A three-core cable inter-core short circuit and incomplete conduction fault simulation device and fault identification method

Abstract

The application discloses a kind of three-core cable inter-core short circuit and incomplete conduction fault simulation device and fault identification method.The device is driven by paw finger, telescopic conduction track and variable resistance through stepper motor and gear transmission mechanism, realize the controllable simulation of high / low resistance short circuit between electric core a-b, a-c, b-c, and utilize sector connecting disc to adjust electric core contact area to simulate different degrees of incomplete conduction fault, can be set in a variety of mixed faults in cable along line N node combination.The method uses single-end injection linear frequency modulation signal and carries out matched filter processing, realizes fault positioning based on reflection peak time delay, constructs modal coupling factor, amplitude ratio and high-frequency energy proportion by modal decoupling characteristic quantity, realizes the identification of high resistance short circuit, low resistance short circuit and incomplete conduction fault, and further determines specific short circuit core pair.The technology does not need remote synchronous equipment, positioning accuracy is high, anti-interference ability is strong, and is suitable for the on-line / off-line operation and maintenance of three-core cable in the field of electric power, rail transit and new energy.

Description

Technical Field

[0001] This application relates to the field of power equipment fault diagnosis technology, specifically to a device for simulating short circuits and incomplete conduction faults between cores of a three-core cable and a fault identification method. Background Technology

[0002] Three-core cables are widely used in power, rail transportation, shipbuilding, and new energy equipment, serving as a crucial carrier for energy and control signal transmission. During long-term service, they are susceptible to hidden defects such as high / low resistance short circuits between cores and incomplete conduction due to mechanical stress, temperature rise aging, humidity, and chemical corrosion. These faults initially manifest as minute changes in local impedance; if not detected promptly, they can progress to breakdown, overheating, and even power outages. Existing cable fault detection technologies mainly include time-domain reflectometry (TDR), frequency-domain impedance spectroscopy, and DC bridge methods. TDR is simple in structure but lacks the ability to distinguish multiple fault points, making it difficult to differentiate adjacent reflections and identify specific short-circuited core pairs. Frequency-domain methods are sensitive to grounding conditions and load states, limiting their online application. Traditional impedance methods can only provide overall resistance values ​​and cannot achieve spatial location and fault type identification. Linear frequency modulation (LFM) pulse compression technology offers advantages such as concentrated energy, high distance resolution, and strong noise immunity, making it suitable for refined inspection of long-distance cables. However, current research on LFM (Low-Fault Mechanism) mainly focuses on single-core or two-core structures, lacking a systematic model for three-core cables with single-end injection and multiple simultaneous fault points. Furthermore, the mechanism for distinguishing between "incomplete continuity faults" and "high-resistance short circuits" is still incomplete, making it difficult to determine which two specific cores are short-circuited. Therefore, there is an urgent need for a three-core cable detection method based on single-end LFM injection that can accurately locate, classify, and determine the short-circuited core pairs of N mixed fault points along the cable without relying on remote equipment, to meet the dimensional requirements of complex engineering scenarios. Summary of the Invention

[0003] The purpose of this invention is to provide a device and method for simulating short circuits and incomplete continuity faults between cores of a three-core cable, and to calculate fault detection indicators to achieve fault identification and location at multiple locations in the cable.

