches of the bus according to the short-circuit fault conditions of the first signal line and the second signal line between each branch of the bus.

[0013] Optionally, the internal detection module also includes a bus power supply simulation unit; the input end of the bus power supply simulation unit is electrically connected to the power supply module, the first power supply end of the bus power supply simulation unit is electrically connected to the first signal line, and the second power supply end of the bus power supply simulation unit is electrically connected to the second signal line; wherein the bus power supply simulation unit is used to cut off the power supply of all branches of the bus according to the fault response module, and provide bus voltage for the first signal line and the second signal line.

[0014] The present disclosure also provides a method for detecting a bus short-circuit fault, wherein the detection circuit comprises a first signal line, a second signal line, a power supply module, n external detection modules and n fault response modules; the external detection modules and the fault response modules are arranged in a one-to-one correspondence with the branches of the bus; the branches of the bus are connected in parallel through the first signal line and the second signal line, the two detection ends of the n external detection modules are electrically connected to the first signal line and the second signal line respectively, the fault response module is connected in series with the first signal line and the second signal line, the n fault response modules are connected in parallel with each other, the external detection module is electrically connected to the fault response module, and the n external detection modules and the n fault response modules are all electrically connected to the power supply module; wherein n is an integer not less than 2; the method comprises: obtaining the short-circuit fault condition of any branch of the bus; based on the occurrence of a short-circuit fault in any branch of the bus, controlling all fault response modules to cut off the power supply of the branch of the bus where they are located, and controlling the external detection modules to issue a fault prompt; based on the fact that no short-circuit fault occurs in other branches of the bus, controlling the fault response modules to restore the power supply of other branches of the bus, and controlling the external detection modules to stop issuing a fault prompt.

[0015] The present disclosure provides a detection circuit and method for a bus short-circuit fault, wherein the detection circuit includes a first signal line, a second signal line, a power supply module, n external detection modules, and n fault response modules, wherein n is an integer not less than 2. Since the branches of the bus are arranged in a one-to-one correspondence with the external detection modules and the fault response modules, the number of external detection modules and the number of fault detection modules are the same as the number of bus branches, and the external detection module can detect the short-circuit fault of the corresponding bus branch. When a short-circuit fault occurs in a branch of the bus, the voltage of the branch will be abnormal, thereby causing the voltage on the first signal line and the second signal line to be abnormal. Therefore, all external detection modules will detect the occurrence of a short-circuit fault, and control the corresponding fault response module to cut off the connection between the first signal line and the second signal line and the bus branch, so as to disconnect the power supply from each branch of the bus to the first signal line and the second signal line. After the power supply is cut off, the power supply module supplies power to each branch of the bus through each fault response module, and the bus branch with a short circuit fault still has a voltage abnormality, while other bus branches without a short circuit fault do not have a voltage abnormality. At this time, the fault response module corresponding to the bus branch without a voltage abnormality will restore the connection between the bus branch and the first signal line and the second signal line to restore the power supply, and the bus branch with a voltage abnormality will continue to remain disconnected. In addition, since the external detection module will issue a corresponding fault prompt information after detecting a short circuit fault, when the power supply is just cut off, all external detection modules will issue a fault prompt, but in the stage of power supply recovery, only the external detection module corresponding to the bus branch with a short circuit fault will continue to issue a fault prompt, and other external detection modules will stop issuing fault prompts due to the recovery of power supply of the bus branch. Therefore, the present disclosure realizes that only the bus branch with a short circuit fault will issue a corresponding fault prompt, so that the staff can quickly and accurately determine the location of the bus branch with a short circuit fault, thereby improving the detection efficiency of the bus short circuit fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a bus short circuit fault detection circuit provided in an embodiment of the present disclosure.

[0018] Figure 2 A schematic structural diagram of a preferred bus short-circuit fault detection circuit provided in an embodiment of the present disclosure.

[0019] Figure 3 A schematic flow chart of a method for detecting a bus short circuit fault provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0022] Figure 1 A schematic diagram of a bus short circuit fault detection circuit provided by an embodiment of the present disclosure is shown in FIG. Figure 1 As shown, the detection circuit includes: a first signal line 101, a second signal line 102, a power supply module 103, n external detection modules and n fault response modules; the external detection modules and the fault response modules are arranged in one-to-one correspondence with the branches of the bus; each branch of the bus is connected in parallel through the first signal line 101 and the second signal line 102, two detection ends of the n external detection modules are electrically connected to the first signal line 101 and the second signal line 102 respectively, the fault response module is connected in series with the first signal line 101 and the second signal line 102, the n fault response modules are connected in parallel with each other, and the external detection module is electrically connected to the fault response module The n external detection modules and the n fault response modules are all electrically connected to the power supply module 103; wherein n is an integer not less than 2; the external detection module is used to control the fault response module to cut off the connection between the first signal line 101 and the second signal line 102 and the branch of the bus according to a short circuit fault in any branch of the bus, and to prompt the occurrence of a fault; the power supply module 103 is used to supply power to the external detection module and the fault response module; the fault response module is used to control the first signal line 101 and the second signal line 102 to be conductive with the branch of the bus according to the fact that no short circuit fault occurs in the branch of the bus after the connection is cut off.

[0023] Exemplarily, taking n as 3 as an example, the external detection module includes a first external detection module 210, a second external detection module 220 and a third external detection module 230, the fault response module includes a first fault response module 310, a second fault response module 320 and a third fault response module 330, and the bus includes a first branch 410, a second branch 420 and a third branch 430.

