A method, device, system and train for power failure location

Abstract

The application discloses a power supply fault positioning method, device, system and train, and relates to the field of fault positioning, and comprises the following steps: acquiring line parameters of a traction power supply network and establishing an electrical parameter model, so that the fault positioning process can be based on the actual power supply line structure, and the matching degree of the model and the actual traction power supply network is improved; inputting a fault positioning pulse wave to the traction power supply network and acquiring propagation data, so that the detection of the fault propagation process is realized; analyzing the reflection wave data generated in the propagation process, determining the fault reflection wave, and reducing the influence of line structure changes on the fault detection result; determining the fault type according to the fault reflection wave and determining the fault position according to the fault reflection wave propagation time delay, so that the rapid positioning of the traction power supply network fault point is realized. Therefore, the application can reduce the artificial investigation workload, improve the fault positioning efficiency and positioning accuracy, shorten the fault maintenance time, and improve the operation reliability of the high-speed maglev traction power supply system.

Description

Technical Field

[0001] This invention relates to the field of fault location, and in particular to a method, apparatus, system, and train for locating power supply faults. Background Technology

[0002] The high-speed maglev traction power supply system adopts a segmented power supply method with a long stator. It consists of traction substations, feeder cables, stator switching stations, and winding cables, forming a traction power supply network to provide the traction power required for the high-speed maglev train's operation. Because the traction power supply network covers a long distance along the line and includes different types of cables, joints, and connection structures, it is susceptible to environmental factors, electrical stress, and mechanical losses during long-term operation, leading to a decline in line insulation performance and subsequent problems such as grounding faults, short-circuit faults, and open-circuit faults. When a fault occurs in the traction power supply network, it is necessary to promptly determine the fault location for repair. Currently, manual inspection or fault detection equipment is commonly used for troubleshooting. However, due to the long length of high-speed maglev lines and the complex distribution of power supply equipment, manual methods suffer from problems such as a large detection range, difficulty in quickly identifying fault points, and low location efficiency. Existing traveling wave fault location methods determine the fault location by detecting the reflected waves generated by the fault. However, they do not fully consider the changes in wave impedance caused by different cable structures, cable joints, and busbars in the high-speed maglev traction power supply network. This makes it easy for a large number of structural reflection waves to be generated during the propagation of the traveling wave, making it difficult to distinguish between the fault reflection wave and the structural reflection wave, thus affecting the accuracy of the fault location calculation. Summary of the Invention

[0003] The purpose of this invention is to provide a method, device, system, and train for locating power supply faults, which can reduce the workload of manual troubleshooting, improve the efficiency and accuracy of fault location, shorten the fault repair time, and improve the operational reliability of the high-speed maglev traction power supply system.

[0004] To solve the above-mentioned technical problems, the present invention provides a method for locating power supply faults. The traction power supply network includes feeder cables, stator winding cables, cable joints, and busbars. The method for locating power supply faults includes: Determine the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and the stator section winding cable; Obtain the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and the busbar. A π-type equivalent circuit is established based on the cable equivalent inductance, the cable equivalent capacitance, the cable insulation resistance parameters, the interface equivalent inductance, the interface equivalent capacitance, and the interface equivalent resistance parameters; The electrical parameter model is established based on the π-type equivalent circuit. Input a fault location pulse wave into the traction power supply network and obtain the propagation data of the fault location pulse wave in the electrical parameter model; The reflected wave data is determined based on the propagation data, and the fault reflected wave is determined based on the reflected wave data; The fault type is determined based on the fault reflection wave; The propagation delay of the fault reflected wave is determined based on the fault reflected wave, and the fault location is determined based on the propagation delay.

[0005] On the other hand, determining the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and the stator section winding cable includes: Based on the structural parameters of the feeder cable and the stator section winding cable, the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the cable are determined. The expression for the equivalent inductance per unit length of the cable is: ; in, The equivalent inductance per unit length of cable, The permeability of free space, Relative permeability; The expression for the equivalent capacitance per unit length of cable is: ; in, Here, R is the equivalent capacitance per unit length of cable, R is the radius of the grounding aluminum foil, and r is the radius of the cable core. The vacuum permittivity, It is the relative permittivity; The expression for the insulation resistance of the cable is: ; in, The insulation resistance per unit length of cable. The unit insulation resistance value at 20℃ This is the temperature coefficient.

[0006] On the other hand, obtaining the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and the busbar includes: Determine the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the interface based on the structural parameters of the cable joint and busbar. The formula for calculating the equivalent inductance of the interface is as follows: ; The formula for calculating the equivalent capacitance of the interface is as follows: ; The formula for calculating the equivalent resistance of the interface is: ; in, The equivalent inductance per unit length of the interface, This is the inductance correction factor. Based on the basic inductance parameters, The equivalent capacitance per unit length of the interface. This is the capacitance correction factor. Based on the basic capacitance parameters, The equivalent resistance per unit length of the interface. This is the resistance correction factor. These are the basic resistance parameters.

[0007] On the other hand, a fault location pulse wave is input to the traction power supply network, and the propagation data of the fault location pulse wave in the electrical parameter model is obtained, including: The standard fault location pulse wave is determined as the incident wave; Based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations of the line structure are obtained. The reflected wave characteristics corresponding to different line structure positions are determined based on the reflected wave and the refracted wave. The reflected wave characteristics include the reflected wave amplitude, the polarity of the reflected wave, the reflected wave time delay, and the waveform changes of the reflected wave.

[0008] On the other hand, based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations in the line structure are obtained, including: Based on the change in wave impedance when the incident wave passes through the connection position between lines with different wave impedances, determine the voltage of the reflected wave and the voltage of the refracted wave corresponding to the incident wave. The expression for the voltage of the refracted wave is: ; The expression for the voltage of the reflected wave is: ; The wave impedance of the first line is The wave impedance of the second line is The voltage of the incident wave is The voltage of the reflected wave is The voltage of the refracted wave is The voltage refractive index is The voltage reflection coefficient is .

[0009] On the other hand, determining reflected wave data based on the propagation data, and determining fault reflected waves based on the reflected wave data, includes: Based on the line parameters corresponding to the cable joints and busbars in the electrical parameter model, determine the reflected voltage corresponding to the joint reflected wave; The dynamic compensation parameters are determined based on the reflected voltage. The identified joint reflection wave is compensated according to the dynamic compensation parameters to eliminate the influence of the joint reflection wave on the fault reflection wave; The fault reflection wave is determined based on the compensated reflection wave data.

[0010] On the other hand, determining the fault type based on the fault reflection wave includes: The reflected wave data is matched according to the fault reflected wave characteristics corresponding to the preset fault type; The fault type corresponding to the fault reflection wave is determined based on the matching results; The fault reflection wave characteristics include fault type, fault location, reflection wave amplitude, reflection wave polarity, reflection wave time delay, and waveform distortion characteristics.

[0011] On the other hand, determining the fault type corresponding to the fault reflection wave based on the matching results includes: When the polarity of the reflected wave is opposite to that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be a short-circuit fault. When the polarity of the reflected wave is the same as that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be an open circuit fault.

[0012] On the other hand, determining the fault type corresponding to the fault reflection wave based on the matching results includes: When the amplitude of the reflected wave is close to the amplitude of the incident wave, and the waveform of the reflected wave shows obvious abrupt change characteristics, the fault type is determined to be a low-resistance short-circuit fault. When the amplitude of the reflected wave is lower than the amplitude corresponding to a low-resistance short-circuit fault, and the waveform of the reflected wave exhibits a wide amplitude variation, the fault type is determined to be a medium-resistance short-circuit fault. When the amplitude of the reflected wave further decreases and the waveform of the reflected wave exhibits a slow change characteristic, the fault type is determined to be a high-resistance grounding fault. When the amplitude of the reflected wave is close to the amplitude of the incident wave, and the polarity of the reflected wave is consistent with the polarity of the incident wave, the fault type is determined to be an open circuit fault.

