Bus short circuit fault detection circuit and method

Abstract

The present disclosure relates to a bus short-circuit fault detection circuit and method, the detection circuit comprising: a first signal line, a second signal line, a power supply module, n external detection modules, and n fault response modules; each branch of the bus is connected in parallel via the first signal line and the second signal line, the external detection module is electrically connected to the first signal line and the second signal line, the fault response module is connected in series with the first signal line and the second signal line, the external detection module is electrically connected to the fault response module, and the external detection module and the fault response module are electrically connected to the power supply module. The present disclosure controls each fault response module to cut off the power supply to each branch of the bus according to the occurrence of a short-circuit fault through the external detection module. After the power supply is cut off, the power supply to the bus branches that do not have a short-circuit fault is restored, and the external detection modules corresponding to the bus branches with a short-circuit fault issue a fault reminder, thereby allowing staff to accurately and quickly determine the location 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 circuit and method for detecting a bus short-circuit fault. Background Art

[0002] The CAN (Controller Area Network) bus, a serial communication bus, has been widely used to transmit data and control signals between various automotive electronic controllers. A CAN bus short circuit failure is typically caused by abrasion of the insulation layer of the CAN bus wiring harness, exposing the inner conductor and causing it to come into contact with other power lines, signal lines, or ground lines. This short circuit can cause the CAN bus voltage to be disturbed by external voltages, ultimately leading to CAN communication failures.

[0003] Existing techniques typically employ a serial troubleshooting approach. After a short circuit occurs, relays must be activated sequentially, starting from the nearest node on the CAN bus and progressing to the furthest node. This process takes longer as the number of CAN nodes increases. Therefore, how to quickly troubleshoot CAN bus short circuits has become a pressing technical challenge facing those skilled in the art. Summary of the Invention

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

[0005] The present disclosure provides a bus short-circuit fault detection circuit, 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; 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 configured to control the fault response module to cut off the connection between the first signal line and the second signal line and the bus branch according to the occurrence of a short-circuit fault in any branch of the bus, and to indicate the occurrence of a fault; the power supply module is configured to supply power to the external detection modules and the fault response modules; and the fault response module is configured to control the first signal line and the second signal line to conduct with the bus branch according to the absence of a short-circuit fault 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 to the 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, 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; 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 fault response module; wherein the internal detection module is used to control all fault response modules to cut off the 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 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 a 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, 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 includes: 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 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 no short-circuit fault occurring 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 bus short-circuit fault detection circuit and method, the detection circuit including a first signal line, a second signal line, a power supply module, n external detection modules, and n fault response modules, where n is an integer not less than 2. Since the bus branches 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. The external detection modules can detect short-circuit fault conditions of the corresponding bus branches. 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 the short-circuit fault and control the corresponding fault response modules to cut off the connection between the first signal line and the second signal line and the bus branches, thereby disconnecting the power supply from each bus branch 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 bus branch through each fault response module. The bus branch with the short circuit fault still has a voltage anomaly, while the other bus branches without the short circuit fault do not have a voltage anomaly. At this time, the fault response module corresponding to the bus branch without the voltage anomaly will restore the connection between the bus branch and the first signal line and the second signal line to restore power supply, while the bus branch with the voltage anomaly 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, all external detection modules will issue a fault prompt when the power supply is just cut off. However, 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. The other external detection modules will stop issuing fault prompts due to the restoration of power supply to the bus branch. Therefore, the present disclosure realizes that only the bus branch with the 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. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 1 A schematic structural diagram 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 flowchart of a bus short-circuit fault detection method provided in an embodiment of the present disclosure is provided. 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 in order to provide a comprehensive understanding of the present invention. However, it will be apparent 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 merely intended 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 with reference to the accompanying drawings.

