A method and system for directly supplying fault distance measurement on double-track electrified railway

Abstract

The present invention discloses a method and system for measuring fault distance of a double-track electrified railway direct supply. The method accurately calculates the fault distance by judging the operation mode of the uplink and downlink lines on the basis of the piecewise linear reactance method. When the line fault occurs, the uplink and downlink feeder circuit breakers are both in the closed position and the incremental current is measured at the same time, it is judged to be in parallel operation mode, and the fault distance is calculated by the parallel operation mode modified reactance method; when the line fault occurs, the uplink and downlink feeder circuit breakers are both in the closed position and only one line measures the incremental current, it is judged to be in the decoupling operation mode, and the fault distance is calculated by the piecewise linear reactance method. The present invention overcomes the influence of mutual inductance on fault distance measurement under the direct supply mode of the double-track electrified railway, improves the accuracy of the reactance distance measurement method under the double-track direct supply fault, is applicable to both direct supply and terminal parallel conditions, ensures the accuracy of the reactance distance measurement of the entire line, and reduces the workload of on-site personnel in finding faults.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrified railway traction power supply, and in particular relates to a method, system and equipment for direct supply fault distance measurement of double-track electrified railway based on iterative approximation. Background Art

[0002] Double-track direct supply is a power supply method in which the traction power supply system supplies power to both upstream and downstream, does not contain autotransformers, and under normal circumstances, the substations are connected in parallel in both upstream and downstream. In order to increase the voltage level of the overhead line and reduce power losses, the double-track direct supply lines of electrified railways generally adopt the operation mode of parallel connection of the power supply arm ends in both upstream and downstream directions. The direct supply method generally uses the reactance method for distance measurement. When operating on a single line, the conventional reactance method is more accurate in distance measurement. However, when operating in parallel at the end, the influence of the mutual inductance of the upstream and downstream lines cannot be ignored, resulting in large errors in the conventional reactance method.

[0003] Chinese patent application CN202010683804.1 discloses a fault ranging method for a fully parallel AT traction network, comprising the following steps: when a fault occurs, synchronously collecting the status of the up and down bipolar feeder circuit breakers of each booth and the current flowing through the circuit breakers to construct a traction network parallel state matrix and a feeder current matrix; constructing a current state matrix and a fault state matrix; determining whether the fault section is an up and down parallel section before ranging, or determining whether the fault section is a single-line AT section before ranging, or determining the fault type before ranging.

[0004] Patent application CN202211349388.7 discloses a fault ranging system and method for a double-track traction network with bilateral direct power supply, including: a first feeder current detection module, a second feeder current detection module, a clock synchronization module, a data exchange channel module, a first current ratio calculation module, a second current ratio calculation module, a first fault distance calculation module and a second fault distance calculation module; the method implements the fault uplink and downlink judgment logic and fault ranging of the double-track traction network with bilateral direct power supply.

[0005] However, if the above patented technical solution is applied to a double-line direct-powered traction network, it is necessary to configure dedicated traction network fault ranging devices and communication equipment in each traction station, AT station, and substation along the traction network. Any problem with any dedicated ranging device or equipment will cause the fault ranging system to lose its function, resulting in reduced reliability of traction network fault ranging. In addition, the method is not simple enough, is not convenient for on-site adjustment, and has low engineering practicality. Summary of the invention

[0006] In order to solve the technical problem in the prior art that the fault distance measurement of a double-track direct-supply traction power supply system is inaccurate due to the influence of the mutual inductance of the uplink and downlink lines, the present invention provides a double-track electrified railway direct-supply fault distance measurement method, a fault distance measurement system, and a fault distance measurement device with accurate calculation and convenient maintenance, so as to solve the problem of large distance error in conventional reactance method when a fault occurs when the double-track direct-supply power supply mode is operated in parallel.

