Alternating-current ring network fault finding system and method

Abstract

An alternating-current ring network fault finding system and method. The system comprises: a first alternating-current power supply module (10), a second alternating-current power supply module (20), a characteristic current signal generation module (30), and a characteristic current signal searching module (40); the characteristic current signal generation module (30) comprises a first control unit (31), a load control circuit (32) and a first wireless communication unit (33); the characteristic current signal searching module (40) comprises an instruction input unit (41), a current transformer (42), a second control unit (43) and a second wireless communication unit (44); a first end of the load control circuit (32) is connected to an A phase line, or a B phase line, or a C phase line, or a null line of the first alternating-current power supply module (10), and a second end thereof is connected to a ground wire of the first alternating-current power supply module (10); upon receiving an instruction output by the instruction input unit (41), the second control unit (43) sends a control instruction to the first control unit (31) by means of the wireless communication units (33, 44), such that the first control unit (31) controls, according to the control instruction, the load control circuit (32) to output characteristic current signals; the current transformer (42) detects characteristic current signals on phase lines and a null line of the second alternating-current power supply module (20); on the basis of the characteristic current signals detected by the current transformer (42), the second control unit (43) determines that a ring network fault occurs.

Description

AC ring network fault detection system and method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 1, 2023, with application number 202310960363.9. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the technical field of AC ring networks, for example, to an AC ring network fault finding system and method. Background Art

[0003] The substation AC system, also known as the station power system, is essential for ensuring the safe and reliable transmission of electrical energy within the substation. Station power primarily provides power for primary and secondary equipment within the substation, such as the forced oil circulation cooling system for large transformers, AC operating power, AC power for DC systems, AC power for heating, moisture control, and lighting, UPS and SF6 gas monitoring devices, exhaust fans for normal and emergency use, and lighting and other household power supplies.

[0004] A ring network fault in a station's power system can cause transformer overload, cable current overload, unreliable power supply to local equipment, and malfunction or failure of protective devices or power switching devices. In severe cases, this can cause a primary circuit failure, resulting in production hazards. An AC system ring network fault occurs when the feeders of two independently operating AC systems are incorrectly connected, resulting in a ring network current between the two systems. This ring network fault creates an imbalance in the three-phase currents of the two systems, which can severely lead to short circuits, malfunctioning protective devices, and other accidents, impacting system operation.

[0005] Currently, frontline power production personnel lack the equipment to find and troubleshoot AC system ring network faults online. They can only use the traditional method of shaking insulation during maintenance or power outage troubleshooting, which is inefficient and unsafe.

[0006] Summary of the Invention

[0007] The present application provides an AC ring network fault finding system and method to improve the efficiency of AC ring network fault finding.

[0008] In a first aspect, an embodiment of the present application provides an AC ring network fault finding system, the system comprising: a first AC power supply module, a second AC power supply module, a characteristic current signal generating module, and a characteristic current signal detecting module;

[0009] The characteristic current signal generating module includes a first control unit, a load control circuit and a first wireless communication unit; the characteristic current signal detecting module includes a command input unit, a current transformer, a second control unit and a second wireless communication unit; the load control circuit and the first wireless communication unit are electrically connected to the first control unit; the command input unit, the current transformer and the second wireless communication unit are electrically connected to the second control unit; the first wireless communication unit is communicatively connected to the second wireless communication unit;

[0010] The first end of the load control circuit is connected to the A phase line of the first AC power module, or the B phase line of the first AC power module, or the C phase line of the first AC power module, or the neutral line of the first AC power module; the second end of the load control circuit is connected to the ground line of the first AC power module;

[0011] The second control unit is configured to send a control instruction to the first control unit via the first wireless communication unit and the second wireless communication unit when receiving the instruction output by the instruction input unit;

[0012] The first control unit is configured to control the load control circuit to output a characteristic current signal according to the control instruction;

[0013] The current transformer is used to detect the characteristic current signal of each phase line of the second AC power supply module and the characteristic current signal of the neutral line of the second AC power supply module;

[0014] The second control unit is further used to determine whether a ring network fault occurs between the first AC power supply module and the second AC power supply module based on whether the current transformer detects the presence of a characteristic current signal on each phase line of the second AC power supply module, or whether the current transformer detects the presence of a characteristic current signal on the neutral line of the second AC power supply module.

