Fault calibration method of direct power supply mode with return wire and related equipment

Abstract

The invention discloses a fault calibration method and related equipment for a direct power supply mode with a return wire, and the method comprises the steps: constructing a loop system composed of a transmission conductor and a return conductor in a traction network, and determining the long loop unit impedance of the traction network through analyzing the electrical parameters in the loop system; taking a traction network substation as a power supply end, and determining the relationship between the first fault impedance and the first distance when the contact network has a fault; determining the relationship between the second fault impedance and the third distance when the contact network fault occurs by taking the subarea as a power supply end; determining the first fault impedance value based on the actual electrical parameter value of the substation; determining a second fault impedance value based on the actual electrical parameter value of the section post; when the difference value between the first distance and the third distance is smaller than a preset threshold value, it is judged that the overhead line system breaks down, and the fault point is located at the position away from the substation side electric connection point by the first distance. A power substation and a subarea station are used as the power supply side, the fault of the overhead line system is analyzed, and the fault point is accurately positioned.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrified railway traction power supply technology, in particular to a fault calibration method of a direct power supply mode with a return line and related equipment. BACKGROUND

[0002] With the continuous advancement of electrified railway construction, a batch of mountainous electrified railways with a maximum speed of 200km / h passenger and freight mixed line double-track railway as a representative have begun to be constructed. Such railways often have complex geological conditions and need to pass through more bridges and tunnels. Due to the difficult tunnel engineering and small tunnel section, the direct power supply mode with a return line of a relatively simple structure is adopted for the maximum speed of 200km / h passenger and freight mixed line double-track railway.

[0003] The direct power supply mode with a return line usually refers to that the traction power output by the traction substation is directly transmitted to the electric locomotive (or motor train unit) through the catenary, and after the locomotive consumes power, the current does not simply rely on the return of the steel rail, but mainly flows back to the traction substation through the specially erected return line, forming a complete power supply loop. At the same time, in order to improve the power supply capacity, a reinforcing line is added. Since the reinforcing line and the catenary are equipotential conductors, the overhead layout in the tunnel can be realized.

[0004] The addition of the reinforcing line will make the impedance of the traction network present a nonlinear distribution with the position change of the connection point between the reinforcing line and the catenary, resulting in that the fault calibration characterized by linear impedance distribution cannot effectively determine whether the ground fault is caused by the catenary (catenary or load-bearing cable) or the reinforcing line, and it is difficult to accurately locate the fault position. SUMMARY

[0005] The present application aims to provide a fault calibration method of a direct power supply mode with a return line and related equipment, which analyzes the fault of the catenary (or reinforcing line) based on the relationship between the fault impedance and the distance and the actual fault impedance, respectively, with the substation and the substation as the power supply side, to accurately locate the fault point, thereby solving the problem of inaccurate fault positioning of the direct power supply mode with the reinforcing line.

[0006] The present application is implemented by the following technical solutions:

[0007] The first aspect of the present application provides a fault calibration method of a direct power supply mode with a return line, comprising:

[0008] A loop system composed of transmission conductors and return conductors in the traction network is constructed, and the unit impedance of the long loop of the traction network is determined by analyzing the electrical parameters in the loop system;

[0009] The traction network substation is taken as a power supply end, and based on the long loop unit impedance, a relationship between a first fault impedance and a first distance is determined when the overhead line system fails; the first distance represents a distance between a first preset fault point and an electrical connection point on the substation side;

[0010] The substation is taken as a power supply end, and based on the long loop unit impedance, a relationship between a second fault impedance and a third distance is determined when the overhead line system fails; the third distance represents a distance between a third preset fault point and an electrical connection point on the substation side;

[0011] Based on actual electrical parameter values of the substation, the first fault impedance value is determined; and based on actual electrical parameter values of the substation, the second fault impedance value is determined;

[0012] When a difference between the first distance and the third distance is less than a preset threshold, it is determined that the overhead line system fails, and a fault point is located at the first distance from the electrical connection point on the substation side;

[0013] The first fault impedance represents an equivalent impedance of a fault occurring segment when the substation is a power supply; and the second fault impedance represents an equivalent impedance of a fault occurring segment when the substation is a power supply.

[0014] In a feasible implementation manner, the method further includes:

[0015] The traction network substation is taken as a power supply end, and based on the long loop unit impedance, a relationship between a first fault impedance and a second distance is determined when the reinforced wire fails; the second distance represents a distance between a second preset fault point and an electrical connection point on the substation side;

[0016] The substation is taken as a power supply end, and based on the long loop unit impedance, a relationship between a second fault impedance and a fourth distance is determined when the reinforced wire fails; the fourth distance represents a distance between a fourth preset fault point and an electrical connection point on the substation side;

[0017] Based on actual electrical parameter values of the substation, the first fault impedance value is determined; and based on actual electrical parameter values of the substation, the second fault impedance value is determined;

[0018] When a difference between the second distance and the fourth distance is less than a preset threshold, it is determined that the reinforced wire fails, and a fault point is located at the second distance from the electrical connection point on the substation side.