[0024] The first external detection module 210 and the first fault response module 310 are arranged corresponding to the first branch 410, the second external detection module 220 and the second fault response module 320 are arranged corresponding to the second branch 420, and the third external detection module 230 and the third fault response module 330 are arranged corresponding to the third branch 430. The first branch 410, the second branch 420 and the third branch 430 are connected in parallel through the first signal line 101 and the second signal line 102, and the first fault response module 310, the second fault response module 320 and the third fault response module 330 are connected in series to the first signal line 101 and the second signal line 102. The first detection end of the first external detection module 210 is electrically connected to the first signal line 101, and the second detection end of the first external detection module 210 is electrically connected to the second signal line 102. The first detection end of the second external detection module 220 is electrically connected to the first signal line 101, and the second detection end of the second external detection module 220 is electrically connected to the second signal line 102. The first detection end of the third external detection module 230 is electrically connected to the first signal line 101 , and the second detection end of the third external detection module 230 is electrically connected to the second signal line 102 .

[0025] The example of a short circuit failure in the first branch 410 is used to explain that when a short circuit failure occurs in the first branch 410, the first branch 410 will have an overvoltage or undervoltage problem. At this time, the voltages on the first signal line 101 and the second signal line 102 will change, causing the first external detection module 210, the second external detection module 220 and the third external detection module 230 connected to the first signal line 101 and the second signal line 102 to detect the short circuit failure, issue a fault prompt, and control the corresponding fault response module to cut off the power supply of each branch of the bus to the first signal line 101 and the second signal line 102. After the power supply is cut off, the power supply module 103 supplies power to the first branch 410, the second branch 420 and the third branch 430 through various fault response modules. Since each fault response module has disconnected the connection between the bus branches, the short circuit fault in the first branch 410 cannot affect other bus branches. Therefore, when the power supply module 103 supplies power to the bus branches, only the first external detection module 210 can detect the short circuit fault, and the other external detection modules detect normally. Therefore, at this time, only the first external detection module 210 issues a fault prompt, and only the first fault response module 310 keeps cutting off the connection between the first branch 410 and the first signal line 101 and the second signal line 102, and the other fault response modules restore the connection.

[0026] Therefore, the present disclosure detects the short-circuit fault of the corresponding bus branch through the external detection module. When a short-circuit fault occurs in a branch of the bus, the voltage of the branch will be abnormal, thereby causing the voltage on the first signal line 101 and the second signal line 102 to be abnormal. Therefore, all external detection modules will detect the occurrence of the short-circuit fault and control the corresponding fault response module to cut off the connection between the first signal line 101 and the second signal line 102 and the bus branch, so as to disconnect the power supply from each bus branch to the first signal line 101 and the second signal line 102. After the power supply is cut off, the power supply module 103 supplies power to each bus branch through each fault response module, and the bus branch with the short-circuit fault still has a voltage abnormality, while other bus branches without the short-circuit fault do not have a voltage abnormality. At this time, the fault response module corresponding to the bus branch without the voltage abnormality will restore the connection between the bus branch and the first signal line 101 and the second signal line 102 to restore the power supply, and the bus branch with the voltage abnormality will continue to remain disconnected. Furthermore, since the external detection module will issue a corresponding fault prompt information after detecting a short-circuit fault, when the power supply is just cut off, all external detection modules will issue a fault prompt, but when the power supply is restored, only the external detection module corresponding to the bus branch with the short-circuit fault will continue to issue a fault prompt, and other external detection modules will stop issuing fault prompts due to the restoration of power supply of the bus branch. Therefore, the present disclosure realizes that only the bus branch with a short-circuit fault will issue a corresponding fault prompt, so that the staff can quickly and accurately determine the location of the bus branch with the short-circuit fault, thereby improving the detection efficiency of the bus short-circuit fault.

[0027] It should be noted that n being 3 is only an example, and n may also be other integers not less than 2. The specific number is determined according to the number of branches of the bus and is not specifically limited here.

[0028] In some embodiments, the external detection module includes two detection units and a first prompt unit; the detection end of one detection unit is electrically connected to the first signal line, the detection end of the other detection unit is electrically connected to the second signal line, the output ends of the two detection units are electrically connected to the control end of the fault response module, and the output ends of the two detection units are also electrically connected to the control end of the first prompt unit.

[0029] Specifically, each branch of the bus includes a high voltage signal line and a low voltage signal line, the high voltage signal line is electrically connected to the first signal line, and the low voltage signal line is electrically connected to the second signal line. When a short circuit fault occurs in the high voltage signal line, the voltage of the first signal line changes. When a fault occurs in the low voltage signal line, the voltage of the second signal line changes. The two detection units include a first detection unit and a second detection unit, the detection end of the first detection unit is electrically connected to the first signal line, and the detection end of the second detection unit is electrically connected to the second signal line. The first detection unit detects the voltage condition of the first signal line. When it is detected that the voltage of the first signal line is overvoltage or undervoltage, the first detection unit outputs a control signal through the output end, controls the fault response module to cut off the connection between the bus branch and the first signal line and the second signal line, and controls the first prompt unit to issue a fault prompt. The second detection unit detects the voltage condition of the second signal line. When it is detected that the voltage of the second signal line is overvoltage or undervoltage, the second detection unit outputs a control signal through the output end, controls the fault response module to cut off the connection between the bus branch and the first signal line and the second signal line, and controls the first prompt unit to issue a fault prompt. Therefore, when a short circuit fault occurs in any one of the high voltage signal line or the low voltage signal line of the bus, or both of them, the first detection unit will output a control signal according to the voltage condition of the first signal line, and the second detection unit will output a control signal according to the voltage condition of the second signal line, so that as long as a short circuit fault occurs in the bus branch, no matter whether the high voltage signal line or the low voltage signal line fails, the fault response module will be controlled to cut off the connection between the bus branch and the first signal line and the second signal line. Therefore, the present disclosure realizes the separate detection of short circuit faults of the high voltage signal line and the low voltage signal line by respectively providing detection units for the first signal line and the second signal line for detection, thereby improving the accuracy of detection.