[0004] To achieve the above technical objectives, this invention provides a device for simulating short circuits and incomplete conduction faults between the cores of a three-core cable. The device uses a mechanical apparatus to simulate the fault and includes: a three-core cable (1), core a (2), core b (3), core c (4), a mechanical support platform (5), a cable bracket a (6) connected to the mechanical support platform, a mechanical device bracket a (7) connected to the mechanical support platform, a mechanical device bracket b (8) connected to the mechanical support platform, a mechanical device bracket c (9) connected to the mechanical support platform, a mechanical device bracket d (10) connected to the mechanical support platform, a cable bracket b (11) connected to the mechanical support platform, and a star-shaped core fixing bracket a (12) coaxial with the cable and correspondingly connected to cores a, b, and c. 12) A battery core fixing ring a connected to the star-shaped battery core fixing bracket a (13) A star-shaped battery core fixing bracket b coaxial with the cable and correspondingly connected to battery cores a, b, and c (14) A battery core fixing ring b connected to the star-shaped battery core fixing bracket b (15) A threaded rod a connected to the battery core fixing rings a and b at its head and end respectively (16) A threaded rod b connected to the battery core fixing rings a and b at its head and end respectively and fixed on mechanical device brackets a and b (17) A threaded rod c connected to the battery core fixing rings a and b at its head and end respectively and fixed on mechanical device brackets c and d (18) A butterfly nut a connected to the head of threaded rod a (19) A butterfly nut b connected to the head of threaded rod b (20) ), a butterfly nut c connected to the beginning of the threaded rod c (21), an LFM excitation signal generation unit connected to the beginning of the cable (22), an echo detection and modulation unit connected to the beginning of the cable (23), a motor support platform a connected to the battery core fixing ring a (24), a motor support platform b connected to the battery core fixing ring a (25), a motor support platform c connected to the battery core fixing ring a (26), a stepper motor a connected to the motor support platform a (27), a stepper motor b connected to the motor support platform b (28), a stepper motor c connected to the motor support platform c (29), a battery core bracket a connected to the battery core a (30), a battery core bracket b connected to the battery core b (31), and a battery core bracket c connected to the battery core c (32). 1. Primary gear a connected to stepper motor a (33), primary gear b connected to stepper motor b (34), primary gear c connected to stepper motor c (35), secondary gear a meshing with primary gear a (36), secondary gear b meshing with primary gear b (37), secondary gear c meshing with primary gear c (38), claw connecting rod a connected to primary gear a (39), claw a connected to claw connecting rod a (40), claw connecting rod b connected to secondary gear a (41), claw b connected to claw connecting rod b (42), claw connecting rod c connected to primary gear b (43), claw c connected to claw connecting rod c (44), claw connecting rod d connected to secondary gear b (45)Claw d (46) connected to claw connecting rod d, claw connecting rod e (47) connected to first-stage gear c, claw e (48) connected to claw connecting rod e, claw connecting rod f (49) connected to second-stage gear c, claw f (50) connected to claw connecting rod f, variable resistor a (51) fixed on the cell fixing ring between cells a and b, variable resistor b (52) fixed on the cell fixing ring between cells b and c, and variable resistor b (53) fixed on the cell fixing ring between cells c and a. The variable resistor c (53) on the fixed ring, the telescopic conductive track a (54) connected to and fixed on the battery cell fixed ring, the telescopic conductive track b (55) connected to and fixed on the battery cell fixed ring, the telescopic conductive track c (56) connected to and fixed on the battery cell fixed ring, the fan-shaped rotating track (57) connected to the main shaft of the star-shaped telecommunications fixed bracket b, the fan-shaped connecting plate a (58) fitted with the fan-shaped rotating track, and the fan-shaped connecting plate fitted with the fan-shaped rotating track. b (59), fan-shaped connecting plate c (60) fitted with fan-shaped rotating track, rotating rod a (61) connected to fan-shaped connecting plate a, rotating rod b (62) connected to fan-shaped connecting plate b, rotating rod c (63) connected to fan-shaped connecting plate c, battery cell bracket d (64) connected to battery cell a, battery cell bracket e (65) connected to battery cell a, battery cell bracket f (66) connected to battery cell a, stepper motor d (67) on battery cell bracket d, stepper motor e (68) on battery cell bracket e, stepper motor f (69) on battery cell bracket f, primary gear d (70) connected to stepper motor d, primary gear e (71) connected to stepper motor e, primary gear f (72) connected to stepper motor f, secondary gear d (73) coaxial with rotating rod a and meshing with primary gear d, secondary gear e (74) coaxial with rotating rod b and meshing with primary gear e, secondary gear f (75) coaxial with rotating rod c and meshing with primary gear f.