[0013] On the other hand, determining the propagation delay of the fault reflected wave based on the fault reflected wave, and determining the fault location based on the propagation delay, includes: When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector. When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector. When the propagation delay of the fault reflected wave is greater than the reference propagation delay corresponding to the last connector, the fault location is determined to be in the area of ​​the end power supply line.

[0014] On the other hand, when the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, determining that the fault location is in the power supply line area before the first connector includes: The fault location is determined based on the propagation delay of the fault reflected wave and the calibrated wave velocity. The expression for the fault location is: ; When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector, including: The fault location is determined based on the propagation delay of the k-th connector and the position of the k-th connector. The expression for the fault location is: ; in, The fault location is V, the calibrated wave velocity is V, and the propagation delay of the fault reflected wave is t. Let the reference propagation delay be the k-th connector. Let k be the position of the k-th connector, where k is a positive integer greater than 1.

[0015] To solve the above-mentioned technical problems, the present invention also provides a power supply fault location device, comprising: Memory, used to store computer programs; A processor is used to implement the steps of the above-described method for locating power supply faults when executing the computer program.

[0016] On the other hand, it also includes: An input interface, connected to the processor, is used to acquire externally imported computer programs, parameters, and commands, and save them to the memory under the control of the processor. The display unit, connected to the processor, is used to display the data sent by the processor; The network port is connected to the processor and is used for communication with external terminal devices.

[0017] To address the aforementioned technical problems, the present invention also provides a power supply fault location system, comprising the aforementioned power supply fault location device, and further comprising: A pulse signal generating module is connected to the power supply fault location device and is used to input fault location pulse waves to the traction power supply network; The data acquisition module is connected to the power supply fault location device and is used to collect reflected wave data in the traction power supply network.

[0018] On the other hand, it also includes: The waveform display module is connected to the power supply fault location device and is used to display the waveform of the original reflected wave, the waveform of the processed reflected wave, and the fault location marker.

[0019] To solve the above-mentioned technical problems, the present invention also provides a train, including the above-mentioned power supply fault location system, and further comprising: The traction power supply network, connected to the power supply fault location system, is used to provide traction power to the train.

[0020] On the other hand, the traction power supply network includes traction substations, feeder cables, stator switch stations, feeder cables, and stator section winding cables; The traction substation is connected to the feeder cable and is used to output traction power. The feeder cable is connected to the stator switch station and is used to transmit the traction power supply. The stator switch station is connected to the feeder cable and is used to control the transmission of traction power to different stator sections; The feeder cable is connected to the stator winding cable and is used to provide traction power to the stator winding corresponding to the train.

[0021] This application provides a method, apparatus, system, and train for power supply fault location, relating to the field of fault location. The method includes acquiring line parameters of the traction power supply network and establishing an electrical parameter model, enabling the fault location process to be based on the actual power supply line structure and improving the matching degree between the model and the actual traction power supply network; inputting a fault location pulse wave into the traction power supply network and acquiring propagation data to detect the fault propagation process; analyzing the reflected wave data generated during propagation to determine the fault reflected wave, reducing the impact of line structure changes on fault detection results; determining the fault type based on the fault reflected wave and determining the fault location based on the propagation delay of the fault reflected wave, achieving rapid location of the fault point in the traction power supply network. Therefore, this application can reduce the workload of manual troubleshooting, improve fault location efficiency and accuracy, shorten fault repair time, and improve the operational reliability of the high-speed maglev traction power supply system. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart of a power supply fault location method provided by the present invention; Figure 2 This is a schematic diagram of the structure of a π-type equivalent circuit provided by the present invention; Figure 3 A schematic diagram of a traveling wave reflection structure provided by the present invention; Figure 4 A schematic diagram of a fault-free waveform provided by the present invention; Figure 5 This invention provides a structural schematic diagram of an open-circuit fault waveform for an intermediate connector. Figure 6 A schematic diagram of a short-circuit fault waveform before an intermediate connector provided by the present invention; Figure 7 A schematic diagram of a short-circuit fault waveform after an intermediate connector provided by the present invention; Figure 8 A schematic diagram of the structure of a power supply fault location device provided by the present invention; Figure 9 A schematic diagram of a power supply fault location system provided by the present invention; Figure 10 This is a schematic diagram of a traction power supply network provided by the present invention. Detailed Implementation

[0024] The core of this invention is to provide a method, device, system, and train for locating power supply faults, which can reduce the workload of manual troubleshooting, improve the efficiency and accuracy of fault location, shorten the fault repair time, and improve the operational reliability of the high-speed maglev traction power supply system.

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Figure 1A flowchart of a power supply fault location method provided by the present invention is shown. The traction power supply network includes feeder cables, stator winding cables, cable joints, and busbars. The power supply fault location method includes: The high-speed maglev traction power supply system adopts a segmented power supply method with a long stator. The traction power supply network can include traction substations, feeder cables, stator switching stations, feeder cables, and stator segment winding cables. The traction substation converts the input electrical energy into traction-suitable power and transmits it to the stator switching station via feeder cables. The stator switching station switches the power supply path according to the stator segment where the train is running, so that the traction power supply is transmitted via feeder cables to the corresponding stator segment winding cables, which then supply power to the stator windings. Symmetrical three-phase currents are formed in the stator windings, creating a traveling wave magnetic field propagating along the track direction. This traveling wave magnetic field interacts with the constant magnetic field on the train to generate traction force, enabling train acceleration and operation. Because the feeder cables and stator segment winding cables are arranged in segments along the track, and there are cable joints and busbars for connection, the traction power supply network is not an ideally uniform line.

[0027] This embodiment first obtains the line parameters of the traction power supply network and establishes an electrical parameter model based on these parameters. The line parameters describe the electrical characteristics of different line sections and connection structures within the traction power supply network, and may include resistance, inductance, capacitance, and insulation characteristics related to voltage and current propagation. By obtaining the line parameters of the actual traction power supply network, the subsequent fault location process can use electrical parameters corresponding to the actual power supply lines, rather than simply treating the entire traction power supply network as a uniform line with consistent parameters. Therefore, when the fault location pulse wave propagates between different line sections, the propagation changes caused by different line structures can be reflected in the electrical parameter model.

[0028] S11: Determine the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and stator section winding cable; Figure 2 This is a schematic diagram of the structure of a π-type equivalent circuit provided by the present invention; like Figure 2 As shown, this embodiment uses a π-type equivalent circuit to describe the line parameters in the traction power supply network. Wherein, The equivalent inductance per unit length of cable, The equivalent capacitance per unit length of cable. This represents the insulation resistance per unit length of the cable. Since fault location pulse waves are rapidly changing voltage waves, they can complete voltage changes over a large area within a short time. For example, when the wavefront time is the first time parameter, the distribution distance of the impulse voltage wavefront on the line may only be a few hundred meters. Therefore, a lumped parameter model cannot simply assume that the voltage and current at both ends of the line are instantaneously the same. A distributed parameter model can consider the influence of factors such as conductor length and cross-section on voltage and current distribution, and utilize traveling wave theory to describe the propagation, reflection, refraction, and superposition processes of voltage and current waves in the power supply line.

[0029] This embodiment first determines the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and stator winding cable. The equivalent inductance describes the electromagnetic energy storage characteristics generated by the conductor and its surrounding magnetic field during the propagation of the fault location pulse wave; the equivalent capacitance describes the electric field energy storage characteristics between the cable core and the grounding structure; and the insulation resistance describes the limiting effect of the cable insulation structure on leakage current. By processing these parameters according to the unit length of the line, feeder cables and stator winding cables of different lengths can be represented using a corresponding number of π-type equivalent units.