[0030] In some embodiments, the detection unit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, a first pull-up resistor and a detection chip; the first signal line or the second signal line is electrically connected to the first end of the first voltage-dividing resistor, the second end of the first voltage-dividing resistor is electrically connected to the first end of the second voltage-dividing resistor at a first node, and the second end of the second voltage-dividing resistor is grounded; the first signal line or the second signal line is also electrically connected to the first end of the third voltage-dividing resistor, the second end of the third voltage-dividing resistor is electrically connected to the first end of the fourth voltage-dividing resistor at a second node, and the second end of the fourth voltage-dividing resistor is grounded; the first detection end of the detection chip is electrically connected to the first node, the second detection end of the detection chip is electrically connected to the second node, the power supply end of the detection chip is electrically connected to the power supply module, the first end of the detection chip is grounded, the first output end of the detection chip and the second output end of the detection chip are electrically connected to the power supply module through the first pull-up resistor, the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the fault response module, and the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the first prompt unit.

[0031] Exemplarily, a first voltage-dividing resistor and a second voltage-dividing resistor divide the 2.5V voltage provided by the signal line, the first voltage-dividing resistor and the second voltage-dividing resistor are electrically connected to a first node, and the first detection end of the detection chip performs undervoltage detection on the voltage at the first node. A third voltage-dividing resistor and a fourth voltage-dividing resistor are electrically connected to a second node, and the second detection end of the detection chip performs overvoltage detection on the voltage at the second node. When there is no short circuit fault in the bus branch, the power supply module pulls up the first output end and the second output end of the detection chip to a high-level signal with a voltage of 5V through a first pull-up resistor, so that the control end of the fault response module receives the high-level signal.

[0032] Taking the first signal line connected to the high voltage signal line of the bus as an example, the resistance of the first voltage-dividing resistor connected to the first signal line is 500KΩ, the resistance of the second voltage-dividing resistor is 100KΩ, the resistance of the third voltage-dividing resistor is 500KΩ, and the resistance of the fourth voltage-dividing resistor is 60KΩ. When the first signal line is under-voltage, the voltage of the first signal line is lower than 2.375V. After the voltage is divided by the first voltage-dividing resistor and the second voltage-dividing resistor, the first detection end of the detection chip detects that the voltage at the first node will be lower than 0.3945V, and the first output end of the detection chip outputs a low-level signal, thereby causing the control end of the fault response module to receive a low-level signal. When the first signal line is over-voltage, the voltage of the first signal line is higher than 3.675V, and the second detection end of the detection chip detects that the voltage at the second node will be higher than 0.4V, and the first output end of the detection chip outputs a low-level signal, thereby causing the control end of the fault response module to receive a low-level signal.

[0033] Taking the second signal line connected to the low voltage signal line of the bus as an example, the resistance of the first voltage-dividing resistor connected to the second signal line is 500KΩ, the resistance of the second voltage-dividing resistor is 193KΩ, the resistance of the third voltage-dividing resistor is 500KΩ, and the resistance of the fourth voltage-dividing resistor is 89KΩ. When the second signal line is under-voltage, the voltage of the second signal line is lower than 1.425V. After the voltage is divided by the first voltage-dividing resistor and the second voltage-dividing resistor, the first detection end of the detection chip detects that the voltage at the first node will be lower than 0.3945V, and the first output end of the detection chip outputs a low-level signal, thereby causing the control end of the fault response module to receive a low-level signal. When the second signal line is over-voltage, the voltage of the second signal line is higher than 2.625V, and the second detection end of the detection chip detects that the voltage at the second node will be higher than 0.4V, and the first output end of the detection chip outputs a low-level signal, thereby causing the control end of the fault response module to receive a low-level signal.

[0034] Therefore, the present disclosure divides the voltage provided by the signal line through the first voltage-dividing resistor, the second voltage-dividing resistor, the third voltage-dividing resistor and the fourth voltage-dividing resistor, and detects the overvoltage and undervoltage conditions of the signal line through the detection unit. As long as any overvoltage or undervoltage condition occurs, the detection unit will output a low-level signal to the control end of the fault response module, so that the fault response module cuts off the connection between the bus branch and the signal line. When the detection unit detects that the voltage condition of the signal line has returned to normal, it will still re-output a high-level signal to enable the fault response module to restore the connection between the bus branch and the signal line, so that only the fault response module corresponding to the bus branch where the fault occurs can be kept in the state of disconnecting the bus branch from the signal line, so that the staff can quickly and accurately determine the location of the fault.

[0035] It should be noted that the voltage provided by the signal line is 2.5V, and the resistance values ​​of the first voltage-dividing resistor, the second voltage-dividing resistor, the third voltage-dividing resistor and the fourth voltage-dividing resistor are all examples. The specific signal line voltage and the resistance values ​​of the voltage-dividing resistors should be set according to the actual situation of the detection end of the detection unit, and no specific limitation is made here.

[0036] In some embodiments, the first prompt unit includes a first diode; the positive terminal of the first diode is electrically connected to the power supply module, and the negative terminal of the diode is electrically connected to the output terminals of the two detection units.

[0037] Specifically, the two detection units include a first detection unit and a second detection unit, the detection end of the first detection unit is electrically connected to the first signal line, and the detection end of the second detection unit is electrically connected to the second signal line. When there is no short circuit fault in the bus branch, the cathode end of the first diode receives a high level signal from the output end of the first detection unit and a high level signal output from the output end of the second detection unit, so the first diode is not turned on and does not emit light. When a short circuit fault occurs in the bus branch, the first detection unit will output a low level signal according to the short circuit fault of the high voltage signal line of the bus, and the second detection unit will output a low level signal according to the short circuit fault of the low voltage signal line of the bus, so that no matter whether the high voltage signal line of the bus branch or the low voltage signal line of the bus branch has a short circuit fault, the cathode end of the first diode will receive a low level signal and turn on to emit light, so that the first prompt unit issues a fault prompt.

[0038] In some embodiments, the fault response module includes a switch unit and a power supply recovery unit; any branch of the bus is electrically connected to the first end of the switch unit through a first signal line, any branch of the bus is electrically connected to the second end of the switch unit through a second signal line, the third end of the switch unit is electrically connected to other branches of the bus through the first signal line, the fourth end of the switch unit is electrically connected to other branches of the bus through the second signal line, the control end of the switch unit is electrically connected to the output end of the external detection module, the first end of the power supply recovery unit is electrically connected to the corresponding first signal line, the second end of the power supply recovery unit is electrically connected to the corresponding second signal line, and the third end of the power supply recovery unit is electrically connected to the power supply module.