[0005] The device can handle high and low resistance short-circuit faults between battery cells and incomplete cell conduction faults, including:

[0006] (1) Drive stepper motor a (27) to drive first gear a (33) to rotate clockwise, and further drive second gear a (36) to rotate counterclockwise, so that claw connecting rod a (39) and claw connecting rod b (41) rotate relative to each other, and further drive claw a (40) and claw b (42) to squeeze the head end of telescopic conductive rail a (54) and the tail end of telescopic conductive rail b (55) until they are closed and connected with variable resistor a (51) to realize the short circuit fault setting between cell a and b. By changing the resistance value of variable resistor a (51), high and low resistance short circuit faults can be set.

[0007] (2) Drive the stepper motor b (28) to drive the first gear b (34) to rotate clockwise, and further drive the second gear b (37) to rotate counterclockwise, so that the claw connecting rod c (43) and the claw connecting rod d (45) rotate relative to each other, and further drive the claw c (44) and the claw d (46) to squeeze the head end of the telescopic conductive rail b (55) and the tail end of the telescopic conductive rail c (56) until they are closed and connected with the variable resistor b (52) to realize the short circuit fault setting between the battery cells b and c. By changing the resistance value of the variable resistor b (52), high and low resistance short circuit faults can be set.

[0008] (3) Drive the stepper motor c (29) to drive the first gear c (35) to rotate clockwise, and further drive the second gear c (38) to rotate counterclockwise, so that the claw connecting rod e (47) and claw connecting rod f (49) rotate relative to each other, and further drive the claw e (48) and claw f (50) to squeeze the head end of the telescopic conductive rail c (56) and the tail end of the telescopic conductive rail a (54) until they are closed and connected with the variable resistor c (53) to realize the short circuit fault setting between the battery cell a and c. By changing the resistance value of the variable resistor c (53), high and low resistance short circuit faults can be set.

[0009] (4) Drive the stepper motor d (67) to rotate clockwise and drive the first gear d (70) to rotate counterclockwise, which in turn drives the second gear d (73) to rotate clockwise. Through the rotation rod a (61), the sector-shaped connecting plate a (58) rotates clockwise along the sector-shaped rotating track (57) to change the relative position relationship between the round hole on the sector-shaped connecting plate a (58) and the battery cell a (2), thus achieving an incomplete conduction fault. When the round hole and the battery cell a (2) are completely aligned, it is a completely non-conducting fault.

[0010] (5) Drive the stepper motor e (68) to rotate the first gear e (71) clockwise and rotate it counterclockwise, which in turn drives the second gear e (74) to rotate clockwise. Through the rotation rod b (61), the sector connecting plate b (59) rotates clockwise along the sector rotating track (57) to change the relative position relationship between the round hole on the sector connecting plate b (59) and the battery cell b (3) to achieve incomplete conduction fault. When the round hole and the battery cell b (3) are completely aligned, it is a complete non-conductivity fault.

[0011] (6) Drive the stepper motor f(69) to rotate clockwise and drive the first gear f(72) to rotate counterclockwise, which in turn drives the second gear f(75) to rotate clockwise. Through the rotation rod c(62), the sector-shaped connecting plate c(60) rotates clockwise along the sector-shaped rotating track (57) to change the relative position relationship between the round hole on the sector-shaped connecting plate c(60) and the battery cell c(4), thus achieving an incomplete conduction fault. When the round hole and the battery cell c(4) are completely aligned, it is a completely non-conducting fault.