[0022] Figure 1 A schematic diagram of a bus short circuit fault detection circuit according to 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 a 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, the 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. In addition, n external detection modules and n fault response modules are 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 occurring 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] For example, 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 disposed correspondingly to the first branch 410, the second external detection module 220 and the second fault response module 320 are disposed correspondingly to the second branch 420, and the third external detection module 230 and the third fault response module 330 are disposed correspondingly to the third branch 430. The first branch 410, the second branch 420, and the third branch 430 are connected in parallel via the first signal line 101 and the second signal line 102, while 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 terminal of the first external detection module 210 is electrically connected to the first signal line 101, and the second detection terminal of the first external detection module 210 is electrically connected to the second signal line 102. The first detection terminal of the second external detection module 220 is electrically connected to the first signal line 101, and the second detection terminal 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] Taking the short circuit fault of the first branch 410 as an example, when the short circuit fault 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 fault, and 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 the various fault response modules. Since the various fault response modules have disconnected the connections 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] Thus, the present disclosure detects short-circuit faults of corresponding bus branches through external detection modules. When a short-circuit fault occurs in a branch of the bus, the voltage of this branch will be abnormal, thereby causing abnormal voltages on the first signal line 101 and the second signal line 102. Therefore, all external detection modules will detect the occurrence of the short-circuit fault and control the corresponding fault response modules to cut off the connection between the first signal line 101 and the second signal line 102 and the bus branch, thereby disconnecting 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. 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 power supply, while the bus branch with the voltage abnormality will continue to remain disconnected. Furthermore, since the external detection modules issue corresponding fault prompts after detecting a short-circuit fault, all external detection modules will issue fault prompts immediately after power is cut off. However, when power is restored, only the external detection module corresponding to the bus branch experiencing the short-circuit fault will continue to issue fault prompts. The other external detection modules will stop issuing fault prompts due to the restoration of power to the bus branch. Thus, the present disclosure ensures that only the bus branch experiencing the short-circuit fault issues corresponding fault prompts, allowing personnel to quickly and accurately locate the bus branch experiencing the short-circuit fault, thereby improving the efficiency of bus short-circuit fault detection.

[0027] It should be noted that n being 3 is only an example, and n may also be another integer 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, and the detection end of the other detection unit is electrically connected to the second signal line, and 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 a first signal line, and the low-voltage signal line is electrically connected to a second signal line. When a short circuit 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 of the first signal line. When an overvoltage or undervoltage condition is detected in the first signal line, the first detection unit outputs a control signal through its output end, controlling the fault response module to disconnect the bus branch from the first and second signal lines and controlling the first notification unit to issue a fault notification. The second detection unit detects the voltage of the second signal line. When an overvoltage or undervoltage condition is detected in the second signal line, the second detection unit outputs a control signal through its output end, controlling the fault response module to disconnect the bus branch from the first and second signal lines and controlling the first notification unit to issue a fault notification. Therefore, when a short circuit fault occurs in either the high-voltage signal line or the low-voltage signal line of the bus, or both, the first detection unit will output a control signal based on the voltage condition of the first signal line, and the second detection unit will output a control signal based on the voltage condition of the second signal line. As a result, whenever a short circuit fault occurs in a bus branch, regardless of whether the high-voltage signal line or the low-voltage signal line is faulty, the fault response module will be controlled to disconnect the bus branch from the first signal line and the second signal line. Thus, by providing detection units for the first signal line and the second signal line, the present disclosure achieves separate detection of short circuit faults in the high-voltage signal line and the low-voltage signal line, thereby improving detection accuracy.

[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 to the 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, 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 terminal 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 terminal of the detection chip performs overvoltage detection on the voltage at the second node. When no short circuit fault occurs in the bus branch, the power supply module pulls up the first output terminal and the second output terminal of the detection chip to a high-level signal with a voltage of 5V through the first pull-up resistor, so that the control terminal 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 undervoltage, the voltage of the first signal line is lower than 2.375V. After the voltage is divided by the first and second voltage-dividing resistors, the first detection end of the detection chip detects that the voltage at the first node is lower than 0.3945V. The first output end of the detection chip then outputs a low-level signal, thereby causing the control end of the fault response module to receive the low-level signal. When the first signal line is overvoltage, the voltage of the first signal line is higher than 3.675V. The second detection end of the detection chip detects that the voltage at the second node is higher than 0.4V. The first output end of the detection chip then outputs a low-level signal, thereby causing the control end of the fault response module to receive the 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 undervoltage, the voltage of the second signal line is lower than 1.425V. After the voltage is divided by the first and second voltage-dividing resistors, the first detection end of the detection chip detects that the voltage at the first node is lower than 0.3945V. The first output end of the detection chip then outputs a low-level signal, thereby causing the control end of the fault response module to receive the low-level signal. When the second signal line is overvoltage, the voltage of the second signal line is higher than 2.625V. The second detection end of the detection chip detects that the voltage at the second node is higher than 0.4V. The first output end of the detection chip then outputs a low-level signal, thereby causing the control end of the fault response module to receive the low-level signal.