[0039] Specifically, when the external detection module detects that a short circuit fault occurs in a bus branch, the external detection module outputs a control signal to the control end of the switch unit, so that the switch unit cuts off the connection between the bus branch and the first signal line and the second signal line, thereby disconnecting the connection between the bus branch and other bus branches. After all fault response modules have cut off the connection between the bus branch and other bus branches through the switch unit, the power supply module provides bus voltage to each branch of the bus through the power supply recovery unit. Since each fault response module has disconnected the connection between each bus branch, the power supply module forms an independent loop with each bus branch through the power supply recovery unit in the fault response module. Therefore, the bus branch with a short circuit fault cannot affect other bus branches. Therefore, when the power supply module supplies power to each bus branch, only the external detection module corresponding to the bus branch with a short circuit fault can detect the short circuit fault, while other external detection modules detect no abnormality. Therefore, at this time, only the external detection module corresponding to the bus branch with a short circuit fault issues a fault prompt, and only the switch unit corresponding to the bus branch with a short circuit fault is disconnected, and the switch units in other fault response modules are turned on again. Therefore, the present disclosure realizes that only the bus branch where a short circuit fault occurs will issue a corresponding fault prompt, so that the staff can quickly and accurately determine the location of the bus branch where the short circuit fault occurs, thereby improving the detection efficiency of the bus short circuit fault.

[0040] In some embodiments, the switching unit includes a relay, a second pull-up resistor, a PNP transistor, a second diode and a third diode; any branch of the bus is electrically connected to the first end of the relay through the first signal line, any branch of the bus is electrically connected to the second end of the relay through the second signal line, the third end of the relay is electrically connected to other branches of the bus through the first signal line, the fourth end of the relay is electrically connected to other branches of the bus through the second signal line, the fifth end of the relay is grounded, the fifth end of the relay is also electrically connected to the positive end of the second diode, the negative end of the second diode is electrically connected to the sixth end of the relay, the negative end of the second diode is also electrically connected to the collector of the PNP transistor, the emitter of the PNP transistor is electrically connected to the power supply module, the base of the PNP transistor is electrically connected to the power supply module through the second pull-up resistor, the base of the PNP transistor is also electrically connected to the positive end of the third diode, and the negative end of the third diode is electrically connected to the output end of the external detection module.

[0041] Specifically, when there is no short circuit fault in the bus branch, the output end of the external detection circuit outputs a high level signal, the cathode end of the third diode and the anode end of the third diode are both high level, so the third diode is not conducting, the base of the PNP transistor is electrically connected to the power supply module through the second pull-up resistor, at this time, the PNP transistor is turned off due to the base receiving the high level signal, and since the PNP transistor is not conducting, there is no current passing between the fifth end of the relay and the sixth end of the relay, and the relay is in the conducting state, so that the bus branch is connected to the first signal line and the second signal line. When the external detection module detects that a short circuit fault occurs in the bus branch, the output end of the external detection module outputs a low level signal, the anode end of the third diode is high level, so the third diode is conducting, the PNP transistor is turned on due to the base receiving the low level signal, and there is current passing between the fifth end of the relay and the sixth end of the relay, and the relay is in the off state, thereby realizing that after a short circuit fault occurs, the connection between the bus branch and the first signal line and the second signal line is cut off by each relay.

[0042] In some embodiments, the power supply recovery unit includes a fifth voltage-dividing resistor, a sixth voltage-dividing resistor, a seventh voltage-dividing resistor and an eighth voltage-dividing resistor; the first end of the fifth voltage-dividing resistor is electrically connected to the power supply module, the second end of the fifth voltage-dividing resistor is electrically connected to the first end of the sixth voltage-dividing resistor and the third node, the second end of the sixth voltage-dividing resistor is grounded, the first end of the seventh voltage-dividing resistor is electrically connected to the power supply module, the second end of the seventh voltage-dividing resistor is electrically connected to the first end of the eighth voltage-dividing resistor and the fourth node, the second end of the eighth voltage-dividing resistor is grounded, the third node is electrically connected to the first signal line, and the fourth node is electrically connected to the second signal line.

[0043] Exemplarily, the power supply module provides a 5V power supply voltage, and the fifth voltage-dividing resistor, the sixth voltage-dividing resistor, the seventh voltage-dividing resistor and the eighth voltage-dividing resistor are resistors with equal resistance values, so the voltages at the third node and the fourth node are both 2.5V. After each switch unit cuts off the connection between each branch of the bus and the first signal line and the second signal line, the power supply module provides a voltage to the high voltage signal line of the bus connected to the first signal line through the fifth voltage-dividing resistor and the sixth voltage-dividing resistor, and provides a voltage to the low level signal line of the bus connected to the second signal line through the seventh voltage-dividing resistor and the eighth voltage-dividing resistor. If there is a short circuit fault in the bus branch, the external detection module will still detect the short circuit fault, thereby controlling the switch unit to remain in the disconnected state. If there is no short circuit fault in the bus branch, the external detection module will not detect the occurrence of the short circuit fault, thereby controlling the switch unit to switch to the on state, thereby restoring power to all bus branches except the bus branch where the short circuit fault occurs. As a result, only the external detection module corresponding to the bus branch where the short-circuit fault occurs will issue a fault prompt, so that the staff can quickly and accurately determine the location of the bus branch where the short-circuit fault occurs, thereby improving the detection efficiency of the bus short-circuit fault.

[0044] It should be noted that the voltage of 5V provided by the power supply module is only an example. The specific voltage provided by the power supply module should be set according to actual conditions and is not specifically limited here.