[0012] This invention also provides a method for identifying and locating inter-core short circuits and incomplete continuity faults in a three-core cable, comprising:

[0013] (1) Inter-core short circuit fault identification:

[0014]

[0015]

[0016]

[0017] Where y a,i (t), y b,i (t), y c,i (t) represents the reflected signals of the three cells a, b, and c at the fault point i, where T is the mode transformation matrix, and y 0,i (t) is the common-mode signal, y 1,i (t), y 2,i (t) is the differential signal, K i To determine whether a high- or low-resistance inter-core short-circuit fault has occurred at fault point i using the modal coupling factor, and based on the assumption that a short-circuit fault has occurred, R... i Used to determine the short circuit between the ac, ab, and bc cores at the fault location;

[0018] (2) Identification of incomplete cell conduction fault:

[0019]

[0020]

[0021] Where Y d,i For the Fourier transform form of the differential signal, w c The high-frequency boundary angular frequency, w max The maximum angular frequency of the LFM, and the high-frequency energy proportion factor η. i This serves as a way to determine whether a battery cell has experienced an incomplete conduction fault.

[0022] This invention achieves precise location and identification of N mixed fault points along a cable line by injecting linear frequency modulated signals and matching filtering, relying solely on a single end of the cable. It requires no remote synchronization or additional equipment, making it highly adaptable to engineering applications. Utilizing a combined criterion of reflection amplitude, modal coupling factor, and high-frequency energy ratio, it effectively distinguishes between three types of faults: high-resistance short circuits between cells, low-resistance short circuits, and incomplete cell continuity. Furthermore, it can identify the two cells that experienced the short circuit. Simultaneously, LFM pulse compression technology significantly improves the signal-to-noise ratio and time-domain resolution, maintaining stable detection capabilities even over long distances and in environments with strong interference. It is suitable for online or offline maintenance scenarios of various three-core cables in power, rail transit, shipbuilding, and new energy industries, and has significant engineering application value. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the three-core cable inter-core short circuit and incomplete conduction fault simulation device in an embodiment of the present invention.

[0024] Figure 2 This is a diagram of the inter-core high and low resistance short-circuit fault simulation device in an embodiment of the present invention;

[0025] Figure 3 This is a side view of the inter-core high and low resistance short-circuit fault simulation device in an embodiment of the present invention;

[0026] Figure 4 This is a diagram of a device simulating incomplete cell conduction fault in an embodiment of the present invention;

[0027] Figure 5 This is a side view of the cell incomplete conduction fault simulation device in an embodiment of the present invention;

[0028] Figure 6 This is a flowchart of the method for locating and identifying short circuits and incomplete continuity faults between cores of a three-core cable in an embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] like Figures 1-5 As shown, the present invention provides a three-core cable inter-core short circuit and incomplete conduction fault simulation device. In the figure, a mechanical support platform (2) is located at the bottom, and a cable bracket a (6) and a cable bracket b (11) are fixed on it to support the three-core cable (1). Mechanical device brackets a (7), b (8), c (9), and d (10) fixed on it fix the connection between the fault simulation device and the cable through threaded rod b (17) and c (18). The LFM excitation signal generation unit (22) and the echo detection and modulation unit (23) are connected to the cable head end to realize signal injection and acquisition.