[0030] S12: Obtain the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and busbar. Furthermore, the equivalent inductance, capacitance, and resistance parameters of the cable joints and busbars are obtained. Compared to continuous cable sections, cable joints and busbars have changes in connection structure and geometry, resulting in differences in their equivalent inductance, capacitance, and resistance. Therefore, they are described as independent line structures in the model. This way, when a fault location pulse wave propagates to the cable joint or busbar, the electrical parameter model can generate a surge impedance change corresponding to the actual line parameter changes.

[0031] S13: Establish a π-type equivalent circuit based on the parameters of cable equivalent inductance, cable equivalent capacitance, cable insulation resistance, interface equivalent inductance, interface equivalent capacitance, and interface equivalent resistance. S14: Establish an electrical parameter model based on the π-type equivalent circuit; Subsequently, a π-type equivalent circuit is established based on the cable's equivalent inductance, equivalent capacitance, insulation resistance, interface equivalent inductance, equivalent capacitance, and equivalent resistance parameters. An electrical parameter model is then built based on this π-type equivalent circuit. Each unit length of cable segment can be represented by a single π-type equivalent unit, or multiple consecutive π-type equivalent units can be set according to the required model accuracy. Cable joints and busbars are described using the corresponding interface parameters.

[0032] This method allows the electrical differences between continuous cable sections and discontinuous connection locations to be reflected simultaneously in the electrical parameter model, making the propagation process of the fault location pulse wave in the model closer to the actual traction power supply network, thus providing a basis for subsequent reflected wave identification and fault location calculation.

[0033] S15: Input a fault location pulse wave into the traction power supply network and obtain the propagation data of the fault location pulse wave in the electrical parameter model; Furthermore, a fault location pulse wave is input into the traction power supply network, and its propagation data in the electrical parameter model is acquired. The fault location pulse wave can be a pulse signal with a short rise time, which propagates along the power supply line after being input into the traction power supply network. Due to cable joints, busbars, and other locations where line parameters change, the fault location pulse wave will undergo reflection, refraction, and superposition when it propagates to these locations. The propagation data is used to record the propagation state of the fault location pulse wave in the electrical parameter model, enabling the subsequent acquisition of reflected wave information from the propagation process.

[0034] S16: Determine the reflected wave data based on the propagation data, and determine the fault reflected wave based on the reflected wave data; Furthermore, reflected wave data is determined based on the propagation data, and fault reflected waves are identified based on the reflected wave data. Specifically, the voltage waveform in the propagation data can be detected, and reflected wave data can be extracted based on the correspondence between the incident wave and the returned wave on the time axis. Since normal cable joints and busbars also generate reflected waves, not all reflected waves indicate a line fault. It is necessary to distinguish them based on characteristics such as the time of occurrence, amplitude, polarity, and waveform changes of the reflected waves to determine the fault reflected wave corresponding to the fault location.

[0035] S17: Determine the fault type based on the fault reflection wave; There may be a variety of causes for a fault, which can be classified as short circuit or open circuit fault. Short circuit faults can be further divided into various configuration types. The specific type of fault can be determined based on the fault reflection wave, which facilitates subsequent maintenance personnel to handle the fault type accordingly.

[0036] S18: Determine the propagation delay of the fault reflected wave based on the fault reflected wave, and determine the fault location based on the propagation delay.

[0037] Furthermore, the propagation delay of the fault reflected wave is determined based on the reflected wave, and the fault location is determined based on the propagation delay. Specifically, the time it takes for the fault location pulse wave to propagate from the input position to the fault point and then return to the detection position can be determined, and this time is used as the propagation delay of the fault reflected wave. Since there is a corresponding relationship between propagation distance and propagation delay, the location of the fault point can be determined based on the propagation delay. For traction power supply networks containing multiple cable joints, the line section where the fault is located can also be determined based on the propagation time relationship between the reflected wave and each joint.

[0038] Through the above process, the corresponding electrical parameter model can be established using the line parameters of the traction power supply network itself, and the fault location can be determined by using the propagation and reflection information of the fault location pulse wave in the model. This reduces the workload of manually checking fault points segment by segment and reduces the impact of line structure changes on the fault location process.

[0039] This application provides a method, apparatus, system, and train for power supply fault location, relating to the field of fault location. The method includes acquiring line parameters of the traction power supply network and establishing an electrical parameter model, enabling the fault location process to be based on the actual power supply line structure and improving the matching degree between the model and the actual traction power supply network; inputting a fault location pulse wave into the traction power supply network and acquiring propagation data to detect the fault propagation process; analyzing the reflected wave data generated during propagation to determine the fault reflected wave, reducing the impact of line structure changes on fault detection results; determining the fault type based on the fault reflected wave and determining the fault location based on the propagation delay of the fault reflected wave, achieving rapid location of the fault point in the traction power supply network. Therefore, this application can reduce the workload of manual troubleshooting, improve fault location efficiency and accuracy, shorten fault repair time, and improve the operational reliability of the high-speed maglev traction power supply system.

[0040] Based on the above embodiments: In some embodiments, determining the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and stator section winding cable includes: The equivalent inductance, equivalent capacitance, and insulation resistance of the cable are determined based on the structural parameters of the feeder cable and stator winding cable. The expression for the equivalent inductance per unit length of cable is as follows: ; in, R is the equivalent inductance per unit length of cable, R is the radius of the grounding aluminum foil, and r is the radius of the cable core. The permeability of free space, Relative permeability; The expression for the equivalent capacitance per unit length of cable is: ; in, The equivalent capacitance per unit length of cable. The vacuum permittivity, It is the relative permittivity; The expression for cable insulation resistance is: ; in, The insulation resistance per unit length of cable. The unit insulation resistance value at 20℃ This is the temperature coefficient.

[0041] First, the equivalent inductance per unit length of the cable is determined based on the structural parameters of the feeder cable and the stator winding cable. Its expression is: .

[0042] In the calculation, R and r are obtained based on the actual cable structure, and μr is determined based on the magnetic properties of the conductor and the surrounding medium. Substituting these parameters into the expression yields the equivalent inductance per unit length of cable. This parameter describes the magnetic field energy stored per unit length of cable due to current changes and its impact on pulse wave propagation.

[0043] Secondly, the equivalent capacitance per unit length of cable is determined based on the structural parameters of the feeder cable and the stator winding cable, and its expression is as follows: .

[0044] This expression allows us to obtain the capacitance parameter per unit length based on the geometric relationship between the cable core and the grounding aluminum foil, as well as the dielectric properties of the medium. This parameter describes the electric field energy storage characteristics between the cable core and the grounding structure during the propagation of the fault location pulse wave, and together with the equivalent inductance of the cable, it affects the propagation speed and waveform of the pulse wave.

[0045] Furthermore, the cable insulation resistance is determined based on the cable insulation characteristics, and its expression is as follows: Since cable insulation performance is affected by ambient temperature, using a temperature coefficient to correct the unit insulation resistance value under a 20℃ baseline condition can make the insulation resistance parameters in the model correspond to actual environmental conditions.

[0046] In obtaining , and Then, the above parameters are configured into the corresponding π-type equivalent circuits of the feeder cable and stator winding cable, respectively. This allows the cable structure dimensions, dielectric parameters, and temperature factors to be incorporated into the electrical parameter model, enabling the model to more accurately describe the propagation state of the fault location pulse wave in the feeder cable and stator winding cable, and providing a parameter basis for subsequent calculations of wave impedance and reflection characteristics.