[0045] In some embodiments, the detection circuit also includes an internal detection module; a first detection end of the internal detection module is electrically connected to the first signal line, a second detection end of the internal detection module is electrically connected to the second signal line, and an output end of the internal detection module is electrically connected to a control end of each fault response module; wherein the internal detection module is used to control all fault response modules to cut off power supply to all branches of the bus according to the short-circuit fault conditions of the first signal line and the second signal line between each branch of the bus.

[0046] Specifically, after a short circuit fault occurs in the first signal line or the second signal line inside the detection circuit, the output end of the internal detection module outputs a control signal to the control end of all fault response modules, so that all fault response modules cut off the connection between all bus branches and the first signal line and the second signal line, and the internal detection module will also issue a corresponding short circuit fault prompt according to the short circuit fault situation, thereby achieving protection for each branch of the bus while enabling staff to quickly determine the location of the fault.

[0047] In some embodiments, the internal detection module also includes a bus power supply simulation unit; the input end of the bus power supply simulation unit is electrically connected to the power supply module, the first power supply end of the bus power supply simulation unit is electrically connected to the first signal line, and the second power supply end of the bus power supply simulation unit is electrically connected to the second signal line; wherein the bus power supply simulation unit is used to cut off the power supply of all branches of the bus according to the fault response module, and provide bus voltage for the first signal line and the second signal line.

[0048] Specifically, when a short circuit fault occurs in each branch of the bus, all fault response modules disconnect each bus branch from the first signal line and the second signal line, and the first signal line and the second signal line inside the detection circuit will be in a completely powered-off state. In the case of a short circuit fault inside the detection circuit, the first signal line and the second signal line inside the detection circuit will also be in a completely powered-off state. Therefore, after the first signal line and the second signal line inside the detection circuit are powered off, if the power supply to the first signal line and the second signal line inside the detection circuit is not restored to a normal voltage, the staff will mistakenly believe that there is also a short circuit fault inside the detection circuit. Therefore, the present disclosure also provides a bus power supply simulation unit in the internal detection module, and when the power is completely cut off inside the detection circuit, the bus voltage is started to be provided to the first signal line and the second signal line, so that the first signal line and the second signal line inside the detection circuit are restored to a normal voltage, and all external detection modules and internal detection modules can work normally. At this time, only the location where the short circuit fault occurs issues a fault prompt, that is, all external detection modules issue a fault prompt, so that the staff can quickly determine that the fault problem at this time is that all bus branches have a short circuit fault.

[0049] Figure 2 A schematic diagram of a preferred bus short circuit fault detection circuit provided by an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the detection circuit includes: a first signal line 101, a second signal line 102, a power supply module 103, an internal detection module 104, a bus power supply simulation unit 105, a first external detection module, a second external detection module, a third external detection module, a first fault response module, a second fault response module and a third fault response module. Each bus branch 400 is connected in parallel through the first signal line 101 and the second signal line 102.

[0050] Each external detection module includes a first voltage-dividing resistor R1 , a second voltage-dividing resistor R2 , a third voltage-dividing resistor R3 , a fourth voltage-dividing resistor R4 , a first pull-up resistor R9 , a detection chip U1 , and a first diode D1 .

[0051] The first signal line 101 or the second signal line 102 is electrically connected to the first end of the first voltage-dividing resistor R1, the second end of the first voltage-dividing resistor R1 and the first end of the second voltage-dividing resistor R2 are electrically connected to the first node A1, and the second end of the second voltage-dividing resistor R2 is grounded; the first signal line 101 or the second signal line 102 is also electrically connected to the first end of the third voltage-dividing resistor R3, the second end of the third voltage-dividing resistor R3 and the first end of the fourth voltage-dividing resistor R4 are electrically connected to the second node A2, and the second end of the fourth voltage-dividing resistor R4 is grounded; the first detection end of the detection chip U1 is electrically connected to the first node A1, and the second detection end of the detection chip U1 is electrically connected to the first node A1. The end is electrically connected to the second node A2, the power supply end of the detection chip U1 is electrically connected to the power supply module 103, the first end of the detection chip U1 is grounded, the first output end of the detection chip U1 and the second output end of the detection chip U1 are electrically connected to the power supply module 103 through the first pull-up resistor R9, the first output end of the detection chip U1 and the second output end of the detection chip U1 are also electrically connected to the control end of the corresponding fault response module, the first output end of the detection chip U1 and the second output end of the detection chip U1 are also electrically connected to the cathode end of the first diode D1, and the anode end of the first diode D1 is electrically connected to the power supply module 103.

[0052] Specifically, the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 divide the 2.5V voltage provided by the signal line, the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 are electrically connected to the first node A1, and the first detection end of the detection chip U1 performs undervoltage detection on the voltage at the first node A1. The third voltage-dividing resistor R3 and the fourth voltage-dividing resistor R4 are electrically connected to the second node A2, and the second detection end of the detection chip U1 performs overvoltage detection on the voltage at the second node A2. When there is no short circuit fault in the bus branch, the power supply module 103 pulls up the first output end of the detection chip U1 and the second output end of the detection chip U1 to a high-level signal with a voltage of 5V through the first pull-up resistor R9, so that the negative terminal of the first diode D1 receives the high-level signal, and the first diode D1 does not emit light.

[0053] Taking the first signal line 101 connected to the high voltage signal line of the bus as an example, the resistance of the first voltage-dividing resistor R1 connected to the first signal line 101 is 500KΩ, the resistance of the second voltage-dividing resistor R2 is 100KΩ, the resistance of the third voltage-dividing resistor R3 is 500KΩ, and the resistance of the fourth voltage-dividing resistor R4 is 60KΩ. When the first signal line 101 is undervoltage, the voltage of the first signal line 101 is lower than 2.375V. After the voltage is divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the first detection end of the detection chip U1 detects that the voltage at the first node A1 will be lower than 0.3945V, and the first output end of the detection chip U1 outputs a low-level signal, thereby causing the cathode end of the first diode D1 to receive the low-level signal, and the first diode D1 emits light. When overvoltage occurs on the first signal line 101, the voltage of the first signal line 101 is higher than 3.675V, and the second detection end of the detection chip U1 detects that the voltage at the second node A2 is higher than 0.4V. Then, the first output end of the detection chip U1 outputs a low-level signal, thereby causing the cathode end of the first diode D1 to receive the low-level signal, and the first diode D1 emits light.