[0031] The fault simulation device includes: battery cell a(2), battery cell b(3), and battery cell c(4) which are supported and fixed by a star-shaped battery cell fixing bracket a(12), a battery cell fixing ring a(13), a star-shaped battery cell fixing bracket b(14), and a battery cell fixing ring b(15) fixed by threaded rod a(16), threaded rod b(17), and threaded rod c(18) to facilitate the setting of simulated faults; a motor support platform a(24), a motor support platform b(25), and a motor support platform c(26) are fixed on the battery cell fixing ring a(13), and a stepper motor a(27) is installed on the motor support platform a(24). A first-stage gear a (33) is connected to a second-stage gear a (36) meshing with the first-stage gear a, a claw connecting rod a (39) connected to the first-stage gear a, a claw a (40) connected to the claw connecting rod a, a claw connecting rod b (41) connected to the second-stage gear a, and a claw b (42) connected to the claw connecting rod b; a stepper motor b (28) is mounted on a motor support platform b (25), a first-stage gear b (34) connected to the stepper motor b, a second-stage gear b (37) meshing with the first-stage gear b, a claw connecting rod c (43) connected to the first-stage gear b, and a claw c (44) connected to the claw connecting rod c. The claw connecting rod d (45) is connected to the secondary gear b, and the claw d (46) is connected to the claw connecting rod d; the motor support platform c (26) is equipped with the primary gear c (35) connected to the stepper motor c, the secondary gear c (38) meshing with the primary gear c, the claw connecting rod e (47) connected to the primary gear c, the claw e (48) connected to the claw connecting rod e, the claw connecting rod f (49) connected to the secondary gear c, and the claw f (50) connected to the claw connecting rod f; the battery cell fixing ring a (13) is fixed with the tail end connected to the battery cell a (2), battery cell b (3), and battery cell c (4) respectively. The telescopic conductive rails a (54), b (55), and c (56) are connected. A variable resistor a (51) is fixed on the core fixing ring a (13) between the beginning of the telescopic conductive rail a (54) and the end of the telescopic conductive rail b (55). A variable resistor b (52) is fixed on the core fixing ring a (13) between the beginning of the telescopic conductive rail b (55) and the end of the telescopic conductive rail c (56). A variable resistor c (53) is fixed on the core fixing ring a (13) between the beginning of the telescopic conductive rail c (56) and the end of the telescopic conductive rail a (54).In the fault simulation device, a fan-shaped rotating track (57) is fixed on the main shaft of the star-shaped cell fixing bracket b (14). On both sides of the track, cell brackets a (30) and d (64) are fixed on the cells a (2), b (3), and c (4), respectively. A fan-shaped connecting plate a (58) that fits into the fan-shaped rotating track is sandwiched in between, and a rotating rod a (61) is fixed on it. Cell brackets b (31) and e (65) have a fan-shaped connecting plate b (59) that fits into the fan-shaped rotating track, and a rotating rod b (62) is fixed on it. Cell brackets c (32) and f (66) have a fan-shaped connecting plate c (60) that fits into the fan-shaped rotating track in between. A rotating rod c (63) is fixed on it; a stepper motor d (67) is installed on the cell bracket d (64), and a first-stage gear d (70) is connected to the motor shaft. The second-stage gear d (73) connected to the rotating rod a (61) meshes with the first-stage gear d (70). A stepper motor e (68) is installed on the cell bracket e (65), and a first-stage gear e (71) is connected to the motor shaft. The second-stage gear e (74) connected to the rotating rod b (62) meshes with the first-stage gear e (71). A stepper motor f (69) is installed on the cell bracket f (66), and a first-stage gear f (72) is connected to the motor shaft. The second-stage gear f (75) connected to the rotating rod c (63) meshes with the first-stage gear f (72).

[0032] like Figure 6 As shown, the present invention provides a method for identifying and locating short circuits and incomplete continuity faults between cores of a three-core cable. This method involves injecting linear frequency modulated signals into the ports of the three cores, collecting reflected waves and performing matched filtering, and analyzing the reflection peaks at each fault point in the reflected waves to locate and identify the fault. Specifically, the method includes the following steps:

[0033] Step 1: Simulate short circuits and incomplete continuity faults between the cores of a three-core cable, including:

[0034] 1) One fault simulation device can realize two types of fault simulation. N fault simulation devices are connected in series to realize 2N cable simulation fault settings. Then, the LFM excitation signal generation unit 12 and the echo detection and modulation unit 13 are connected to the input port of the cable.

[0035] 2) Drive the stepper motor a (27) to drive the first gear a (33) to rotate clockwise, and further drive the second gear a (36) to rotate counterclockwise, so that the claw connecting rod a (39) and claw connecting rod b (41) rotate relative to each other, and further drive the claw a (40) and claw b (42) to squeeze the head end of the telescopic conductive rail a (54) and the tail end of the telescopic conductive rail b (55) until they are closed and connected with the variable resistor a (51) to realize the short circuit fault setting between the battery cells a and b. By changing the resistance value of the variable resistor a (51), high and low resistance short circuit faults can be set.