[0047] In some embodiments, obtaining the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and busbar interfaces includes: Determine the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the interface based on the structural parameters of the cable joint and busbar. The formula for calculating the equivalent inductance of the interface is as follows: ; The formula for calculating the equivalent capacitance of the interface is: ; The formula for calculating the equivalent resistance of the interface is: ; in, The equivalent inductance per unit length of the interface, This is the inductance correction factor. Based on the basic inductance parameters, The equivalent capacitance per unit length of the interface. This is the capacitance correction factor. Based on the basic capacitance parameters, The equivalent resistance per unit length of the interface. This is the resistance correction factor. These are the basic resistance parameters.

[0048] Cable joints and busbars are line connection points in the traction power supply network, and their structures differ from those of continuous cable sections. When a fault location pulse wave propagates to these connection points, the equivalent electrical parameters of the line change, resulting in a discontinuity in wave impedance. Therefore, in this embodiment, cable joints and busbars are parameterized as interface structures.

[0049] First, the equivalent inductance, equivalent capacitance, and equivalent resistance of the interface are determined based on the structural parameters of the cable connector and busbar. The equivalent inductance is corrected using the base inductance parameters and an inductance correction factor. This correction factor reflects the changes in electromagnetic energy storage characteristics of the actual interface structure relative to the base structure. This correction method reflects the structural differences between the cable connector and busbar in the equivalent inductance of the interface.

[0050] The equivalent capacitance of the interface is corrected using the base capacitance parameters and a capacitance correction factor. By correcting the base capacitance parameters using KC, the capacitance variations caused by factors such as interface structure dimensions, connection method, and dielectric distribution can be reflected.

[0051] The equivalent resistance of the interface is corrected using the base resistance parameters and a resistance correction factor. By correcting the base resistance parameters with the resistance correction factor, the influence of the interface connection status on the line resistance can be incorporated into the model.

[0052] In some implementations, parameter records can be established for different specifications of cable connectors and busbars, and the corresponding parameters can be called according to the actual installation location. , and Then the calculated , and The circuit is configured in the π-type equivalent circuit of the corresponding interface. When the fault location pulse wave passes through the interface, the model can calculate the corresponding propagation change based on the interface parameters. Therefore, in subsequent reflected wave processing, it is possible to distinguish between joint reflected waves formed by normal connection structures and fault reflected waves formed by faults.

[0053] In some embodiments, a fault location pulse wave is input to the traction power supply network, and the propagation data of the fault location pulse wave in the electrical parameter model is obtained, including: The standard fault location pulse wave is determined as the incident wave; Based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations of the line structure are obtained. The characteristics of reflected waves at different line structure locations are determined based on reflected and refracted waves. These characteristics include reflected wave amplitude, polarity, time delay, and waveform changes.

[0054] In this embodiment, a standard fault location pulse wave is selected as the incident wave. The standard fault location pulse wave is used to provide a uniform detection excitation to the traction power supply network, making the reflected wave data obtained from different detection times and different line sections comparable.

[0055] In one specific implementation, the standard fault location pulse wave is generated using a pulse signal generator. The wavefront time of the standard fault location pulse wave uses a first time parameter, specifically 1.2 μs; the half-peak time uses a second time parameter, specifically 50 μs; the pulse amplitude is set to 10%-20% of the rated voltage of the traction power supply system; and the repetition frequency is set to 1 Hz. During one fault location process, three standard fault location pulse waves are continuously input, and the average value of the reflected wave data obtained from the three detections is taken.

[0056] Using standardized incident waveforms provides a unified reference basis for the polarity, amplitude, time delay, and waveform distortion of fault reflected waves. For example, if input pulses with significant differences in amplitude and waveform are used at different detection times, the amplitude variation of the reflected wave may be simultaneously affected by the input wave variation, increasing the difficulty of fault feature identification. By adopting a unified standard fault location pulse wave, variations in reflected waves can be primarily attributed to changes in the line structure or fault state of the traction power supply network.

[0057] After the standard fault location pulse wave is input into the electrical parameter model, it propagates along each line segment. During propagation, the fault location pulse wave is reflected and refracted upon encountering cable joints, busbars, and other locations where line parameters change. The propagation data thus contains waveform change information from multiple line structural locations. By continuously inputting the pulse wave multiple times and averaging the results, the impact of random interference in a single acquisition on the reflected wave identification results can be reduced, making subsequent reflected wave analysis more stable.

[0058] Figure 3 A schematic diagram of a traveling wave reflection structure provided by the present invention; In some embodiments, based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations in the line structure are obtained, including: Based on the change in wave impedance when the incident wave passes through the connection position between lines with different wave impedances, determine the voltage of the reflected wave and the voltage of the refracted wave corresponding to the incident wave. The expression for the voltage of a refracted wave is: ; The expression for the voltage of the reflected wave is: ; The wave impedance of the first line is The wave impedance of the second line is The voltage of the incident wave is The voltage of the reflected wave is The voltage of the refracted wave is The voltage refractive index is The voltage reflection coefficient is .

[0059] like Figure 3 As shown, when the incident wave propagates from the first line to the second line, point A is the junction of the first and second lines. If the first and second lines have different wave impedances, the incident wave will not enter the second line completely after reaching the junction of the two lines. Instead, some energy will be reflected and the remaining energy will be refracted. Figure 3 In the middle, the wave impedance of the first line is The wave impedance of the second line is The voltage of the incident wave is The voltage of the reflected wave is The voltage of the refracted wave is The voltage refractive index is The voltage reflection coefficient is .

[0060] This embodiment determines the voltage of the reflected wave and the voltage of the refracted wave based on the change in wave impedance when the incident wave passes through the connection points between lines with different wave impedances. The formula for calculating the voltage of the refracted wave is: .

[0061] From the above formula, it can be seen that the voltage of the refracted wave is related to the wave impedance of the second line and the voltage of the incident wave. When and When the voltage of the refracted wave changes, the voltage of the refracted wave also changes.

[0062] The formula for calculating the voltage of the reflected wave is: .

[0063] It is used to represent the proportional relationship between the voltage of the reflected wave and the voltage of the incident wave, and also reflects the influence of changes in wave impedance at the line connection location on the reflected wave. When Greater than hour, When the polarity is positive, the polarity of the reflected wave is the same as that of the incident wave; when Less than hour, The polarity of the reflected wave is negative, and the polarity is opposite to that of the incident wave. When the impedances of the two lines are close, the voltage of the reflected wave is relatively small.

[0064] Therefore, by analyzing the wave impedance corresponding to each location of the line structure in the electrical parameter model, and using the aforementioned calculation relationships of refracted and reflected waves, the characteristics of reflected waves corresponding to different line structure locations can be obtained. These reflected wave characteristics can include the amplitude, polarity, time delay, and waveform variation of the reflected wave. The aforementioned calculation relationships of reflection and refraction are used to describe the propagation law of traveling waves in the traction power supply network and provide a calculation basis for identifying joint reflected waves.

[0065] In some embodiments, determining reflected wave data based on propagation data and determining fault reflected waves based on reflected wave data includes: Based on the line parameters corresponding to the cable joints and busbars in the electrical parameter model, determine the reflected voltage corresponding to the reflected wave of the joint; The dynamic compensation parameters are determined based on the reflected voltage. The identified joint reflection wave is compensated according to the dynamic compensation parameters to eliminate the influence of the joint reflection wave on the fault reflection wave; The fault reflection wave is determined based on the compensated reflection wave data.

[0066] After obtaining the propagation data, the reflected voltage corresponding to the reflected wave at the cable joint is determined based on the line parameters corresponding to the cable joint and busbar in the electrical parameter model. Specifically, the wave impedance at the corresponding location is determined based on the equivalent inductance, equivalent capacitance, and equivalent resistance of each cable joint and busbar interface, and the theoretical reflected voltage generated at that location is calculated by combining the voltage state when the incident wave propagates to that location.