[0019] In a feasible implementation manner, the method further includes: the transmission conductor includes a contact line, a catenary, and a reinforced wire; and the return flow conductor includes a rail 1, a rail 2, a return flow line, a through ground wire, and the ground.

[0020] In a feasible implementation, the loop system composed of the transmission conductor and the return conductor in the traction network is constructed, and the long-loop equivalent impedance of the traction network is determined by analyzing the electrical parameters in the loop system, and specifically includes:

[0021] Each transmission conductor in the traction network forms a loop with each loop conductor, and the loops constitute a loop system; wherein, any transmission conductor and any return conductor constitute a loop;

[0022] Based on the current characteristics in each loop, the self-inductance coefficients of each loop in the loop system and the mutual inductance coefficients between different loops are calculated;

[0023] Based on the self-inductance coefficients and mutual inductance coefficients, the unit length inductance matrix of each loop is determined;

[0024] Based on the characteristics of each loop itself and the characteristics of the shared conductors between different loops, the unit length resistance matrix of each loop is determined;

[0025] Based on the unit length inductance matrix of each loop and the unit length resistance matrix of each loop, the unit length impedance matrix of each loop is determined;

[0026] Based on the unit length impedance matrix of each loop and the electrical parameters in the traction network, the long-loop equivalent impedance of the traction network is determined.

[0027] In a feasible implementation, the first fault impedance is the parallel impedance of the first spatial loop impedance and the second spatial loop impedance;

[0028] The first space is a space composed of a line between a short-circuit fault point on the catenary and a power substation side electrical connection point, a line connecting the power substation side electrical connection point to the catenary and the reinforcing wire respectively, a line between the reinforcing wire and the power substation side electrical connection point, and a perpendicular line from the short-circuit fault point to the reinforcing wire; the second space is a space composed of a line between a short-circuit fault point on the catenary and a substation side electrical connection point, a line connecting the substation side electrical connection point to the catenary and the reinforcing wire respectively, a line between the reinforcing wire and the substation side electrical connection point, and a perpendicular line from the short-circuit fault point to the reinforcing wire.

[0029] The first spatial loop is a loop formed by the traction substation side catenary electrical connection point and the short-circuit fault point, and the second spatial loop is a loop formed by the traction substation side reinforcing wire electrical connection point through the substation side electrical connection point to the short-circuit fault point.

[0030] In a feasible implementation, the determination of the second spatial loop impedance specifically includes:

[0031] Based on the flux linkage generated by each loop in the loop system in the second space, the spatial magnetic field matrix of the second space is determined;

[0032] Deriving the spatial magnetic field matrix with respect to time, and determining a voltage variation matrix of the second space based on voltage drop characteristics of each loop;

[0033] Transforming the voltage variation matrix based on the relationship between the current of each loop of the catenary and the current of each loop of the reinforcing wire, to determine the current of each loop, and the current of each conductor and the current distribution ratio in the loop;

[0034] Determining the loop impedance of the second space based on the current of each conductor and the current distribution ratio.

[0035] In an implementable manner, the determination of the loop impedance of the first space specifically comprises:

[0036] Determining a spatial magnetic field matrix of the first space based on the flux linkage generated by each loop in the loop system in the first space;

[0037] Deriving the spatial magnetic field matrix with respect to time, and determining a voltage variation matrix of the first space based on voltage drop characteristics of each loop;

[0038] Transforming the voltage variation matrix based on the relationship between the current of each loop of the catenary and the current of each loop of the reinforcing wire, and adjusting the current proportion of the catenary and the current proportion of the reinforcing wire by moving the position of the short-circuit fault point on the catenary, to determine the current of each loop, and the current of each conductor and the current distribution ratio in the loop, when the voltage drop of the loop in the first space is equal to the voltage drop of the loop in the second space;

[0039] Determining the loop impedance of the first space based on the current of each conductor and the current distribution ratio.

[0040] The second aspect of the present application provides a fault calibration device in a direct power supply mode with a return wire, comprising:

[0041] A long loop unit impedance calculation unit is configured to construct a loop system composed of transmission conductors and return conductors in a traction network, and determine the unit impedance of the long loop in the traction network by analyzing electrical parameters in the loop system;

[0042] A first relationship determination unit is configured to determine the relationship between a first fault impedance and a first distance when a fault occurs in the catenary based on the unit impedance of the long loop, with the traction substation as a power supply end; the first distance represents the distance between a first preset fault point and an electrical connection point on the side of the substation;

[0043] A second relationship determination unit is configured to determine the relationship between a second fault impedance and a third distance when a fault occurs in the catenary based on the unit impedance of the long loop, with the substation as a power supply end; the third distance represents the distance between a third preset fault point and an electrical connection point on the side of the substation;

[0044] a fault impedance calculation unit, configured to determine the first fault impedance value based on actual electrical parameter values of the substation, and determine the second fault impedance value based on actual electrical parameter values of the subarea;

[0045] a fault calibration unit, configured to determine that the overhead contact line is faulty and the fault point is located at a first distance from the electrical connection point on the substation side when a difference between the first distance and the third distance is less than a preset threshold value.