[0036] 3) Similarly, as in operation step 2), high and low resistance short circuit faults between cells ac and BC at N inter-cell short circuit fault points can be resolved.

[0037] 4) Drive the stepper motor d (67) to rotate clockwise and drive the first gear d (70) to rotate counterclockwise, which in turn drives the second gear d (73) to rotate clockwise. Through the rotation rod a (61), the sector-shaped connecting plate a (58) rotates clockwise along the sector-shaped rotating track (57) to change the relative position relationship between the round hole on the sector-shaped connecting plate a (58) and the battery cell a (2), thus achieving an incomplete conduction fault. When the round hole and the battery cell a (2) are completely aligned, it is a completely non-conducting fault.

[0038] 5) Similarly, as in step 4), the incomplete conduction fault setting of cells b and c with N incomplete conduction fault points can be achieved;

[0039] 6) Repeat steps 2) to 5) to simulate the combination of short circuits and incomplete continuity faults at multiple locations of the three-core cable.

[0040] Step Two: Implement methods for identifying and locating inter-core short circuits and incomplete continuity faults in three-core cables, including:

[0041] 1) The LFM signal source is continuously injected into the three-core cable coupling network through power amplification. The echo signal of the coupling network is collected, and after being matched and filtered by the high-speed ADC acquisition unit through the preamplifier unit, it is input to the host computer to realize the processing and analysis of the echo signal.

[0042] 2) The injected linear frequency modulated signal is s(t), and the acquired echo signal is x(t):

[0043]

[0044]

[0045] Where f0 is the starting frequency and T is the pulse width. Let τ be the reflection coefficient at the i-th fault point. i This is the round-trip delay of the signal wave.

[0046] 3) Perform matched filtering on the echo signal:

[0047]

[0048]

[0049] With independent time windows Based on the reference, the signal y is obtained by extracting the i-th fault reflection peak in the reflected wave. i (t).

[0050] 4) Fault location calculation:

[0051]

[0052] Where x i This represents the distance from the fault point to the cable input port, where v is the wave velocity and τ is the wave speed. i The peak time is the time after matched filtering.

[0053] 5) Modal decoupling:

[0054] The matched filter signal y of the three cells at fault point i obtained in step 5) a,i (t), y b,i (t) and y c,i (t), perform mode transformation on it:

[0055]

[0056] Where T is the mode transformation matrix. It is a common-mode signal. , It is a differential signal.

[0057] 6) Construction of features:

[0058]

[0059]

[0060] Where y a,i (t), y b,i (t), y c,i (t) represents the reflected signals of the three cells a, b, and c at the fault point i, where T is the mode transformation matrix, and y 0,i (t) is the common-mode signal, y 1,i (t), y 2,i (t) is the differential signal, K i To determine whether a high- or low-resistance inter-core short-circuit fault has occurred at fault point i using the modal coupling factor, and based on the assumption that a short-circuit fault has occurred, R... i Used to determine the short circuit between the ac, ab, and bc cores at the fault location;

[0061]

[0062]

[0063] Where Y d,i For the Fourier transform form of the differential signal, w c The high-frequency boundary angular frequency, w max The maximum angular frequency of the LFM, and the high-frequency energy proportion factor η.i This serves as a way to determine whether a battery cell has experienced an incomplete conduction fault.

[0064] 7) Criteria for identifying multiple fault types:

[0065] Table 1

[0066] Cable fault types <![CDATA[K i η i Value Incomplete conduction <![CDATA[K i >0.35,h i <0.15]]> High-resistance short circuit between cores <![CDATA[0.15≤η i <0.45]]> Inter-core low-resistance short circuit <![CDATA[η i ≥0.45]]>

[0067] Table 2

[0068] Cable fault types R value AB core short circuit <![CDATA[R ab <0.25]]> AC chip short circuit <![CDATA[R ac <0.25]]> BC chip short circuit <![CDATA[R bc <0.25]]>