[0007] To achieve the above-mentioned invention object, the present application discloses a method for directly supplying fault distance measurement on a double-track electrified railway, comprising the following steps:

[0008] Step 1: Upstream and downstream feeder protection devices respectively collect the bus voltage of the traction substation, the position signal of the feeder circuit breaker of each line, and the current of each line feeder in real time;

[0009] Step 2, judging the fault category according to the bus voltage, feeder circuit breaker position signal and feeder current, the fault category is the feeder protection device of this category combined with the current increment flag issued by the feeder protection device of another category to judge the traction power supply operation mode at the time of the fault; when the current increment value of the other category is greater than or equal to the increment threshold, the current increment flag is set, otherwise the current increment flag is not set;

[0010] Step 3, calculate the fault distance according to the operation mode: if the upper and lower lines are in separate operation, the fault distance is calculated using the piecewise linear reactance method; if the upper and lower lines are in parallel operation, the fault distance is calculated using the modified reactance method; where the fault distance is the distance from the short-circuit point to the exit of the traction substation.

[0011] More preferably,

[0012] In step 2, when the feeder circuit breaker is in the closed position, the line feeder protection device to which the circuit breaker belongs determines whether a fault occurs in the line feeder based on the bus voltage and the line feeder current, based on distance protection and current quick-break protection.

[0013] More preferably,

[0014] In step 2, the current increment flag sent by another feeder protection device includes:

[0015] When another feeder protection device determines that the current increment of the feeder current exceeds a preset threshold, the current increment flag is set to 1, and the device is connected to the feeder protection device of the same line through the device outlet, or a goose message is sent through the network interface and the feeder protection device of the same line subscribes to goose;

[0016] The conditions for setting the current increment flag are as follows:

[0017] △ I 2≥ Ith

[0018] △I2=I2h—I2q

[0019] Among them, △ I 2 is the increment of the effective value of the two adjacent cycles of current of another feeder at the time of fault. Ith is the increment threshold, I 2 h is the effective value of the current of the latter cycle among two adjacent cycles of another feeder line, I 2 q It is the effective value of the current in the previous cycle.

[0020] More preferably,

[0021] The step 2 of determining the traction power supply operation mode at the time of the fault includes:

[0022] When the feeder protection device of this line detects a line fault and the current increment flag issued by the feeder protection device of another line is set, it is judged to be in parallel operation mode; when the feeder protection device of this line detects a line fault, but the current increment flag issued by the feeder protection device of another line is not set, it is judged to be in de-parallel operation mode.

[0023] More preferably,

[0024] In step 3, the fault distance calculated by the piecewise linear reactance method is L x for:

[0025] ,

[0026] in, L x is the fault distance, X f The measured reactance value calculated by the feeder protection device at the moment of the fault for the fault line; X m The feeder protection device is set to m Segment start reactance, X m+1 For the setting m The end-of-segment reactance, L m For the setting m The starting distance of the segment, L m+1 For the setting m The end distance of the segment always satisfies X m+1 > X m ,and L m+1 > L m, 1≤ m ≤ N -1, L N Equal to the total length of the line L .

[0027] More preferably,

[0028] In step 3, the first Fault distance after iterations :

[0029] ,

[0030] ,

[0031] in, X 1. L 1 are the initial primary measurement reactance and fault distance, X f is the measured reactance value calculated by the feeder protection device at the time of the fault, X k-1 , L k-1 Respectively k -1 iteration to obtain the primary reactance and fault distance, X m , X n The adjusted m Section n The starting reactance value of the segment, L m For the setting m The starting distance of the segment, L m+1 For the setting m Segment end distance, L n For the setting n The starting distance of the segment, L n+1 For the setting n Segment end distance, x m is the unit mutual reactance between lines.

[0032] The second aspect of the present application discloses a double-track electrified railway direct supply fault distance measurement system based on the above-mentioned distance measurement method, comprising:

[0033] Sampling module, used to collect bus voltage of traction substation and current signals of feeder of the same line in real time;

[0034] The fault and operation mode identification module is used to determine the fault type according to the bus voltage, feeder circuit breaker position signal and feeder current, and to determine the traction power supply operation mode in combination with the current increment sign issued by the feeder protection device of another type;

[0035] The fault distance calculation module calculates the fault distance according to the traction power supply operation mode, that is, when the uplink and downlink feeders are separated, the fault distance is calculated according to the piecewise linear reactance method, and when the uplink and downlink feeders are parallel, the fault distance is calculated according to the modified reactance method.

[0036] More preferably,

[0037] The fault and operation mode identification module includes a fault identification submodule and an operation mode identification submodule;

[0038] The fault determination submodule determines whether a fault occurs in the feeder of the same line based on distance protection and current quick-break protection;

[0039] The operation mode determination submodule receives the current increment flag issued by another row feeder protection device. When the row feeder protection device detects that a line fault has occurred and the current increment flag issued by another row feeder protection device is set, it is determined to be in parallel operation mode; when the row feeder protection device detects that a line fault has occurred, but the current increment flag issued by another row feeder protection device is not set, it is determined to be in de-parallel operation mode.