[0054] Taking the second signal line 102 connected to the low voltage signal line of the bus as an example, the resistance of the first voltage-dividing resistor R1 connected to the second signal line 102 is 500KΩ, the resistance of the second voltage-dividing resistor R2 is 193KΩ, the resistance of the third voltage-dividing resistor R3 is 500KΩ, and the resistance of the fourth voltage-dividing resistor R4 is 89KΩ. When the second signal line 102 is undervoltage, the voltage of the second signal line 102 is lower than 1.425V. After the voltage is divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the first detection end of the detection chip U1 detects that the voltage at the first node A1 will be lower than 0.3945V, and the first output end of the detection chip U1 outputs a low-level signal, thereby causing the cathode end of the first diode D1 to receive the low-level signal, and the first diode D1 emits light. When overvoltage occurs on the second signal line 102, the voltage of the second signal line 102 is higher than 2.625V, and the second detection end of the detection chip U1 detects that the voltage at the second node A2 will be higher than 0.4V. Then, the first output end of the detection chip U1 outputs a low-level signal, thereby causing the cathode end of the first diode D1 to receive the low-level signal, and the first diode D1 emits light.

[0055] It should be noted that the voltage provided by the signal line is 2.5V, and the resistance values ​​of the first voltage-dividing resistor R1, the second voltage-dividing resistor R2, the third voltage-dividing resistor R3 and the fourth voltage-dividing resistor R4 are all examples. The specific signal line voltage and the resistance values ​​of the voltage-dividing resistors should be set according to the actual situation of the detection end of the detection chip U1, and no specific limitation is made here.

[0056] Each fault response module includes: a fifth voltage-dividing resistor R5, a sixth voltage-dividing resistor R6, a seventh voltage-dividing resistor R7, an eighth voltage-dividing resistor R8, a relay U2, a second pull-up resistor R10, a PNP transistor Q1, a second diode D2 and a third diode D3, wherein the third diode D3 is a two-in-one diode.

[0057] The first end of the fifth voltage-dividing resistor R5 is electrically connected to the power supply module 103, the second end of the fifth voltage-dividing resistor R5 and the first end of the sixth voltage-dividing resistor R6 are electrically connected to the third node A3, the second end of the sixth voltage-dividing resistor R6 is grounded, the first end of the seventh voltage-dividing resistor R7 is electrically connected to the power supply module 103, the second end of the seventh voltage-dividing resistor R7 and the first end of the eighth voltage-dividing resistor R8 are electrically connected to the fourth node A4, the second end of the eighth voltage-dividing resistor R8 is grounded, the third node A3 is electrically connected to the first signal line 101, and the fourth node A4 is electrically connected to the second signal line 102. Any branch of the bus is electrically connected to the first end of the relay U2 through the first signal line 101, any branch of the bus is electrically connected to the second end of the relay U2 through the second signal line 102, the third end of the relay U2 is electrically connected to other branches of the bus through the first signal line 101, the fourth end of the relay U2 is electrically connected to other branches of the bus through the second signal line 102, the fifth end of the relay U2 is grounded, the fifth end of the relay U2 is also electrically connected to the positive end of the second diode D2, the negative end of the second diode D2 is electrically connected to the sixth end of the relay U2 The cathode end of the second diode D2 is also electrically connected to the collector of the PNP type transistor Q1, the emitter of the PNP type transistor Q1 is electrically connected to the power supply module 103, the base of the PNP type transistor Q1 is electrically connected to the power supply module 103 through the second pull-up resistor R10, the base of the PNP type transistor Q1 is also electrically connected to the anode end of the third diode D3, the first cathode end of the third diode D3 is electrically connected to the output end of the corresponding external detection module, and the second cathode end of the third diode D3 is electrically connected to the internal detection module 104.

[0058] Exemplarily, the power supply module 103 provides a power supply voltage of 5V, and the fifth voltage-dividing resistor R5, the sixth voltage-dividing resistor R6, the seventh voltage-dividing resistor R7 and the eighth voltage-dividing resistor R8 are resistors with equal resistance values, so the voltages at the third node A3 and the fourth node A4 are both 2.5V. After each relay U2 cuts off the connection between each branch of the bus and the first signal line 101 and the second signal line 102, the power supply module 103 provides a voltage to the high-voltage signal line of the bus connected to the first signal line 101 through the fifth voltage-dividing resistor R5 and the sixth voltage-dividing resistor R6, and provides a voltage to the low-level signal line of the bus connected to the second signal line 102 through the seventh voltage-dividing resistor R7 and the eighth voltage-dividing resistor R8. When there is no short circuit fault in the bus branch 400, the output end of the detection chip U1 outputs a high-level signal, the cathode end of the third diode D3 and the anode end of the third diode D3 are both high levels, so the third diode D3 is not conducting, and the base of the PNP transistor Q1 is electrically connected to the power supply module 103 through the second pull-up resistor R10. At this time, the PNP transistor Q1 is turned off because the base receives a high-level signal. Since the PNP transistor Q1 is not conducting, no current passes between the fifth end of the relay U2 and the sixth end of the relay U2, and the relay U2 is in the on state, so that the bus branch 400 is connected to the first signal line 101 and the second signal line 102. When the detection chip U1 detects that the bus branch 400 has a short circuit fault, the output end of the detection chip U1 outputs a low-level signal, and the positive terminal of the third diode D3 is high level, so the third diode D3 is turned on, and the PNP transistor Q1 is turned on due to the base receiving the low-level signal. At this time, there is a current passing between the fifth end of the relay U2 and the sixth end of the relay U2, and the relay U2 is in the off state. When the internal detection module 104 detects that there is a short circuit fault inside the detection circuit, the internal detection module 104 outputs a low-level signal to the second negative terminal of the third diode D3 in each fault response module, so that all relays U2 are disconnected, and the internal detection module issues a fault prompt. Therefore, the present disclosure realizes that only the bus branch 400 with a short circuit fault will issue a corresponding fault prompt, so that the staff can quickly and accurately determine the location of the bus branch with a short circuit fault, thereby improving the detection efficiency of the bus short circuit fault.