[0015] Optionally, the load control circuit includes a control switch and a variable resistor; a first end of the control switch is connected to the A-phase line of the first AC power module, or to the B-phase line of the first AC power module, or to the C-phase line of the first AC power module, or to the neutral line of the first AC power module; a second end of the control switch is electrically connected to the first end of the variable resistor, and a second end of the variable resistor is connected to the ground line of the first AC power module;

[0016] The control switch is electrically connected to the first control unit; the first control unit is specifically configured to control the control switch to open at a variable frequency according to the control instruction so that the load control circuit outputs a characteristic current signal.

[0017] Optionally, the second control unit is further configured to send a resistance adjustment instruction to the first control unit via the first wireless communication unit and the second wireless communication unit upon receiving the resistance adjustment instruction output by the instruction output unit;

[0018] The first control unit is configured to control the variable resistor to adjust the resistance according to the resistance adjustment instruction so as to change the magnitude of the characteristic current signal output by the load control circuit.

[0019] Optionally, the characteristic current signal generating module further includes a first display unit; the first display unit is electrically connected to the first control unit;

[0020] The first control switch is further used to control the first display unit to display the characteristic current signal output by the load control circuit.

[0021] Optionally, the characteristic current signal exploration module includes a second display unit;

[0022] The second display unit is electrically connected to the second control unit;

[0023] The second control unit is used to control the second display unit to display the characteristic current signal on each phase line of the second AC power supply module detected by the current transformer, or the characteristic current signal on the neutral line of the second AC power supply module detected by the current transformer.

[0024] Optionally, the system further includes: a first bonding wire; one end of the first bonding wire is bonded to the A-phase line of the second AC power module, the B-phase line of the second AC power module, the C-phase line of the second AC power module, and the neutral line of the second AC power module; the other end of the first bonding wire extends outward in a direction perpendicular to the A-phase line of the second AC power module, the B-phase line of the second AC power module, the C-phase line of the second AC power module, and the neutral line of the second AC power module;

[0025] It also includes a second bonding wire; one end of the second bonding wire is bonded to the A-phase wire of the first AC power module, the B-phase wire of the first AC power module, the C-phase wire of the first AC power module, and the neutral wire of the first AC power module; the other end of the second bonding wire extends outward in a direction perpendicular to the A-phase wire of the first AC power module, the B-phase wire of the first AC power module, the C-phase wire of the first AC power module, and the neutral wire of the first AC power module;

[0026] When a ring network failure occurs between the first AC power module and the second AC power module, the first jumper wire is connected to the second jumper wire;

[0027] The current transformer is further used to detect characteristic current signals at a first position and a second position on the first bonding wire;

[0028] The second control unit is further configured to determine a ring network fault point based on a characteristic current signal at a first position on the bonding wire and a characteristic current signal at a second position on the bonding wire.

[0029] Optionally, the second control unit is further used to determine that when there is no characteristic current signal at the first position on the first jumper wire, and when there is the characteristic current signal at the second position on the first jumper wire, the ring network fault point is between the first position on the first jumper wire and the second position on the first jumper wire.

[0030] Optionally, the characteristic current signal detection module includes an amplification circuit;

[0031] The amplifying circuit is electrically connected to the current transformer and the second control unit; the amplifying circuit is used to amplify the characteristic current signal detected by the current transformer and output it to the second control unit.

[0032] Optionally, the control switch includes an electromagnetic relay.