[0040] More preferably,

[0041] The fault distance calculation module includes a piecewise linear reactance method distance measurement submodule and a modified reactance method distance measurement submodule;

[0042] The piecewise linear reactance distance measurement submodule calculates the fault distance according to the piecewise linear reactance method, and calculates the measured reactance value according to the bus voltage and feeder current. When the measured reactance value is within the reactance range of a certain segment, the fault distance is calculated according to the segment reactance and segment kilometers set by the feeder protection device;

[0043] The corrected reactance distance measurement module calculates the fault distance by the corrected reactance method. The measured reactance value is calculated according to the bus voltage at the time of the fault and the feeder current of the fault line, and the piecewise linear reactance fault distance is calculated. The reactance component caused by the mutual inductance is calculated based on the distance, and the influence of this component is removed through repeated iterations, thereby realizing the correction of the fault distance and obtaining an accurate fault distance.

[0044] The present application also discloses a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, and when the instructions are executed by a computing device, the computing device executes a direct fault distance measurement method for a double-track electrified railway.

[0045] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing a direct fault distance measurement method for a double-track electrified railway based on iterative approximation.

[0046] The beneficial effects achieved by the present invention are:

[0047] 1. The present invention removes the reactance component caused by the mutual inductance from the measured reactance to correct the reactance method of the parallel connection of the double-line direct supply, which greatly improves the accuracy of the double-line direct supply fault reactance method distance measurement;

[0048] 2. The present invention only needs to set parameters such as linear reactance meter, mutual inductance, line length, etc., which reduces the workload of on-site operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Provides direct fault distance measurement process of reactance method for double-track electrified railway.

[0050] Figure 2 This is the mesh diagram of the double-line direct supply downstream fault current.

[0051] Figure 3 It is a diagram for sending and receiving incremental marks for the upstream and downstream feeder protection devices of the traction substation. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0053] like Figure 1 As shown, the double-track electrified railway direct supply fault location method based on iterative approximation of the present invention comprises the following steps:

[0054] (1) The upstream and downstream feeder protection devices respectively collect the bus voltage on the 25kV side of the traction substation, the position signal of the feeder circuit breaker of the line, and the current of the feeder of the line in real time;

[0055] (2) Determine the fault row based on the bus voltage and feeder current, and determine the traction power supply operation mode at the time of the fault in combination with the current increment sign issued by the feeder protection device of another row: when the current increment value of another row is greater than 80A, it is determined to be in parallel operation mode; when the current increment value of another row is less than 80A, it is determined to be in disconnection operation mode;

[0056] (3) Calculate the fault distance according to the operation mode: If the upper and lower lines are operated in a disconnected manner, the fault distance is calculated using the piecewise linear reactance method; if the upper and lower lines are operated in parallel, the fault distance is calculated using the modified reactance method; where the fault distance is the distance from the short-circuit point to the exit of the traction substation.

[0057] The fault distance is calculated by the piecewise linear reactance method, which means that the measured reactance value is calculated according to the bus voltage and the feeder current. When the measured reactance value is within the reactance range of a certain segment, the fault distance is calculated according to the segmented reactance and segmented kilometers set by the feeder protection device.

[0058] The fault distance is calculated according to the modified reactance method, and the measured reactance value is calculated according to the bus voltage at the time of the fault and the feeder current of the fault line, and the fault distance of the piecewise linear reactance method is calculated. The reactance component generated by the mutual inductance is calculated based on the distance, and the influence of the component is removed through repeated iterations, thereby realizing the correction of the fault distance and obtaining an accurate fault distance.