[0059] It should be noted that the voltage of 5V provided by the power supply module 103 is only an example, and the specific voltage provided by the power supply module 103 should be set according to actual conditions and is not specifically limited here.

[0060] The first detection end of the internal detection module 104 is electrically connected to the first signal line 101, the second detection end of the internal detection module 104 is electrically connected to the second signal line 102, and the output end of the internal detection module 104 is electrically connected to the control end of each fault response module. The input end of the bus power supply simulation unit 105 is electrically connected to the power supply module 103, the first power supply end of the bus power supply simulation unit 105 is electrically connected to the first signal line 101, and the second power supply end of the bus power supply simulation unit 105 is electrically connected to the second signal line 102.

[0061] Specifically, when a short circuit occurs in each branch of the bus, all relays U2 disconnect each bus branch 400 from the first signal line 101 and the second signal line 102, and the first signal line 101 and the second signal line 102 inside the detection circuit will be in a completely powered-off state. In the case of a short circuit inside the detection circuit, the first signal line 101 and the second signal line 102 inside the detection circuit will also be in a completely powered-off state. Therefore, after the first signal line 101 and the second signal line 102 inside the detection circuit are powered off, if the power supply to the first signal line 101 and the second signal line 102 inside the detection circuit is not restored to normal voltage, the staff will mistakenly believe that there is also a short circuit inside the detection circuit. Therefore, the present disclosure further provides a bus power supply simulation unit 105 in the internal detection module 104. When the power is completely cut off inside the detection circuit, the bus voltage is provided to the first signal line 101 and the second signal line 102, so that the first signal line 101 and the second signal line 102 inside the detection circuit are restored to normal voltage, and all detection chips U1 and the internal detection module 104 can work normally. At this time, only the location where the short circuit fault occurs sends a fault prompt, that is, all the detection chips U1 send a fault prompt, so that the staff can quickly determine that the fault problem at this time is that all bus branches have a short circuit fault.

[0062] Figure 3 A flow chart of a method for detecting a bus short circuit fault provided by an embodiment of the present disclosure, wherein the detection circuit comprises a first signal line, a second signal line, a power supply module, n external detection modules and n fault response modules; the external detection modules and the fault response modules are arranged in one-to-one correspondence with the branches of the bus; the branches of the bus are connected in parallel through the first signal line and the second signal line, the two detection ends of the n external detection modules are electrically connected to the first signal line and the second signal line respectively, the fault response module is connected in series with the first signal line and the second signal line, the n fault response modules are connected in parallel with each other, the external detection module is electrically connected to the fault response module, and the n external detection modules and the n fault response modules are all electrically connected to the power supply module; wherein n is an integer not less than 2; Figure 3 As shown, the detection method includes: S510, S520 and S530.

[0063] S510: Obtain the short circuit fault condition of any branch of the bus.

[0064] Specifically, each external detection module detects the short-circuit fault condition of each branch of the bus, thereby obtaining the short-circuit fault condition of any branch of the bus.

[0065] S520: Based on a short circuit fault occurring in any branch of the bus, control all fault response modules to cut off power supply to the branch of the bus where they are located, and control the external detection module to issue a fault prompt.

[0066] Specifically, when a short circuit occurs in any branch of the bus, all fault response modules cut off the power supply of the corresponding bus branch to the first signal line and the second signal line, and control the external detection module to issue a fault prompt to remind the staff of the short circuit.

[0067] S530: Based on the fact that no short circuit fault occurs in other branches of the bus, control the fault response module to restore power supply to other branches of the bus, and control the external detection module to stop issuing fault prompts.

[0068] Specifically, after all fault response modules cut off the power supply of the bus branches, the bus branches that have not suffered short-circuit faults will have their power restored by the fault response modules, but the bus branches that have suffered short-circuit faults will not have their power restored. Therefore, only the external detection module where the short-circuit fault has occurred will have a short-circuit fault prompt, while other external detection modules will stop issuing fault prompts because no short-circuit fault has occurred in their bus branches. As a result, the staff can determine the location of the bus branch where the short-circuit fault has occurred by the location of the external detection module that issued the fault prompt. The present invention thus achieves the ability to accurately and quickly determine the location of the bus branch where the short-circuit fault has occurred, thereby improving the detection efficiency of the bus short-circuit fault.

[0069] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0070] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bus short circuit fault detection circuit, characterized in that: include: A first signal line, a second signal line, a power supply module, n external detection modules, and n fault response modules; The external detection module and the fault response module are arranged in one-to-one correspondence with the branches of the bus; Each branch of the bus is connected in parallel through the first signal line and the second signal line, two detection ends of the n external detection modules are electrically connected to the first signal line and the second signal line respectively, the fault response module is connected in series with the first signal line and the second signal line, the n fault response modules are connected in parallel with each other, the external detection module is electrically connected to the fault response module, and the n external detection modules and the n fault response modules are all electrically connected to the power supply module; Wherein, n is an integer not less than 2; the external detection module is used to control the fault response module to cut off the connection between the first signal line and the second signal line and the branch of the bus according to a short circuit fault of any branch of the bus, and to prompt the occurrence of a fault; the power supply module is used to supply power to the external detection module and the fault response module; The fault response module is used to control the first signal line and the second signal line to be connected to the branch of the bus according to whether the branch of the bus has no short circuit fault after the connection is cut off.

2. The detection circuit according to claim 1, characterized in that: The external detection module includes two detection units and a first prompt unit; The detection end of one of the detection units is electrically connected to the first signal line, the detection end of the other detection unit is electrically connected to the second signal line, the output ends of the two detection units are electrically connected to the control end of the fault response module, and the output ends of the two detection units are also electrically connected to the control end of the first prompt unit.