[0033] In a second aspect, an embodiment of the present application further provides an AC ring network fault locating method, which is applied to the AC ring network fault locating system described in the first aspect above; the AC ring network fault locating method includes:

[0034] When the second control unit receives the instruction output by the instruction output unit, it sends the control instruction to the first control unit through the first wireless communication unit and the second wireless communication unit;

[0035] The first control unit controls the load control circuit to output a characteristic current signal according to the control instruction;

[0036] The current transformer detects characteristic current signals on each phase line of the second AC power supply module and detects characteristic current signals at each position on the neutral line of the second AC power supply module;

[0037] The second control unit determines whether a ring network fault occurs between the first AC power module and the second AC power module based on whether the current transformer detects a characteristic current signal on each phase line of the second AC power module, or whether the current transformer detects a characteristic current signal on the neutral line of the second AC power module.

[0038] In an embodiment of the present application, when the second control unit receives the instruction output by the instruction input unit, it sends a control instruction to the first control unit through the first wireless communication unit and the second wireless communication unit; the first control unit controls the load control circuit to output a characteristic current signal according to the control instruction; the current transformer detects the characteristic current signal on each phase line of the second AC power supply module and detects the characteristic current signal on the neutral line of the second AC power supply module; the second control unit determines that a ring network fault has occurred between the first AC power supply module and the second AC power supply module when it determines that the current transformer detects the presence of a characteristic current signal on each phase line of the second AC power supply module, or that the current transformer detects the presence of a characteristic current signal on the neutral line of the second AC power supply module, thereby improving the efficiency of AC ring network fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic structural diagram of an AC ring network fault finding system provided in an embodiment of the present application;

[0040] FIG2 is a schematic diagram of the specific structure of an AC ring network fault finding system provided in an embodiment of the present application;

[0041] FIG3 is a schematic diagram of the specific structure of another AC ring network fault finding system provided in an embodiment of the present application;

[0042] FIG4 is a schematic diagram of the specific structure of another AC ring network fault finding system provided in an embodiment of the present application;

[0043] FIG5 is a flow chart of an AC ring network fault locating method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present application and are not intended to limit the present application. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions of the present application, not all of the structures.

[0045] FIG1 is a structural diagram of an AC ring network fault finding system provided by an embodiment of the present application. As shown in FIG1 , the system includes: a first AC power supply module 10, a second AC power supply module 20, a characteristic current signal generating module 30 and a characteristic current signal detecting module 40; the characteristic current signal generating module 30 includes a first control unit 31, a load control circuit 32 and a first wireless communication unit 33; the characteristic current signal detecting module 40 includes an instruction input unit 41, a current transformer 42, a second control unit 43 and a second wireless communication unit 44; the load control circuit 32 and the first wireless communication unit 33 are connected to the first wireless communication unit 33. A control unit 31 is electrically connected; the instruction input unit 41, the current transformer 42, and the second wireless communication unit 44 are electrically connected to the second control unit 43; the first wireless communication unit 33 is communicatively connected to the second wireless communication unit 44; the first end of the load control circuit 32 is connected to the A phase line of the first AC power module, or to the B phase line of the first AC power module (not shown in the figure), or to the C phase line of the first AC power module (not shown in the figure), or to the neutral line N of the first AC power module (not shown in the figure); the second end of the load control circuit 32 is connected to the ground line PE of the first AC power module;

[0046] The second control unit 43 is configured to send a control instruction to the first control unit 31 via the first wireless communication unit 33 and the second wireless communication unit 44 upon receiving the instruction output by the instruction input unit 41;

[0047] A first control unit 31 is used to control the load control circuit 32 to output a characteristic current signal according to a control instruction;

[0048] The current transformer 42 is used to detect the characteristic current signal on each phase line of the second AC power supply module 20 and the characteristic current signal on the neutral line of the second AC power supply module 20; the second control unit 43 is also used to determine whether a ring network fault occurs between the first AC power supply module 10 and the second AC power supply module 20 based on whether the current transformer 42 detects the presence of characteristic current signals on each phase line of the second AC power supply module 20, or whether the current transformer 42 detects the presence of characteristic current signals on the neutral line of the second AC power supply module.