[0059] like Figure 2 The figure shows the fault current mesh diagram of the double-track direct supply upstream of the electrified railway in this embodiment, which is composed of the 25kV busbar on the traction station. B SS , the 211 downlink feeder (in this embodiment, the downlink feeder is numbered 211) circuit breaker of the traction station, the 212 uplink feeder (in this embodiment, the uplink feeder is numbered 212) circuit breaker of the traction station, the front section of the downlink traction network fault point AF , Transition resistance of the fault point of the downstream traction network R g , the downstream traction network fault point rear section FB , Upward traction network CD , Upstream and downstream traction network line unit mutual reactance x m , the parallel circuit breaker of the upstream and downstream interconnection lines (interconnection line number 281) of the substation, and the 25kV busbar of the substation B SP Composition; Among them, the total length of the uplink and downlink lines L =26km, line unit self-reactance x s =0.31Ω / km, line unit mutual reactance x m =0.078Ω / km, the actual short-circuit fault point is far from the traction substation L d =16km.

[0060] like Figure 3The figure shows the mutual transmission and reception diagram of current increment marks of the upstream and downstream feeder protection devices of the traction substation in this embodiment, which is composed of a downstream 211 feeder protection device and its sending (TX) and receiving (RX) modules, an upstream 212 feeder protection device and its sending (TX) and receiving (RX) modules, and physical links between the devices; wherein the sending and receiving modules include: an export node, an input hard node, or a network interface with sending and receiving functions.

[0061] based on Figure 2 The grid diagram of the direct supply upstream fault current of the double-track electrified railway shown in the figure, and Figure 3 The figure shows the current increment sign mutual transmission and reception diagram of the upstream and downstream feeder protection devices of the traction substation in this embodiment. The method for direct supply fault distance measurement of double-track electrified railway of the present invention comprises the following steps:

[0062] Step 1: The upstream and downstream feeder protection devices respectively collect the bus voltage on the 25kV side of the traction substation, the position signal of the feeder circuit breaker of the line, and the feeder current of the line in real time.

[0063] according to Figure 2 When the downstream traction network fails, the bus voltage on the 25kV side of the traction substation is collected. U SS =13.4kV, the downstream 211 feeder circuit breaker 2 is in the closed position, and the current flowing through the downstream 211 feeder circuit breaker is I 1=2281A∠289°, the upstream 212 feeder circuit breaker is in the closed position, and the current flowing through the upstream 212 feeder circuit breaker is I 2 = 923A∠290°;

[0064] according to Figure 3 The downstream 211 feeder protection device receives the upstream 212 feeder current increment mark sent by the upstream 212 feeder protection device in real time through the transceiver module and the physical link.

[0065] Step 2: Determine the fault row based on the bus voltage and feeder current, and determine the traction power supply operation mode at the time of the fault in combination with the current increment sign emitted by the feeder protection device of another row: when the current increment value of another row is greater than 80A, it is determined to be a parallel operation mode; when the current increment value of another row is less than 80A, it is determined to be a decoupling operation mode.

[0066] according to Figure 2 and Figure 3 , when the downlink traction network fails, U SS =13.4kV, I 1=2281A∠289°, the electric quantity is within the distance protection and current quick-break protection range of the downstream 211 feeder protection device, and the downstream 211 feeder protection device is in action;

[0067] Current flowing through the upstream 212 feeder circuit breaker△ I 2>80A, the upstream 212 feeder current increment flag is set to 1, and the flag is sent to the downstream 211 feeder protection device through the physical link;

[0068] The protection device of the downstream 211 feeder is activated and at the same time receives a signal that the current increment flag of the upstream 212 feeder is set to 1. Based on this, it is judged that the traction power supply operation mode at the time of the fault is the upstream and downstream parallel operation mode.

[0069] Step 3: Calculate the fault distance according to the operation mode: if the upper and lower lines are in separate operation, the fault distance is calculated according to the piecewise linear reactance method; if the upper and lower lines are in parallel operation, the fault distance is calculated according to the modified reactance method; where the fault distance is the distance from the short-circuit point to the exit of the traction substation. Figure 2 The line parameters, fault power and steps 1 and 2, the fault distance is calculated as follows:

[0070] Based on the following linear reactance table for single-line operation, the distance measurement results of the piecewise linear reactance method obtained by using this table in parallel operation mode:

[0071] X(Ω) 0 1.86 3.72 5.58 8.06 L(km) 0 6 12 18 26

[0072] ,

[0073] ,

[0074] The ranging error at this time is:

[0075] ,

[0076] Using the modified reactance method, four iterations are performed and the ranging results are calculated as follows:

[0077] First operation:

[0078] ,

[0079] ,

[0080] Iteration 2:

[0081] ,

[0082] ,

[0083] Iteration 3:

[0084] ,

[0085] ,

[0086] Iteration 4:

[0087] ,

[0088] ,

[0089] In parallel operation mode, the ranging error of the modified reactance method is:

[0090] ,

[0091] Furthermore, in parallel operation mode, the fault distance measurement error of the modified reactance method of the present invention is within 0.1 km, which is better than the distance measurement error of 1.92 km of the piecewise linear reactance method.