[0067] Because normal cable joints and busbars generate inherent reflections, the detected reflected wave data usually contains both joint reflected waves and reflected waves that may be generated by faults. For each known structural location, a corresponding joint reflected wave reference characteristic can be established based on its line parameters and the propagation time delay at its location.

[0068] Furthermore, dynamic compensation parameters are determined based on the reflected voltage. These parameters represent the degree of influence of the reflected wave from the joint corresponding to the current line structure on the acquired reflected wave data. The dynamic compensation parameters can be determined based on the amplitude difference, polarity relationship, and propagation time relationship between the theoretical reflected voltage and the actual acquired reflected wave.

[0069] Subsequently, the identified joint reflection waves are compensated according to dynamic compensation parameters to eliminate the influence of joint reflection waves on fault reflection waves. For example, for the inherent reflection wave generated at the first joint, the compensation amount can be determined based on the theoretical reflection voltage of that joint, and the reflection component corresponding to that joint can be subtracted or canceled from the reflection wave data to obtain the compensated reflection wave data. For multiple joints, the corresponding joint reflection waves can be identified and compensated sequentially according to their propagation order.

[0070] After compensation is completed, the fault reflected wave is determined based on the compensated reflected wave data. Since the joint reflected wave has been compensated according to the actual line parameters, the abnormal amplitude, polarity, and waveform changes related to the fault in the remaining reflected wave are more obvious, thereby reducing the interference caused by the normal joint reflected wave to the identification of the fault reflected wave.

[0071] In some embodiments, determining the fault type based on the fault reflection wave includes: Match the reflected wave data according to the fault reflection wave characteristics corresponding to the preset fault type; Determine the fault type corresponding to the fault reflection wave based on the matching results; Among them, the characteristics of fault reflection waves include fault type, fault location, reflected wave amplitude, reflected wave polarity, reflected wave time delay, and waveform distortion characteristics.

[0072] A pre-established correspondence between fault reflection wave characteristics and fault types is established. Fault reflection wave characteristics include at least the fault type, fault location, reflected wave amplitude, reflected wave polarity, reflected wave time delay, and waveform distortion characteristics. During actual detection, the amplitude, polarity, time delay, and waveform characteristics of each reflected wave are extracted from the compensated reflected wave data and matched with the characteristics corresponding to the pre-defined fault types.

[0073] like Figure 4 As shown, under fault-free operating conditions, the traction power supply network mainly contains inherent reflected waves generated by joints at various levels, at t 01 The reflected wave from the first connector is generated at t 02 The second joint generates a reflected wave, but there is no obvious fault reflection component. At this point, the amplitude of the joint reflected wave can be approximately 15%-20% of the incident wave amplitude. The polarity of the reflected wave is consistent with the incident wave, the waveform is relatively smooth and without significant distortion, and its propagation delay corresponds to the round-trip propagation delay of the corresponding joint. Therefore, if the acquired reflected wave meets the above characteristics, it can be identified as an inherent reflection corresponding to the line structure, rather than a fault reflection wave.

[0074] In cases where a fault exists, it can be identified based on the changes in the reflected wave relative to the fault-free state. For example, if the amplitude of a reflected wave deviates significantly from the inherent reflected wave amplitude of the corresponding joint, and there is also a significant change in polarity or waveform distortion, it can be considered a candidate fault reflected wave.

[0075] By establishing preset fault reflection wave characteristics, fault judgment can be avoided by relying solely on a single amplitude parameter, instead taking into account amplitude, polarity, time delay, and waveform distortion. When different fault types produce reflected waves with similar amplitudes, polarity and waveform characteristics can be further used for differentiation; when similar waveforms are generated at different locations, propagation time delay can be used for differentiation. This improves the reliability of fault reflection wave screening and provides a unified characteristic basis for subsequent fault type judgment and fault location determination.

[0076] In some embodiments, determining the fault type corresponding to the fault reflection wave based on the matching result includes: When the polarity of the reflected wave is opposite to that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be a short-circuit fault. When the polarity of the reflected wave is the same as that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be an open circuit fault.

[0077] First, determine the polarity of the incident wave of the fault location pulse wave, and then detect the polarity of the reflected wave to be identified. Since the reflection coefficient β is determined by the change in equivalent wave impedance at the fault location of the line, different fault types will cause β to have different signs, thus resulting in a corresponding change in the polarity of the reflected wave.

[0078] When the polarity of the reflected wave is opposite to that of the incident wave, the fault type corresponding to the reflected wave is determined to be a short-circuit fault. In this case, the reflection coefficient β is less than zero, the equivalent wave impedance at the fault location is lower than the wave impedance corresponding to the incident wave path, and the reflected wave exhibits polarity reversal. For short-circuit faults such as ground faults and phase-to-phase faults, this polarity change can be used as a primary basis to determine if it is a short-circuit fault.

[0079] When the polarity of the reflected wave matches that of the incident wave, the fault type corresponding to the reflected wave is determined to be an open circuit fault. In this case, the reflection coefficient β is greater than zero, the reflected wave maintains the same polarity as the incident wave, and the fault location exhibits a large equivalent impedance characteristic.

[0080] In practical processing, polarity can be used to first classify fault types into broad categories, and then the specific fault type can be further determined by combining the reflected wave amplitude, time delay, and waveform distortion. Using polarity as the first-level judgment criterion can still retain relatively clear fault discrimination information even when the reflected wave amplitude is affected by line attenuation or acquisition noise, thereby improving the ability to distinguish between short-circuit faults and open-circuit faults.

[0081] In some embodiments, determining the fault type corresponding to the fault reflection wave based on the matching result includes: When the amplitude of the reflected wave is close to that of the incident wave, and the waveform of the reflected wave shows obvious abrupt change characteristics, the fault type is determined to be a low-resistance short-circuit fault. When the amplitude of the reflected wave is lower than that corresponding to a low-resistance short-circuit fault, and the waveform of the reflected wave exhibits a wide range of variation, the fault type is determined to be a medium-resistance short-circuit fault. When the amplitude of the reflected wave decreases further and the waveform of the reflected wave shows a slow change, the fault type is determined to be a high-resistance grounding fault. When the amplitude of the reflected wave is close to that of the incident wave, and the polarity of the reflected wave is the same as that of the incident wave, the fault type is determined to be an open circuit fault.

[0082] The implementation methods for further distinguishing low-resistance short-circuit faults, medium-resistance short-circuit faults, high-resistance ground faults, complete open-circuit faults, and incomplete open-circuit faults are based on the amplitude and waveform distortion characteristics of the reflected wave.

[0083] For low-resistance short-circuit faults, the transition resistance at the fault location is small, and the fault reflected wave exhibits strong amplitude variations. The amplitude of the reflected wave is approximately 60%-80% of the incident wave amplitude. The polarity of the reflected wave is reversed, manifesting as a sharp distortion peak and a steep rising edge. Therefore, when a polarity reversal is detected in the reflected wave, the amplitude is within the corresponding range, and the waveform exhibits a sharp peak, the reflected wave can be identified as the fault reflected wave corresponding to a low-resistance short-circuit fault.

[0084] For medium-resistance short-circuit faults, the fault transition resistance increases relatively, and the amplitude of the reflected wave decreases accordingly, typically accounting for about 30%-60% of the incident wave amplitude. At the same time, the peak value of the waveform is wider and gentler than that of a low-resistance short circuit, and the rising edge is slower. When a polarity reversal of the reflected wave is detected, the amplitude is within the corresponding range, and a wide distortion peak is observed, it can be determined that it is a medium-resistance short-circuit fault.

[0085] For high-resistance grounding faults, the fault transition resistance further increases, and the amplitude of the reflected wave further decreases, typically accounting for about 10%-30% of the incident wave amplitude. The reflected wave still exhibits polarity reversal, but its waveform distortion peak is relatively flat. Therefore, the reduction in reflected wave amplitude and the flattening of waveform change can be used as joint identification characteristics of high-resistance grounding faults.