[0049] In the related art, the first AC power module 10 and the second AC power module 20 are independently operated modules; the three-phase current of each AC power module 10 is kept balanced; if any feeder (A phase line, B phase line, C phase line and N neutral line) of the first AC power module 10 is incorrectly connected to any feeder phase line (A phase line, B phase line, C phase line and N neutral line) of the second AC power module 20, an AC ring network fault will occur. Common AC ring network faults include same-phase ring network faults and different-phase ring network faults; a same-phase ring network fault is when the A phase line, B phase line, C phase line and N neutral line of the two AC power modules are incorrectly connected one by one; illustratively, the A phase line of the first AC power module 10 is incorrectly connected to the A phase line of the second AC power module 20; a different-phase ring network fault is when the different phase lines of the two AC power modules are incorrectly connected; illustratively, the A phase line of the first AC power module 10 is incorrectly connected to the B, C phase lines and N neutral line of the second AC power module 20;

[0050] In this embodiment, upon receiving the fault-finding instruction output by the instruction input unit 41, the second control unit 43 sends a control instruction to the first control unit 31 via the first wireless communication unit 33 and the second wireless communication unit 44. The first control unit 31 controls the load control circuit 32 to output a characteristic current signal according to the control instruction. If the A phase line of the first AC power module 10 is connected to the phase lines and the neutral line of the second AC power module 20, then, according to the current shunt principle, a portion of the characteristic current signal generated by the load control circuit 32 will flow into the A phase line of the first AC power module 10 and flow back to the second end of the load control circuit 32 through the PE ground line of the first AC power module 10; the other portion will flow into the A phase line (or the B phase line, the B phase line and the N neutral line) of the second AC power module 20 and flow back to the second end of the load control circuit 32 through the PE ground line of the second AC power module 20. In this embodiment, after the load control circuit 32 outputs the characteristic current signal, there is no need to inject characteristic current signals of different frequencies into the AC power module itself. The characteristic current signals and detection signals on the phase lines of the second AC power module 20 are further detected by the current transformer 42. The characteristic current signal on the neutral line of the second AC power module; the second control unit 43 determines that a ring network fault occurs between the first AC power module and the second AC power module when it determines that the current transformer 42 detects the presence of a characteristic current signal on each phase line of the second AC power module, or the current transformer 42 detects the presence of a characteristic current signal on the neutral line of the second AC power module. Specifically, the second control unit 43 determines that a same-phase ring network fault occurs between the first AC power module and the second AC power module when it determines that the current transformer 42 detects the presence of a characteristic current signal on the A phase line of the second AC power module; the second control unit 43 determines that a different-phase ring network fault occurs between the first AC power module and the second AC power module when it determines that the current transformer 42 detects the presence of a characteristic current signal on the B phase line, the C phase line and the N neutral line of the second AC power module; and the second control unit 43 determines that no ring network fault occurs between the first AC power module and the second AC power module when it determines that the current transformer 42 does not detect the presence of a characteristic current signal on each phase line of the second AC power module, or the current transformer 42 does not detect the presence of a characteristic current signal on the neutral line of the second AC power module.

[0051] It is understandable that the first end of the load control circuit 32 can also be connected to the B phase line of the first AC power module, or to the C phase line of the first AC power module, or to the neutral line N of the first AC power module; in this way, when the load control circuit 32 is controlled to output the characteristic current signal, the current transformer 42 detects the characteristic current signals on each phase line of the second AC power module and detects the characteristic current signal on the neutral line of the second AC power module; the second control unit 43 determines that a ring network fault has occurred between the first AC power module and the second AC power module when it determines that the current transformer 42 detects the presence of characteristic current signals on each phase line of the second AC power module, or the current transformer 42 detects the presence of characteristic current signals on the neutral line of the second AC power module; in this way, the efficiency of AC ring network fault detection is improved by sequentially setting the load control circuit 32 on different phase lines and neutral lines of the first AC power module, and then the current transformer 42 detects the characteristic current signals of each phase line and neutral line of the second AC power module.