[0034] Thus, 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. Whenever either overvoltage or undervoltage occurs, the detection unit outputs a low-level signal to the control end of the fault response module, causing the fault response module to cut 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 again output a high-level signal to cause the fault response module to restore the connection between the bus branch and the signal line. This ensures that only the fault response module corresponding to the faulty bus branch remains in the state of disconnecting the bus branch from the signal line, allowing personnel to 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 divider resistor, the second voltage divider resistor, the third voltage divider resistor and the fourth voltage divider resistor are all examples. The specific signal line voltage and the resistance value of the voltage divider resistor 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. Therefore, at this time, the first diode is not conductive and does not emit light. When a short circuit fault occurs in the bus branch, the first detection unit outputs a low-level signal based on the short circuit fault of the high-voltage signal line of the bus, and the second detection unit outputs a low-level signal based on the short circuit fault of the low-voltage signal line of the bus. As a result, regardless of whether a short circuit fault occurs in the high-voltage signal line of the bus branch or the low-voltage signal line of the bus branch, the cathode end of the first diode will receive the low-level signal and conduct and emit light, thereby causing the first prompt unit to issue 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 a short circuit fault in a bus branch, the external detection module outputs a control signal to the control end of the switch unit, causing the switch unit to disconnect the bus branch from the first signal line and the second signal line, thereby disconnecting the bus branch from other bus branches. After all fault response modules have disconnected the bus branch from 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. Because 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 the 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 the short circuit fault can detect the short circuit fault, while the other external detection modules detect no abnormality. Therefore, at this time, only the external detection module corresponding to the bus branch with the short circuit fault issues a fault prompt, and only the switch unit corresponding to the bus branch with the short circuit fault is disconnected, while the switch units in the 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 terminal of the third diode and the anode terminal of the third diode are both high-level, so the third diode is not conducting, and 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 high-level signal received by the base. Since the PNP transistor is not conducting, no current flows between the fifth terminal of the relay and the sixth terminal of the relay, and the relay is in a conducting state, connecting the bus branch to the first signal line and the second signal line. When the external detection module detects that a short circuit fault has occurred in the bus branch, the output end of the external detection module outputs a low-level signal, the anode terminal of the third diode is high-level, so the third diode is conducting, the PNP transistor is turned on due to the low-level signal received by the base, and current flows between the fifth terminal of the relay and the sixth terminal of the relay, and the relay is in an off state, thereby achieving the goal of cutting off the connection between the bus branch and the first signal line and the second signal line through each relay after a short circuit fault occurs.

[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 of equal resistance, 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 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 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, allowing staff to 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; 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 fault response module; wherein the internal detection module is used to control all fault response modules to cut off the 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 occurs in all branches of the bus, all fault response modules disconnect each bus branch from the first and second signal lines, completely de-energizing the first and second signal lines within the detection circuit. Similarly, when a short circuit occurs within the detection circuit, the first and second signal lines within the detection circuit are also completely de-energized. Therefore, after the first and second signal lines within the detection circuit are de-energized, if the power supply to the first and second signal lines within the detection circuit is not restored to normal voltage, staff may mistakenly believe that a short circuit also exists within the detection circuit. Therefore, the present disclosure further includes a bus power supply simulation unit within the internal detection module. When the power is completely de-energized within the detection circuit, the bus power supply simulation unit begins to supply bus voltage to the first and second signal lines, thereby restoring the first and second signal lines within the detection circuit to normal voltage. All external detection modules and internal detection modules can then operate normally. At this point, only the location where the short circuit occurs issues a fault prompt, i.e., all external detection modules issue a fault prompt. This allows staff to quickly determine that the fault is a short circuit in all bus branches.