[0092] The present application also discloses a double-track electrified railway direct fault distance measurement system based on the distance measurement method described in any one of claims 1 to 6, including a sampling module, a fault and operation mode identification module, and a fault distance calculation module.

[0093] Sampling module, used to collect bus voltage of traction substation and current signals of feeder of the same line in real time;

[0094] The fault and operation mode identification module is used to determine the fault type according to the bus voltage, feeder circuit breaker position signal and feeder current, and to determine the traction power supply operation mode in combination with the current increment sign issued by the feeder protection device of another type;

[0095] In a preferred embodiment of the present invention, the fault and operation mode determination module includes a fault determination submodule and an operation mode determination submodule;

[0096] The fault determination submodule determines whether a fault occurs in the feeder of the same line based on distance protection and current quick-break protection;

[0097] The operation mode determination submodule receives the current increment flag issued by another row feeder protection device. When the row feeder protection device detects that a line fault has occurred and the current increment flag issued by another row feeder protection device is set, it is determined to be in parallel operation mode; when the row feeder protection device detects that a line fault has occurred, but the current increment flag issued by another row feeder protection device is not set, it is determined to be in de-parallel operation mode.

[0098] The fault distance calculation module calculates the fault distance according to the traction power supply operation mode, that is, when the uplink and downlink feeders are separated, the fault distance is calculated according to the piecewise linear reactance method, and when the uplink and downlink feeders are in parallel, the fault distance is calculated according to the modified reactance method;

[0099] In a preferred embodiment of the present invention, the fault distance calculation module includes a piecewise linear reactance method distance measurement submodule and a modified reactance method distance measurement submodule;

[0100] The piecewise linear reactance distance measurement submodule calculates the fault distance according to the piecewise linear reactance method, and calculates the measured reactance value according to the bus voltage and feeder current. When the measured reactance value is within the reactance range of a certain segment, the fault distance is calculated according to the segment reactance and segment kilometers set by the feeder protection device;

[0101] The corrected reactance distance measurement module calculates the fault distance by the corrected reactance method. The measured reactance value is calculated according to the bus voltage at the time of the fault and the feeder current of the fault line, and the piecewise linear reactance fault distance is calculated. The reactance component caused by the mutual inductance is calculated based on the distance, and the influence of this component is removed through repeated iterations, thereby realizing the correction of the fault distance and obtaining an accurate fault distance.

[0102] Based on the same inventive concept, the present application may also be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0103] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the above. The computer-readable storage medium used herein is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0104] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0105] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect through the Internet). In some embodiments, by using the state information of the computer-readable program instructions to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit may execute the computer-readable program instructions, thereby implementing various aspects of the present disclosure.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for direct fault location measurement on double-track electrified railway, characterized in that: The steps include: Step 1: Upstream and downstream feeder protection devices respectively collect the bus voltage of the traction substation, the position signal of the feeder circuit breaker of each line, and the current of each line feeder in real time; Step 2, judging the fault category according to the bus voltage, feeder circuit breaker position signal and feeder current, the fault category is the feeder protection device of this category combined with the current increment flag issued by the feeder protection device of another category to judge the traction power supply operation mode at the time of the fault; when the current increment value of the other category is greater than or equal to the increment threshold, the current increment flag is set, otherwise the current increment flag is not set; Step 3, calculate the fault distance according to the operation mode: if the uplink and downlink feeders are operated in parallel, the fault distance is calculated according to the piecewise linear reactance method; if the uplink and downlink feeders are operated in parallel, the fault distance is calculated according to the modified reactance method; wherein the fault distance is the distance from the short-circuit point to the exit of the traction substation; The fault distance calculated by the piecewise linear reactance method L x for: Calculate the first Fault distance after iterations : in, X 1. L 1 are the initial primary measurement reactance and fault distance, X f is the measured reactance value calculated by the feeder protection device at the time of the fault, X k-1 , L k-1 Respectively k -1 iteration to obtain the primary reactance and fault distance, X m , X n The adjusted m Section n The starting reactance value of the segment, L m For the setting m The starting distance of the segment, L m+1 For the setting m Segment end distance, L n For the setting n The starting distance of the segment, L n+1 For the setting n Segment end distance, x m is the unit mutual reactance between lines.