[0086] For a complete open-circuit fault, the polarity of the reflected wave is the same as that of the incident wave, and the amplitude of the reflected wave is about 80%-95% of the amplitude of the incident wave. Its amplitude is close to that of the incident wave, and the waveform has basically no obvious distortion. When the polarity is consistent, the amplitude is close to that of the incident wave, and the waveform has basically no distortion, it can be determined as a complete open-circuit fault.

[0087] For incomplete circuit breaker faults, the polarity of the reflected wave is the same as that of the incident wave, but the amplitude of the reflected wave is usually about 40%-80% of the amplitude of the incident wave, and its amplitude varies with the degree of circuit breaker. Therefore, incomplete circuit breaker faults can be further distinguished by the correspondence between the amplitude of the reflected wave and the degree of circuit breaker.

[0088] The above judgment is not based solely on a single fixed value, but rather on a comprehensive matching of the polarity, amplitude range, peak value, and rising edge variation of the reflected wave. Since the amplitude of the reflected wave generally decreases as the fault transition resistance increases, and the waveform distortion becomes smoother, a continuous fault characteristic can be formed, progressing from low-resistance short circuits and medium-resistance short circuits to high-resistance grounding.

[0089] In some embodiments, determining the propagation delay of the fault reflected wave based on the fault reflected wave, and determining the fault location based on the propagation delay, includes: When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector. When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector, where k is a positive integer greater than 1. When the propagation delay of the fault reflected wave is greater than the reference propagation delay corresponding to the last connector, the fault location is determined to be in the area of ​​the end power supply line.

[0090] After identifying the fault reflection wave, the propagation delay of the fault reflection wave from the pulse input position to the fault location and back to the detection position is obtained. Since the positions of each cable joint in the traction power supply network are known, and the propagation characteristics of the fault location pulse wave in different line sections can be determined by the electrical parameter model, the reference propagation delay corresponding to each joint can be obtained in advance.

[0091] When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector. At this time, the fault reflected wave has already returned before reaching the first connector, so the fault point is located between the first connector and the pulse input position.

[0092] When the propagation delay of the fault reflected wave lies between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be within the power supply line area between the k-th connector and the (k+1)-th connector. Here, the k-th connector can be a connector numbered sequentially along the propagation direction of the fault location pulse wave, where k is a positive integer greater than 1.

[0093] When the propagation delay of the fault reflected wave is greater than the reference propagation delay corresponding to the last joint, the fault location is determined to be in the area of ​​the end power supply line. Therefore, the entire traction power supply network can be divided into different fault sections using the propagation delay, and then specific distance calculations can be performed within the corresponding sections.

[0094] This method of determining the fault section based on the reference propagation delay of the joint can adapt to situations where there are multiple joints in the traction power supply network. Especially when the fault is located after an intermediate joint, the arrival time of the fault reflection wave will be later than the inherent reflection wave of the preceding joint, so the fault section can be identified by using the time sequence.

[0095] The incident and reflected waves at four different fault locations are compared below: The waveform under fault-free operating conditions, such as Figure 4 As shown, only the inherent reflected waves of each level of joint exist, with no fault reflection component; the amplitude of the reflected wave is approximately 15%-20% of the incident wave, the polarity is consistent with the incident wave, the waveform is smooth and undistorted, and the time delay is equal to t. 0i .

[0096] Waveform of open circuit fault in intermediate joint, such as Figure 5 As shown, the time delay of the reflected wave from the first connector is still [value missing]. However, the amplitude increased significantly, the waveform showed slight distortion, and there was a clear difference from the inherent reflected wave of the joint.

[0097] The waveform of the short-circuit fault condition before the intermediate joint is as follows: Figure 6 As shown, the fault-reflected wave arrives earlier than all joint-reflected waves. When the polarity is completely reversed from the incident wave, the amplitude increases sharply, and the waveform shows a sharp distortion peak. All subsequent joint reflected waves are covered by the fault wave and cannot be identified.

[0098] The waveform of the short-circuit fault condition after the intermediate joint is as follows: Figure 7 As shown, the inherent reflected wave of the first connector appears first ( ), and then a fault reflection wave appeared ( The polarity reversal, amplitude abnormality, and waveform distortion of the fault reflected wave require the removal of interference from the first joint reflected wave before location calculation.

[0099] In some embodiments, when the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, determining that the fault location is in the power supply line area before the first connector includes: The fault location is determined based on the propagation time delay of the reflected fault wave and the calibrated wave velocity. The expression for the fault location is: ; When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector, including: The fault location is determined based on the propagation delay of the k-th connector and the position of the k-th connector. The expression for the fault location is: ; in, The fault location is V, the calibrated wave velocity is V, and the propagation delay of the fault reflected wave is t. Let the reference propagation delay be the k-th connector. This represents the position of the k-th connector.

[0100] When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector. In this case, the fault location pulse wave propagates from the detection location to the fault point and then returns. There is no propagation distance of the preceding connector that needs to be deducted in the propagation path. Therefore, the fault location is determined based on the propagation delay of the fault reflected wave and the calibrated wave velocity, and its expression is: .

[0101] Here, dividing by 2 is because t represents the time taken for the fault location pulse wave to travel back and forth, while This corresponds to a single-way propagation distance. The calibrated wave velocity V can be determined based on the actual traction power supply network line parameters and detection conditions to reduce positioning errors caused by directly using the theoretical propagation velocity.

[0102] When the propagation delay of the fault reflected wave lies between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be between the k-th connector and the (k+1)-th connector. At this point, the fault location pulse wave has already passed the k-th connector, therefore the total round-trip propagation delay t includes the round-trip delay to reach the k-th connector. To calculate the fault distance after the k-th joint, it is necessary to subtract it from the total propagation delay. Then, using the calibrated wave velocity V, the one-way distance from the k-th connector to the fault point is calculated, and the position of the k-th connector is added. Therefore, the fault location expression is: .

[0103] in, The fault location is V, the calibrated wave velocity is V, and the propagation delay of the fault reflected wave is t. Let the reference propagation delay be the k-th connector. Let k be the position of the k-th connector, where k is a positive integer greater than 1.

[0104] Using the two calculation relationships described above, fault locations can be calculated for cases where the fault is located before the first joint and for cases where the fault is located between any two adjacent joints. Compared to directly calculating the distance using the total propagation delay, subtracting the reference propagation delay of the preceding joint can avoid the cumulative distance error caused by the multi-stage joint structure, thereby improving the accuracy of fault location calculation in multi-joint non-uniform lines.

[0105] Figure 8 This is a schematic diagram of a power supply fault location device provided by the present invention. The power supply fault location device includes: Memory 21 is used to store computer programs; The processor 22 is used to implement the steps of the above-described method for locating power supply faults when executing a computer program.

[0106] In some embodiments, it also includes: The input interface, connected to the processor, is used to acquire externally imported computer programs, parameters, and commands, and saves them to memory under the control of the processor. The display unit, connected to the processor, is used to display the data sent by the processor; The network port is connected to the processor and is used for communication with various external terminal devices.

[0107] This input interface can be connected to an input device to receive parameters or commands manually entered by the user. This input device can be a touch layer covering the display screen, or it can be a button, trackball, or touchpad located on the terminal casing.

[0108] The display unit can be an LCD screen or an e-ink screen, etc.

[0109] The communication technology used in this connection can be wired or wireless, such as MHL (Mobile High-Definition Link), USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface), WiFi (Wireless Fidelity), Bluetooth, and Bluetooth Low Energy.

[0110] The description of the power supply fault location device provided in this application is given in the above embodiments and will not be repeated here.