[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 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 via 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 is electrically connected to the first end of the second voltage-dividing resistor R2, 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 is electrically connected to the first end of the fourth voltage-dividing resistor R4, 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 positive 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 end 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 experiences an undervoltage, the voltage of the first signal line 101 is lower than 2.375V. After voltage division by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the first detection terminal of the detection chip U1 detects that the voltage at the first node A1 is lower than 0.3945V. The first output terminal of the detection chip U1 then outputs a low-level signal, causing the cathode terminal of the first diode D1 to receive the low-level signal, causing the first diode D1 to emit light. When an 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 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 to emit 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 experiences an undervoltage, the voltage of the second signal line 102 falls below 1.425V. After voltage division by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the first detection terminal of the detection chip U1 detects that the voltage at the first node A1 will fall below 0.3945V. The first output terminal of the detection chip U1 then outputs a low-level signal, causing the cathode terminal of the first diode D1 to receive the low-level signal, causing the first diode D1 to emit light. When an 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 to emit 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 divider resistor R1, the second voltage divider resistor R2, the third voltage divider resistor R3 and the fourth voltage divider resistor R4 are all examples. The specific signal line voltage and the resistance values ​​of the voltage divider resistors should be set according to the actual situation of the detection end of the detection chip U1, and no specific limitations are given 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 the other branches of the bus through the first signal line 101, the fourth end of the relay U2 is electrically connected to the 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, and 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 transistor Q1, the emitter of the PNP transistor Q1 is electrically connected to the power supply module 103, the base of the PNP transistor Q1 is electrically connected to the power supply module 103 through the second pull-up resistor R10, the base of the PNP 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 5V supply voltage, 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 of equal resistance, so the voltages at the third node A3 and the fourth node A4 are both 2.5V. After each relay U2 disconnects each bus branch from the first signal line 101 and the second signal line 102, the power supply module 103 provides 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 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 positive end of the third diode D3 are both high levels, so the third diode D3 is not conductive, 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 conductive, no current flows between the fifth end of the relay U2 and the sixth end of the relay U2, and the relay U2 is in the conductive 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 a short circuit fault has occurred in the bus branch 400, the output terminal of the detection chip U1 outputs a low-level signal, and the positive terminal of the third diode D3 is at a 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, current flows between the fifth terminal of the relay U2 and the sixth terminal of the relay U2, and the relay U2 is in the off state. When the internal detection module 104 detects that a short circuit fault exists within 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, thereby disconnecting all relays U2, and the internal detection module issues a fault prompt. As a result, the present disclosure implements that only the bus branch 400 that has a short circuit fault will issue a corresponding fault prompt, allowing staff to quickly and accurately 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.

[0059] It should be noted that the voltage of 5V provided by the power supply module 103 is only an example. 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 terminal of the internal detection module 104 is electrically connected to the first signal line 101, the second detection terminal of the internal detection module 104 is electrically connected to the second signal line 102, and the output terminal of the internal detection module 104 is electrically connected to the control terminal of each fault response module. The input terminal of the bus-powered simulation unit 105 is electrically connected to the power supply module 103, the first power supply terminal of the bus-powered simulation unit 105 is electrically connected to the first signal line 101, and the second power supply terminal of the bus-powered 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, completely de-energizing the first signal line 101 and the second signal line 102 within the detection circuit. Similarly, if a short circuit occurs within the detection circuit, the first signal line 101 and the second signal line 102 within the detection circuit will also be completely de-energized. Therefore, after the first signal line 101 and the second signal line 102 within the detection circuit are de-energized, if the power supply to the first signal line 101 and the second signal line 102 within the detection circuit is not restored to normal voltage, staff may mistakenly believe that a short circuit also exists within 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 issues a fault prompt, that is, all detection chips U1 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.

[0062] Figure 3 A flow chart of a bus short circuit fault detection method provided in an embodiment of the present disclosure, 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; the external detection modules and the fault response modules are arranged in a 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, 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 a 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 the short circuit fault occurs, and control the external detection module to issue a fault prompt.

[0066] Specifically, when a short circuit fault 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 fault.

[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 power restored by the fault response modules, but the bus branches that have suffered short-circuit faults will not have 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. Therefore, 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. Therefore, the present disclosure can 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 document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0070] The above are merely specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to these embodiments, but is to be construed in the broadest manner 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 a one-to-one correspondence with the branches of the bus; The branches of the bus are connected in parallel via 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 a short circuit fault occurring in any branch of the bus, and to indicate 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 after the connection is cut off and according to whether the branch of the bus where they are located has no short circuit fault.

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 is electrically connected to the first end of the fourth voltage-dividing resistor, 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 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 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 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, wherein: 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 the 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 various 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 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 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 the power supply of 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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