2. The method for direct fault location measurement of double-track electrified railway according to claim 1, characterized in that: In step 2, when the feeder circuit breaker is in the closed position, the line feeder protection device to which the circuit breaker belongs determines whether a fault occurs in the line feeder based on the bus voltage and the line feeder current, based on distance protection and current quick-break protection.

3. The method for direct fault location measurement of double-track electrified railway according to claim 1, characterized in that: In step 2, the current increment flag sent by another feeder protection device includes: When another feeder protection device determines that the current increment of the feeder current exceeds a preset threshold, the current increment flag is set to 1, and the device is connected to the feeder protection device of the same line through the device outlet, or a goose message is sent through the network interface and the feeder protection device of the same line subscribes to goose; The conditions for setting the current increment flag are as follows: △ I 2≥ Ith △I2=I2h—I2q Among them, △ I 2 is the increment of the effective value of the two adjacent cycles of current of another feeder at the time of fault. Ith is the increment threshold, I 2 h is the effective value of the current of the latter cycle among two adjacent cycles of another feeder line, I 2 q It is the effective value of the current in the previous cycle.

4. The method for direct fault location measurement of double-track electrified railway according to claim 1, characterized in that: The step 2 of determining the traction power supply operation mode at the time of the fault includes: When the feeder protection device of this line detects a line fault and the current increment flag issued by the feeder protection device of another line is set, it is judged to be in parallel operation mode; when the feeder protection device of this line detects a line fault, but the current increment flag issued by the feeder protection device of another line is not set, it is judged to be in de-parallel operation mode.

5. A double-track electrified railway direct fault distance measurement system based on the distance measurement method according to any one of claims 1 to 4, characterized in that: include: Sampling module, used to collect bus voltage of traction substation and current signals of feeder of the same line in real time; The fault and operation mode identification module is used to determine the fault type according to the bus voltage, feeder circuit breaker position signal and feeder current, and to determine the traction power supply operation mode in combination with the current increment sign issued by the feeder protection device of another type; The fault distance calculation module calculates the fault distance according to the traction power supply operation mode, that is, when the uplink and downlink feeders are separated, the fault distance is calculated according to the piecewise linear reactance method, and when the uplink and downlink feeders are parallel, the fault distance is calculated according to the modified reactance method.

6. The double-track electrified railway direct supply fault distance measurement system according to claim 5, characterized in that: The fault and operation mode identification module includes a fault identification submodule and an operation mode identification submodule; The fault determination submodule determines whether a fault occurs in the feeder of the same line based on distance protection and current quick-break protection; The operation mode determination submodule receives the current increment flag issued by another row feeder protection device. When the row feeder protection device detects that a line fault has occurred and the current increment flag issued by another row feeder protection device is set, it is determined to be in parallel operation mode. When the row feeder protection device detects that a line fault has occurred, but the current increment flag issued by another row feeder protection device is not set, it is determined to be in de-parallel operation mode.

7. The double-track electrified railway direct supply fault distance measurement system according to claim 5 or 6, characterized in that: The fault distance calculation module includes a piecewise linear reactance method distance measurement submodule and a modified reactance method distance measurement submodule; The piecewise linear reactance distance measurement submodule calculates the fault distance according to the piecewise linear reactance method, and calculates the measured reactance value according to the bus voltage and feeder current. When the measured reactance value is within the reactance range of a certain segment, the fault distance is calculated according to the segment reactance and segment kilometers set by the feeder protection device; The corrected reactance distance measurement module calculates the fault distance by the corrected reactance method. The measured reactance value is calculated according to the bus voltage at the time of the fault and the feeder current of the fault line, and the piecewise linear reactance fault distance is calculated. The reactance component caused by the mutual inductance is calculated based on the distance, and the influence of this component is removed through repeated iterations, thereby realizing the correction of the fault distance and obtaining an accurate fault distance.

8. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform any one of the methods according to claims 1 to 4.

9. A computer device, characterized in that: include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the methods according to claims 1 to 4.

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