[0052] Optionally, Figure 2 is a specific structural diagram of an AC ring network fault finding system provided in an embodiment of the present application. As shown in Figure 2, the load control circuit 32 includes a control switch K and a variable resistor R; the first end of the control switch K is connected to the A phase line of the first AC power module, or to the B phase line of the first AC power module, or to the C phase line of the first AC power module, or to the neutral line of the first AC power module; the second end of the control switch K is electrically connected to the first end of the variable resistor R, and the second end of the variable resistor R is connected to the ground line of the first AC power module; the control switch K is electrically connected to the first control unit 31; the first control unit 31 is specifically used to control the control switch K to open at a variable frequency according to the control instruction so that the load control circuit 32 outputs a characteristic current signal.

[0053] The control switch K includes an electromagnetic relay. The first control unit 31 controls the control switch K to open at a variable frequency according to a control instruction. Utilizing the potential difference between the phase A line and the ground line PE, the variable resistor R outputs a characteristic current signal, which is a regular square wave current signal. In some embodiments, if the characteristic current signal detected by the current transformer 42 is weak and difficult to distinguish, the user can input a resistance adjustment instruction to the instruction output unit 41. Upon receiving the resistance adjustment instruction output by the instruction output unit 41, the second control unit 43 transmits a resistance adjustment instruction to the first control unit 31 via the first wireless communication unit 33 and the second wireless communication unit 44. The first control unit 31 then controls the variable resistor R to reduce its resistance according to the resistance adjustment instruction, thereby increasing the magnitude of the characteristic current signal output by the load control circuit 32.

[0054] Optionally, FIG3 is a schematic diagram of the specific structure of another AC ring network fault finding system provided in an embodiment of the present application. As shown in FIG3 , the characteristic current signal generating module 30 further includes a first display unit 34. The first display unit 34 is electrically connected to the first control unit 31. The first control unit 31 is further configured to control the first display unit 34 to display the characteristic current signal output by the load control circuit 32. The provision of the first display unit 34 enables human-computer interaction and improves the convenience of the AC ring network.

[0055] Optionally, referring to FIG. 3 , the characteristic current signal search module 40 includes a second display unit 45 ; the second display unit 45 is electrically connected to a second control unit 43 ; the second control unit 43 is configured to control the second display unit to display the characteristic current signal detected by the current transformer 42 on each phase line of the second AC power module, or the characteristic current signal detected by the current transformer 42 on the neutral line of the second AC power module. The provision of the second display unit 34 enables human-computer interaction and improves the convenience of the AC ring network.

[0056] Optionally, referring again to FIG3 , the characteristic current signal detection module 40 includes an amplifying circuit 46 ; the amplifying circuit 46 is electrically connected to the current transformer 42 and the second control unit 43 ; the amplifying circuit 46 is configured to amplify the characteristic current signal detected by the current transformer 42 and output it to the second control unit 43 . The provision of the amplifying circuit 46 can improve the reliability of the second control unit 43 in determining the AC ring network.

[0057] Optionally, Figure 4 is a structural diagram of another AC ring network fault finding system provided in an embodiment of the present application; as shown in Figure 4, it also includes: a first bonding wire L1; one end of the first bonding wire L1 is bonded to the A phase line of the second AC power module, the B phase line of the second AC power module, the C phase line of the second AC power module, and the neutral line of the second AC power module; the other end of the first bonding wire L1 extends outward in a direction perpendicular to the A phase line of the second AC power module, the B phase line of the second AC power module, the C phase line of the second AC power module, and the neutral line of the second AC power module;

[0058] It also includes a second bonding wire L2; one end of the second bonding wire L2 is bonded to the A-phase line of the first AC power module, the B-phase line of the first AC power module, the C-phase line of the first AC power module, and the neutral line of the first AC power module; the other end of the second bonding wire L2 extends outward in a direction perpendicular to the A-phase line of the first AC power module, the B-phase line of the first AC power module, the C-phase line of the first AC power module, and the neutral line of the first AC power module;

[0059] When a ring network fault occurs between the first AC power module 10 and the second AC power module 20, the first jumper L1 is connected to the second jumper L2; the current transformer 42 is also used to detect the characteristic current signals at the first position A and the second position B on the first jumper L1; the second control unit 43 is also used to determine the ring network fault point based on the characteristic current signal at the first position A on the first jumper L1 and the characteristic current signal at the second position B on the first jumper L1.