3. The detection circuit according to claim 2, characterized in that: The detection unit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, a first pull-up resistor and a detection chip; The first signal line or the second signal line is electrically connected to the first end of the first voltage-dividing resistor, the second end of the first voltage-dividing resistor and the first end of the second voltage-dividing resistor are electrically connected to a first node, and the second end of the second voltage-dividing resistor is grounded; the first signal line or the second signal line is also electrically connected to the first end of the third voltage-dividing resistor, the second end of the third voltage-dividing resistor and the first end of the fourth voltage-dividing resistor are electrically connected to a second node, and the second end of the fourth voltage-dividing resistor is grounded; the first detection end of the detection chip is electrically connected to the first node, the second detection end of the detection chip is electrically connected to the second node, the power supply end of the detection chip is electrically connected to the power supply module, the first end of the detection chip is grounded, the first output end of the detection chip and the second output end of the detection chip are electrically connected to the power supply module through the first pull-up resistor, the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the fault response module, and the first output end of the detection chip and the second output end of the detection chip are also electrically connected to the control end of the first prompt unit.

4. The detection circuit according to claim 2, characterized in that: The first prompt unit includes a first diode; the positive terminal of the first diode is electrically connected to the power supply module, and the negative terminal of the diode is electrically connected to the output terminals of the two detection units.

5. The detection circuit according to claim 1, characterized in that: The fault response module includes a switch unit and a power supply recovery unit; Any branch of the bus is electrically connected to the first end of the switch unit through the first signal line, any branch of the bus is electrically connected to the second end of the switch unit through the second signal line, the third end of the switch unit is electrically connected to other branches of the bus through the first signal line, the fourth end of the switch unit is electrically connected to other branches of the bus through the second signal line, the control end of the switch unit is electrically connected to the output end of the external detection module, the first end of the power supply recovery unit is electrically connected to the corresponding first signal line, the second end of the power supply recovery unit is electrically connected to the corresponding second signal line, and the third end of the power supply recovery unit is electrically connected to the power supply module.

6. The detection circuit according to claim 5, characterized in that: The switch unit includes a relay, a second pull-up resistor, a PNP transistor, a second diode and a third diode; Any branch of the bus is electrically connected to the first end of the relay through the first signal line, any branch of the bus is electrically connected to the second end of the relay through the second signal line, the third end of the relay is electrically connected to other branches of the bus through the first signal line, the fourth end of the relay is electrically connected to other branches of the bus through the second signal line, the fifth end of the relay is grounded, the fifth end of the relay is also electrically connected to the positive end of the second diode, the negative end of the second diode is electrically connected to the sixth end of the relay, the negative end of the second diode is also electrically connected to the collector of the PNP transistor, the emitter of the PNP transistor is electrically connected to the power supply module, the base of the PNP transistor is electrically connected to the power supply module through the second pull-up resistor, the base of the PNP transistor is also electrically connected to the positive end of the third diode, and the negative end of the third diode is electrically connected to the output end of the external detection module.

7. The detection circuit according to claim 5, characterized in that: The power supply recovery unit includes a fifth voltage-dividing resistor, a sixth voltage-dividing resistor, a seventh voltage-dividing resistor and an eighth voltage-dividing resistor; The first end of the fifth voltage-dividing resistor is electrically connected to the power supply module, the second end of the fifth voltage-dividing resistor and the first end of the sixth voltage-dividing resistor are electrically connected to a third node, the second end of the sixth voltage-dividing resistor is grounded, the first end of the seventh voltage-dividing resistor is electrically connected to the power supply module, the second end of the seventh voltage-dividing resistor and the first end of the eighth voltage-dividing resistor are electrically connected to a fourth node, the second end of the eighth voltage-dividing resistor is grounded, the third node is electrically connected to the first signal line, and the fourth node is electrically connected to the second signal line.

8. The detection circuit according to any one of claims 1 to 7, characterized in that: Also included is an internal detection module; The first detection end of the internal detection module is electrically connected to the first signal line, the second detection end of the internal detection module is electrically connected to the second signal line, and the output end of the internal detection module is electrically connected to the control end of each of the fault response modules; wherein the internal detection module is used to control all of the fault response modules to cut off power supply to all branches of the bus according to the short-circuit fault conditions of the first signal line and the second signal line between the branches of the bus.

9. The detection circuit according to claim 8, characterized in that: The internal detection module also includes a bus power supply simulation unit; The input end of the bus-powered simulation unit is electrically connected to the power supply module, the first power supply end of the bus-powered simulation unit is electrically connected to the first signal line, and the second power supply end of the bus-powered simulation unit is electrically connected to the second signal line; wherein the bus-powered simulation unit is used to cut off the power supply of all branches of the bus according to the fault response module, and provide bus voltage for the first signal line and the second signal line.

10. A method for detecting a bus short circuit fault, characterized in that: The detection circuit includes a first signal line, a second signal line, a power supply module, n external detection modules and n fault response modules; the external detection modules and the fault response modules are arranged in one-to-one correspondence with the branches of the bus; the branches of the bus are connected in parallel through the first signal line and the second signal line, the two detection ends of the n external detection modules are electrically connected to the first signal line and the second signal line respectively, the fault response module is connected in series with the first signal line and the second signal line, the n fault response modules are connected in parallel with each other, the external detection module is electrically connected to the fault response module, and the n external detection modules and the n fault response modules are all electrically connected to the power supply module; wherein n is an integer not less than 2; The method comprises: Obtaining a short circuit fault condition of any branch of the bus; Based on a short circuit fault occurring in any branch of the bus, controlling all the fault response modules to cut off power supply to the branch of the bus where they are located, and controlling the external detection module to issue a fault prompt; Based on the fact that no short circuit fault occurs in other branches of the bus, the fault response module is controlled to restore power supply to other branches of the bus, and the external detection module is controlled to stop issuing fault prompts.

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