[0111] Figure 9 This is a schematic diagram of a power supply fault location system provided by the present invention. The power supply fault location system includes the aforementioned power supply fault location device, and further includes: The pulse signal generating module is connected to the power supply fault location device and is used to input fault location pulse waves into the traction power supply network; The data acquisition module is connected to the power supply fault location device and is used to collect reflected wave data in the traction power supply network.

[0112] The pulse signal generation module is used to input fault location pulse waves into the traction power supply network. The module can generate standard fault location pulse waves based on control commands output by the power supply fault location device and then apply these pulse waves to the traction power supply network. The input pulse waves propagate along the feeder cable, power supply cable, and stator winding cable, and produce different forms of reflection at cable joints, busbars, and fault locations.

[0113] The data acquisition module is used to collect reflected wave data from the traction power supply network. After receiving a pulse from the pulse signal generator module, the data acquisition module samples the voltage changes in the traction power supply network and sends the acquisition results to the power supply fault location device. The acquisition results can include the amplitude, polarity, time position, and waveform change information of the original reflected wave.

[0114] Figure 9The fault injection module adds fault modules to different stator winding cable positions in the traction power supply network simulation model to simulate faults such as stator winding cable grounding, phase-to-phase short circuit, and open circuit. It can also modify the equivalent resistance and capacitance parameters of the cable to ground at different positions to simulate the decline in line insulation level, record the propagation law and reflection wave characteristics of incident waves under different faults, and obtain the reflection wave law of different fault types such as low-resistance short circuit, medium-resistance short circuit, high-resistance grounding, complete open circuit or incomplete open circuit.

[0115] like Figure 9 As shown, the signal flow of the fault location system can be represented as follows: the pulse signal generation module generates a fault location pulse wave and inputs it into the line model; the data acquisition module acquires the reflected wave data formed during the propagation process; the power supply fault location device analyzes the reflected wave data and obtains the fault location result through dynamic compensation and position calculation; and finally, the waveform display module outputs the processing result.

[0116] In some embodiments, it also includes: The waveform display module is connected to the power supply fault location device and is used to display the waveform of the original reflected wave, the waveform of the processed reflected wave, and the fault location mark.

[0117] The waveform display module displays the waveform of the original reflected wave, the waveform of the processed reflected wave, and the fault location indicator. The power supply fault location device processes the original reflected wave data acquired by the data acquisition module and sends the processing result to the waveform display module. The waveform display module then simultaneously presents the original data and the processing result, allowing maintenance personnel to observe the waveform changes before and after compensation, as well as the fault location result.

[0118] The waveform display module is an auxiliary module and has the following functions: The waveform of the original acquired reflected wave and the preprocessed waveform after wavelet denoising are displayed in real time. Mark the location and amplitude of reflected waves from each level of joint; Highlight the filtered fault reflection waves and mark their time delay and calculated fault location; It supports waveform zooming, saving, and printing functions, making it convenient for maintenance personnel to archive and analyze data.

[0119] Please refer to the above embodiments for a description of the power supply fault location system provided in this application, and it will not be repeated here.

[0120] This application also provides a train, including the aforementioned power supply fault location system, and further comprising: The traction power supply network, connected to the power supply fault location system, is used to provide traction power to the train.

[0121] In some embodiments, the traction power supply network includes traction substations, feeder cables, stator switch stations, feeder cables, and stator section winding cables; The traction substation is connected to the feeder cable and is used to output traction power. The feeder cable connects to the stator switch station and is used to transmit traction power. The stator switch station is connected to the feeder cable and is used to control the transmission of traction power to different stator sections; The feeder cable is connected to the stator winding cable and is used to provide traction power to the corresponding stator winding of the train.

[0122] like Figure 10 As shown, the traction power supply network adopts a segmented power supply structure with a long stator. The traction power output from the traction substation is transmitted to the corresponding stator winding cables via feeder cables, stator switch station, and feeder cables. The stator winding cables then supply power to the corresponding stator windings. The stator switch station controls the activation of the corresponding power supply lines based on the power supply section where the train is located, ensuring that the stator windings in the train's operating area receive traction power. The two output terminals of the traction substation output voltage to the feeder cables. The stator switch station can choose to close either the star junction switch or the feeder switch to determine whether the stator winding cables are connected to the feeder cables.

[0123] When the power supply fault location system is connected to the traction power supply network, it can input fault location pulse waves into the traction power supply network when line fault detection is required, and acquire the reflected waves returned by the line through the data acquisition module. Since the power supply fault location system adopts an electrical parameter model corresponding to the traction power supply network, it can analyze the reflected waves generated by the feeder cable, stator section winding cable, cable joint, and busbar.

[0124] When a ground fault, phase-to-phase short circuit, open circuit, or other line anomaly occurs in the traction power supply network, the fault location will cause changes in the equivalent parameters of the line. After the fault location pulse wave propagates to the fault location, it generates a fault reflection wave. This fault reflection wave is analyzed by the power supply fault location system to determine the fault type and fault location.

[0125] By installing a power supply fault location system in relevant train equipment, fault location information of the traction power supply network can be obtained during train operation and maintenance. For faults requiring power outage repair, the actual inspection scope can be narrowed down based on the fault location results, reducing the time required to search for the fault point segment by segment along the line.

[0126] The traction substation supplies electrical energy to the stator windings through a long stator linear motor power supply system. The stator windings generate a traveling wave magnetic field and interact with the on-board magnetic poles to generate the traction force required for train operation.

[0127] The traction substation is connected to the feeder cable and is used to output traction power. The traction substation receives electrical energy from the power supply side and transforms and processes it to form traction power for high-speed maglev traction. As the power source for the traction power supply network, the output end of the traction substation is connected to the feeder cable, enabling the traction power to be transmitted along the line.

[0128] The feeder cable connects to the stator switch station and is used to transmit traction power. The feeder cable delivers the traction power output from the traction substation to the stator switch station located along the line. Because the feeder cable is a long-distance power supply line, its line parameters affect the transmission characteristics of the traction power, and also affect the propagation speed, waveform, and reflection characteristics of the fault location pulse wave.

[0129] The stator switching station is connected to the feeder cables and is used to control the transmission of traction power to different stator sections. The stator switching station switches the appropriate power supply path based on the train's location and the power supply needs of the stator section, allowing traction power to enter the corresponding feeder cable. Through segmented power supply, different line sections can receive the appropriate power supply based on the train's operating position.

[0130] The feeder cable connects to the stator section winding cable to provide traction power to the corresponding stator winding of the train. The feeder cable transmits the traction power output from the stator switching station to the corresponding stator section winding cable, which is then further connected to the stator winding, allowing the traction power to enter the corresponding stator winding.

[0131] The train described in this application is based on the above embodiments and will not be repeated here.

[0132] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0133] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0134] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for locating power supply faults, characterized in that, The traction power supply network includes feeder cables, stator winding cables, cable joints, and busbars. The method for locating power supply faults includes: Determine the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and the stator section winding cable; Obtain the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and the busbar. A π-type equivalent circuit is established based on the cable equivalent inductance, the cable equivalent capacitance, the cable insulation resistance parameters, the interface equivalent inductance, the interface equivalent capacitance, and the interface equivalent resistance parameters; The electrical parameter model is established based on the π-type equivalent circuit. Input a fault location pulse wave into the traction power supply network and obtain the propagation data of the fault location pulse wave in the electrical parameter model; The reflected wave data is determined based on the propagation data, and the fault reflected wave is determined based on the reflected wave data; The fault type is determined based on the fault reflection wave; The propagation delay of the fault reflected wave is determined based on the fault reflected wave, and the fault location is determined based on the propagation delay.