[0060] Among them, since the second position A on the first bonding wire L1 is outside the AC ring network, the second control unit 43 specifically determines that when there is no characteristic current signal at the first position A on the first bonding wire L1 and when there is a characteristic current signal at the second position B on the first bonding wire L1, the ring network fault point is between the first position A on the first bonding wire L1 and the second position B on the bonding wire. In this way, this embodiment further achieves the effect of finding the ring network fault point on the basis of the above embodiment.

[0061] The present application also provides an AC ring network fault locating method, which is applied to the AC ring network fault locating system described in the above embodiment. FIG5 is a flow chart of an AC ring network fault locating method provided by the present application. As shown in FIG5 , the AC ring network fault locating method includes:

[0062] S110 , when receiving the instruction output by the instruction output unit, the second control unit sends the control instruction to the first control unit through the first wireless communication unit and the second wireless communication unit.

[0063] S120. The first control unit controls the load control circuit to output a characteristic current signal according to the control instruction.

[0064] S130 : The current transformer detects characteristic current signals on each phase line of the second AC power supply module and detects characteristic current signals at each position on the neutral line of the second AC power supply module.

[0065] S140. The second control unit determines whether a ring network fault occurs between the first AC power module and the second AC power module based on whether the current transformer detects characteristic current signals on the phase lines of the second AC power module, or whether the current transformer detects characteristic current signals on the neutral line of the second AC power module.

[0066] In this embodiment, the second control unit determines that a current transformer detects the presence of a characteristic current signal on each phase line of the second AC power supply module, or that the current transformer detects the presence of a characteristic current signal on the neutral line of the second AC power supply module, thereby determining that a ring network fault has occurred between the first AC power supply module and the second AC power supply module, thereby improving the efficiency of AC ring network fault detection.

Claims

1. An AC ring network fault finding system, comprising: A first AC power supply module, a second AC power supply module, a characteristic current signal generating module and a characteristic current signal searching module; The characteristic current signal generating module includes a first control unit, a load control circuit and a first wireless communication unit; the characteristic current signal detecting module includes a command input unit, a current transformer, a second control unit and a second wireless communication unit; the load control circuit and the first wireless communication unit are electrically connected to the first control unit; the command input unit, the current transformer and the second wireless communication unit are electrically connected to the second control unit; the first wireless communication unit is in communication connection with the second wireless communication unit; The first end of the load control circuit is connected to the A phase line of the first AC power module, or the B phase line of the first AC power module, or the C phase line of the first AC power module, or the neutral line of the first AC power module; the second end of the load control circuit is connected to the ground line of the first AC power module; The second control unit is used to send a control instruction to the first control unit through the first wireless communication unit and the second wireless communication unit when receiving the instruction output by the instruction input unit; The first control unit is used to control the load control circuit to output a characteristic current signal according to the control instruction; The current transformer is used to detect the characteristic current signal on each phase line of the second AC power supply module and the characteristic current signal on the zero line of the second AC power supply module; The second control unit is further used to determine whether a ring network fault occurs between the first AC power supply module and the second AC power supply module based on whether the current transformer detects the presence of a characteristic current signal on each phase line of the second AC power supply module, or whether the current transformer detects the presence of a characteristic current signal on the neutral line of the second AC power supply module.

2. The AC ring network fault finding system according to claim 1, wherein: The load control circuit includes a control switch and a variable resistor; a first end of the control switch is connected to the A phase line of the first AC power module, or to the B phase line of the first AC power module, or to the C phase line of the first AC power module, or to the neutral line of the first AC power module; a second end of the control switch is electrically connected to the first end of the variable resistor, and a second end of the variable resistor is connected to the ground line of the first AC power module; The control switch is electrically connected to the first control unit; the first control unit is specifically used to control the control switch to open at a variable frequency according to the control instruction so that the load control circuit outputs a characteristic current signal.