Claims

1. A device for simulating short circuits and incomplete continuity faults between cores of a three-core cable, characterized in that: The mechanical device simulates inter-core short circuits and incomplete conduction in a cable, including: a three-core cable (1), core a (2), core b (3), core c (4), a mechanical device support platform (5), a cable bracket a (6) connected to the mechanical support platform, a mechanical device bracket a (7) connected to the support platform, a mechanical device bracket b (8) connected to the support platform, a mechanical device bracket c (9) connected to the support platform, a mechanical device bracket d (10) connected to the support platform, a cable bracket b (11) connected to the support platform, a star-shaped core fixing bracket a (12), a core fixing ring a (13), a star-shaped core fixing bracket b (14), a core fixing ring b (15), a threaded rod a (16), and a threaded rod b (17). Threaded rod c (18), butterfly nut a (19), butterfly nut b (20), butterfly nut c (21), LFM excitation signal generation unit (22), echo detection and modulation unit (23), motor support platform a (24), motor support platform b (25), motor support platform c (26), stepper motor a on motor support platform a (27), stepper motor b on motor support platform b (28), stepper motor c on motor support platform c (29), battery cell bracket a (30), battery cell bracket b (31), battery cell bracket c (32), first-stage gear a connected to stepper motor a (33), first-stage gear b connected to stepper motor b (34), first-stage gear c connected to stepper motor c ( 35) Secondary gear a meshing with primary gear a (36) Secondary gear b meshing with primary gear b (37) Secondary gear c meshing with primary gear c (38) Claw connecting rod a connected to primary gear a (39) Claw a connected to claw connecting rod a (40) Claw connecting rod b connected to secondary gear a (41) Claw b connected to claw connecting rod b (42) Claw connecting rod c connected to primary gear b (43) Claw c connected to claw connecting rod c (44) Claw connecting rod d connected to secondary gear b (45) Claw d connected to claw connecting rod d (46) Claw connecting rod e connected to primary gear c (47) Claw e connected to claw connecting rod e (48) 8) Claw connecting rod f (49) connected to secondary gear c, claw f (50) connected to claw connecting rod f, variable resistor a (51) fixed between battery cells a and b, variable resistor b (52) fixed between battery cells b and c, variable resistor c (53) fixed between battery cells c and a, telescopic conductive rail a (54) connected to battery cell a at the tail end, telescopic conductive rail b (55) connected to battery cell b at the tail end, telescopic conductive rail c (56) connected to battery cell c at the tail end, fan-shaped rotating rail (57) connected to main shaft, fan-shaped connecting disc a (58) fitted with fan-shaped rotating rail, fan-shaped connecting disc b (59) fitted with fan-shaped rotating rail, fan-shaped connecting disc c (60) fitted with fan-shaped rotating rail.Rotating rod a (61) on sector-shaped connecting plate a, rotating rod b (62) on sector-shaped connecting plate b, rotating rod c (63) on sector-shaped connecting plate c, cell bracket d (64), cell bracket e (65), cell bracket f (66), stepper motor d (67) on cell bracket d, stepper motor e (68) on cell bracket e, stepper motor f (69) on cell bracket f, primary gear d (70) connected to stepper motor d, primary gear e (71) connected to stepper motor e, primary gear f (72) connected to stepper motor f, secondary gear d (73) coaxial with rotating rod a and meshing with primary gear d, secondary gear e (74) coaxial with rotating rod b and meshing with primary gear e, secondary gear f (75) coaxial with rotating rod c and meshing with primary gear f.