2. The method for locating power supply faults as described in claim 1, characterized in that, Determining the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the feeder cable and the stator section winding cable includes: Based on the structural parameters of the feeder cable and the stator section winding cable, the equivalent inductance, equivalent capacitance, and insulation resistance parameters of the cable are determined. The expression for the equivalent inductance per unit length of the cable is: ； in, R is the equivalent inductance per unit length of cable, R is the radius of the grounding aluminum foil, and r is the radius of the cable core. The permeability of free space, Relative permeability; The expression for the equivalent capacitance per unit length of cable is: ； in, The equivalent capacitance per unit length of cable. The vacuum permittivity, It is the relative permittivity; The expression for the insulation resistance of the cable is: ； in, The insulation resistance per unit length of cable. The unit insulation resistance value at 20℃ This is the temperature coefficient.

3. The method for locating power supply faults as described in claim 1, characterized in that, Obtaining the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the cable connector and the busbar includes: Determine the equivalent inductance, equivalent capacitance, and equivalent resistance parameters of the interface based on the structural parameters of the cable joint and busbar. The formula for calculating the equivalent inductance of the interface is as follows: ； The formula for calculating the equivalent capacitance of the interface is as follows: ； The formula for calculating the equivalent resistance of the interface is: ； in, The equivalent inductance per unit length of the interface, This is the inductance correction factor. Based on the basic inductance parameters, The equivalent capacitance per unit length of the interface. This is the capacitance correction factor. Based on the basic capacitance parameters, The equivalent resistance per unit length of the interface. This is the resistance correction factor. These are the basic resistance parameters.

4. The method for locating power supply faults as described in claim 1, characterized in that, Inputting a fault location pulse wave into the traction power supply network and acquiring the propagation data of the fault location pulse wave in the electrical parameter model, including: The standard fault location pulse wave is determined as the incident wave; Based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations of the line structure are obtained. The reflected wave characteristics corresponding to different line structure positions are determined based on the reflected wave and the refracted wave. The reflected wave characteristics include the reflected wave amplitude, the polarity of the reflected wave, the reflected wave time delay, and the waveform changes of the reflected wave.

5. The method for locating power supply faults as described in claim 4, characterized in that, Based on the propagation process of the incident wave in the electrical parameter model, the reflected and refracted waves generated by the incident wave at different locations in the line structure are obtained, including: Based on the change in wave impedance when the incident wave passes through the connection position between lines with different wave impedances, determine the voltage of the reflected wave and the voltage of the refracted wave corresponding to the incident wave. The expression for the voltage of the refracted wave is: ； The expression for the voltage of the reflected wave is: ； The wave impedance of the first line is The wave impedance of the second line is The voltage of the incident wave is The voltage of the reflected wave is The voltage of the refracted wave is The voltage refractive index is The voltage reflection coefficient is .

6. The method for locating power supply faults as described in claim 1, characterized in that, Determining reflected wave data based on the propagation data, and determining fault reflected waves based on the reflected wave data, includes: Based on the line parameters corresponding to the cable joints and busbars in the electrical parameter model, determine the reflected voltage corresponding to the joint reflected wave; The dynamic compensation parameters are determined based on the reflected voltage. The identified joint reflection wave is compensated according to the dynamic compensation parameters to eliminate the influence of the joint reflection wave on the fault reflection wave; The fault reflection wave is determined based on the compensated reflection wave data.

7. The method for locating power supply faults as described in claim 1, characterized in that, Determining the fault type based on the fault reflection wave includes: The reflected wave data is matched according to the fault reflected wave characteristics corresponding to the preset fault type; The fault type corresponding to the fault reflection wave is determined based on the matching results; The fault reflection wave characteristics include fault type, fault location, reflection wave amplitude, reflection wave polarity, reflection wave time delay, and waveform distortion characteristics.

8. The method for locating power supply faults as described in claim 7, characterized in that, The fault type corresponding to the fault reflection wave is determined based on the matching results, including: When the polarity of the reflected wave is opposite to that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be a short-circuit fault. When the polarity of the reflected wave is the same as that of the incident wave, the fault type corresponding to the fault reflected wave is determined to be an open circuit fault.

9. The method for locating power supply faults as described in claim 8, characterized in that, The fault type corresponding to the fault reflection wave is determined based on the matching results, including: When the amplitude of the reflected wave is close to the amplitude of the incident wave, and the waveform of the reflected wave shows obvious abrupt change characteristics, the fault type is determined to be a low-resistance short-circuit fault. When the amplitude of the reflected wave is lower than the amplitude corresponding to a low-resistance short-circuit fault, and the waveform of the reflected wave exhibits a wide amplitude variation, the fault type is determined to be a medium-resistance short-circuit fault. When the amplitude of the reflected wave further decreases and the waveform of the reflected wave exhibits a slow change characteristic, the fault type is determined to be a high-resistance grounding fault. When the amplitude of the reflected wave is close to the amplitude of the incident wave, and the polarity of the reflected wave is consistent with the polarity of the incident wave, the fault type is determined to be an open circuit fault.

10. The method for locating power supply faults as described in any one of claims 1 to 9, characterized in that, Determining the propagation delay of the fault reflected wave based on the fault reflected wave, and determining the fault location based on the propagation delay, includes: When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector. When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector, where k is a positive integer greater than 1. When the propagation delay of the fault reflected wave is greater than the reference propagation delay corresponding to the last connector, the fault location is determined to be in the area of ​​the end power supply line.

11. The method for locating power supply faults as described in claim 10, characterized in that, When the propagation delay of the fault reflected wave is less than the reference propagation delay corresponding to the first connector, the fault location is determined to be in the power supply line area before the first connector, including: The fault location is determined based on the propagation delay of the fault reflected wave and the calibrated wave velocity. The expression for the fault location is: ； When the propagation delay of the fault reflected wave is between the reference propagation delay corresponding to the k-th connector and the reference propagation delay corresponding to the (k+1)-th connector, the fault location is determined to be in the power supply line area between the k-th connector and the (k+1)-th connector, including: The fault location is determined based on the propagation delay of the k-th connector and the position of the k-th connector. The expression for the fault location is: ； in, The fault location is V, the calibrated wave velocity is V, and the propagation delay of the fault reflected wave is t. Let the reference propagation delay be the k-th connector. This represents the position of the k-th connector.

12. A device for locating power supply faults, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the power supply fault location method as described in any one of claims 1 to 11 when executing the computer program.

13. The power supply fault location device as described in claim 12, characterized in that, Also includes: An input interface, connected to the processor, is used to acquire externally imported computer programs, parameters, and commands, and save them to the memory under the control of the processor. The display unit, connected to the processor, is used to display the data sent by the processor; The network port is connected to the processor and is used for communication with external terminal devices.

14. A system for locating power supply faults, characterized in that, The device for locating power supply faults as described in claim 12 or 13 further includes: A pulse signal generating module is connected to the power supply fault location device and is used to input fault location pulse waves to the traction power supply network; The data acquisition module is connected to the power supply fault location device and is used to collect reflected wave data in the traction power supply network.

15. The power supply fault location system as described in claim 14, characterized in that, Also includes: The waveform display module is connected to the power supply fault location device and is used to display the waveform of the original reflected wave, the waveform of the processed reflected wave, and the fault location marker.

16. A train, characterized in that, The system for locating power supply faults as described in claim 14 or 15 further includes: The traction power supply network, connected to the power supply fault location system, is used to provide traction power to the train.

17. The train as described in claim 16, characterized in that, The traction power supply network includes traction substations, feeder cables, stator switch stations, feeder cables, and stator section winding cables; The traction substation is connected to the feeder cable and is used to output traction power. The feeder cable is connected to the stator switch station and is used to transmit the traction power supply. The stator switch station is connected to the feeder cable and is used to control the transmission of traction power to different stator sections; The feeder cable is connected to the stator winding cable and is used to provide traction power to the stator winding corresponding to the train.

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