3. The AC ring network fault finding system according to claim 2, wherein: The second control unit is further configured to send the resistance adjustment instruction to the first control unit through the first wireless communication unit and the second wireless communication unit when receiving the resistance adjustment instruction output by the instruction output unit; The first control unit is used to control the variable resistor to adjust the resistance according to the resistance adjustment instruction so as to change the size of the characteristic current signal output by the load control circuit.

4. The AC ring network fault finding system according to claim 1, wherein: The characteristic current signal generating module further includes a first display unit; the first display unit is electrically connected to the first control unit; The first control switch is further used to control the first display unit to display the characteristic current signal output by the load control circuit.

5. The AC ring network fault finding system according to claim 1, wherein: The characteristic current signal exploration module includes a second display unit; The second display unit is electrically connected to the second control unit; The second control unit is used to control the second display unit to display the characteristic current signal on each phase line of the second AC power supply module detected by the current transformer, or the characteristic current signal on the neutral line of the second AC power supply module detected by the current transformer.

6. The AC ring network fault finding system according to claim 1, further comprising: First lap wire; One end of the first bonding wire is bonded to the A-phase wire of the second AC power module, the B-phase wire of the second AC power module, the C-phase wire of the second AC power module, and the neutral wire of the second AC power module; the other end of the first bonding wire extends outward in a direction perpendicular to the A-phase wire of the second AC power module, the B-phase wire of the second AC power module, the C-phase wire of the second AC power module, and the neutral wire of the second AC power module; It also includes a second bonding wire; one end of the second bonding wire is bonded to the A phase line of the first AC power module, the B phase line of the first AC power module, the C phase line of the first AC power module, and the neutral line of the first AC power module; the other end of the second bonding wire extends outward in a direction perpendicular to the A phase line of the first AC power module, the B phase line of the first AC power module, the C phase line of the first AC power module, and the neutral line of the first AC power module; When a ring network failure occurs between the first AC power module and the second AC power module, the first bonding wire is connected to the second bonding wire; The current transformer is also used to detect characteristic current signals at a first position and a second position on the first bonding wire; The second control unit is further used to determine the ring network fault point according to the characteristic current signal at the first position on the bonding wire and the characteristic current signal at the second position on the bonding wire.

7. The AC ring network fault finding system according to claim 6, wherein: The second control unit is further used to determine that when there is no characteristic current signal at the first position on the first bonding wire and when there is the characteristic current signal at the second position on the first bonding wire, the ring network fault point is between the first position on the first bonding wire and the second position on the bonding wire.

8. The AC ring network fault finding system according to claim 2, wherein: The characteristic current signal detection module includes an amplification circuit; The amplifier circuit is electrically connected to the current transformer and the second control unit; the amplifier circuit is used to amplify the characteristic current signal detected by the current transformer and output it to the second control unit.

9. The AC ring network fault finding system according to claim 2, wherein: The control switch includes an electromagnetic relay.

10. An AC ring network fault finding method, applied to the AC ring network fault finding system according to any one of claims 1 to 9; the AC ring network fault finding method comprising: When the second control unit receives the instruction output by the instruction output unit, it sends the control instruction to the first control unit through the first wireless communication unit and the second wireless communication unit; The first control unit controls the load control circuit to output a characteristic current signal according to the control instruction; The current transformer detects characteristic current signals on each phase line of the second AC power supply module and detects characteristic current signals at each position on the neutral line of the second AC power supply module; The second control unit determines whether a ring network fault occurs between the first AC power supply module and the second AC power supply module based on whether the current transformer detects a characteristic current signal on each phase line of the second AC power supply module, or whether the current transformer detects a characteristic current signal on the neutral line of the second AC power supply module.

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