2. The three-core cable inter-core short circuit and incomplete conduction fault simulation device according to claim 1, characterized in that: The stepper motor a (27) drives the first gear a (33) to rotate clockwise, which in turn drives the second gear a (36) to rotate counterclockwise, thereby causing the claw connecting rod a (39) and claw connecting rod b (41) to rotate relative to each other. This further drives the claw a (40) and claw b (42) to squeeze the head end of the telescopic conductive rail a (54) and the tail end of the telescopic conductive rail b (55) until they are closed and connected with the variable resistor a (51) to realize the short circuit fault setting between the battery cells a and b. By changing the resistance value of the variable resistor a (51), high and low resistance short circuit faults can be set. The stepper motor b (28) drives the first gear b (34) to rotate clockwise, which in turn drives the second gear b (37) to rotate counterclockwise, thereby causing the claw connecting rod c (43) and claw connecting rod d (45) to rotate relative to each other. This further drives the claw c (44) and claw d (46) to squeeze the head end of the telescopic conductive rail b (55) and the tail end of the telescopic conductive rail c (56) until they are closed and connected with the variable resistor b (52) to realize the short circuit fault setting between the battery cells b and c. By changing the resistance value of the variable resistor b (52), high and low resistance short circuit faults can be set. The stepper motor c(29) drives the first gear c(35) to rotate clockwise, which in turn drives the second gear c(38) to rotate counterclockwise, thereby causing the claw connecting rod e(47) and claw connecting rod f(49) to rotate relative to each other. This further drives the claw e(48) and claw f(50) to squeeze the head end of the telescopic conductive rail c(56) and the tail end of the telescopic conductive rail a(54) until they are closed and connected with the variable resistor c(53) to realize the short circuit fault setting between the battery cell a and c. By changing the resistance value of the variable resistor c(53), high and low resistance short circuit faults can be set. The stepper motor d (67) drives the first gear d (70) to rotate clockwise and then rotate counterclockwise, which in turn drives the second gear d (73) to rotate clockwise. Through the rotation rod a (61), the fan-shaped connecting plate a (58) rotates clockwise along the fan-shaped rotating track (57) to change the relative position relationship between the round hole on the fan-shaped connecting plate a (58) and the battery cell a (2), thus achieving an incomplete conduction fault. When the round hole and the battery cell a (2) are completely aligned, it is a completely non-conducting fault. The stepper motor e (68) drives the first gear e (71) to rotate clockwise and then rotate counterclockwise, which in turn drives the second gear e (74) to rotate clockwise. Through the rotation rod b (61), the fan-shaped connecting plate b (59) rotates clockwise along the fan-shaped rotating track (57) to change the relative position relationship between the round hole on the fan-shaped connecting plate b (59) and the battery cell b (3), thus achieving an incomplete conduction fault. When the round hole and the battery cell b (3) are completely aligned, it is a completely non-conducting fault. The stepper motor f(69) drives the first gear f(72) to rotate clockwise and then rotate counterclockwise, which in turn drives the second gear f(75) to rotate clockwise. Through the rotation rod c(62), the sector-shaped connecting plate c(60) rotates clockwise along the sector-shaped rotating track (57) to change the relative position relationship between the circular hole on the sector-shaped connecting plate c(60) and the battery cell c(4), thus achieving an incomplete conduction fault. When the circular hole and the battery cell c(4) are completely aligned, it is a completely non-conducting fault.

3. A method for identifying and locating inter-core short circuits and incomplete continuity faults in a three-core cable, characterized in that, include: (1) Inter-core short circuit fault identification: Where y a,i (t), y b,i (t), y c,i (t) represents the reflected signals of the three cells a, b, and c at the fault point i, where T is the mode transformation matrix, and y 0,i (t) is the common-mode signal, y 1,i (t), y 2,i (t) is the differential signal, K i To determine whether a high- or low-resistance inter-core short-circuit fault has occurred at fault point i using the modal coupling factor, and based on the assumption that a short-circuit fault has occurred, R... i Used to determine the short circuit between the ac, ab, and bc cores at the fault location; (2) Identification of incomplete cell conduction fault: Where Y d,i For the Fourier transform form of the differential signal, w c The high-frequency boundary angular frequency, w max The maximum angular frequency of the LFM, and the high-frequency energy proportion factor η. i This serves as a way to determine whether a battery cell has experienced an incomplete conduction fault.

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