[0046] The first fault impedance represents an equivalent impedance of a segment where the fault occurs when the substation is the power supply, and the second fault impedance represents an equivalent impedance of a segment where the fault occurs when the subarea is the power supply.

[0047] The third aspect of the present application provides an electronic device, comprising a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions are executed by the processor to implement the steps of the above method.

[0048] The fourth aspect of the present application provides a storage medium, comprising a program or instructions stored in the storage medium, wherein the program or instructions are executed by a processor to implement the steps of the above method.

[0049] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0050] The embodiments of the present application analyze the overhead contact line (or reinforced line) fault by taking the substation and the subarea as the power supply side respectively, determine the relationship between the fault impedance and the fault point position (the first distance) when the overhead contact line is faulty and the substation is the power supply end, and the relationship between the fault impedance and the fault point position (the second distance) when the overhead contact line is faulty and the subarea is the power supply end, determine the actual fault impedance based on the actual electrical parameters in the power grid, obtain the values of the first distance and the second distance based on the above determined relationships, and if the values of the two distances are (approximately) equal (i.e. the difference between the two values is less than a preset threshold value), it is determined that the overhead contact line indeed has a fault point, and the fault point is located at the position corresponding to the first distance obtained above, thereby realizing accurate positioning of the fault point. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the example embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0052] Figure 1 A flowchart of a fault calibration method with a backflow line direct power supply mode provided by the embodiments of the present application;

[0053] Figure 2 A schematic diagram of a traction net transmission and return conductor provided by the embodiment of the present application with the added reinforcing wire and return wire direct power supply mode;

[0054] Figure 3 A schematic diagram of a traction substation as a power end contact net fault provided by the embodiment of the present application;

[0055] Figure 4 A local enlarged schematic diagram of a traction substation as a power end contact net fault provided by the embodiment of the present application;

[0056] Figure 5 A schematic diagram of a traction substation as a power end reinforcing wire fault provided by the embodiment of the present application;

[0057] Figure 6 A schematic diagram of a substation as a power end contact net fault provided by the embodiment of the present application;

[0058] Figure 7 A schematic diagram of a substation as a power end reinforcing wire fault provided by the embodiment of the present application;

[0059] Figure 8 A comprehensive equivalent impedance diagram of a traction substation and substation as a power, contact net and reinforcing wire fault provided by the embodiment of the present application;

[0060] Figure 9 A flowchart of an implementation of a fault calibration method of a direct power supply mode with return wire provided by the embodiment of the present application;

[0061] Figure 10 A schematic diagram of the arrangement of each conductor in a tunnel in a direct power supply mode with return wire provided by the embodiment of the present application in one example;

[0062] Figure 11 An equivalent impedance diagram of a traction substation as a power end, contact net fault, first space contact net and reinforcing wire loop provided by the embodiment of the present application in one example;

[0063] Figure 12 A comprehensive equivalent impedance diagram of a traction substation as a power end, contact net fault in a section and reinforcing wire loop at different positions provided by the embodiment of the present application in one example;

[0064] Figure 13 An equivalent impedance diagram of a traction substation as a power end, reinforcing wire fault, first space contact net and reinforcing wire loop provided by the embodiment of the present application in one example;

[0065] Figure 14An example provided by the embodiment of the present application is that the traction substation is the power supply end, and the comprehensive equivalent impedance diagram of the reinforced wire fault occurring at different positions in the section loop is provided;

[0066] Figure 15 An example provided by the embodiment of the present application is that the traction substation is the power supply end, and the comprehensive equivalent impedance diagram of the reinforced wire fault occurring at different positions in the section loop is provided;

[0067] Figure 16 A specific schematic diagram of fault calibration in an example provided by the embodiment of the present application is provided.

[0068] Figure 17 A structural schematic diagram of a fault calibration device in a direct power supply mode with a return line provided by the embodiment of the present application is provided.

[0069] Figure 18 A structural schematic diagram of a computing device provided by the embodiment of the present application is provided. DETAILED DESCRIPTION

[0070] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with embodiments and drawings, and the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0071] Those skilled in the art can know that, with the development of technology and the appearance of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0072] The terms “include” and “have” and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion, so that the processes, methods, systems, products or devices containing a series of units do not have to be limited to those units, but can include other units that are not clearly listed or inherent to these processes, methods, products or devices.

[0073] Embodiment One

[0074] The embodiment one of the present application provides a fault calibration method in a direct power supply mode with a return line, to solve the problem of inaccurate fault positioning of the direct power supply mode with added reinforced wires.

[0075] The execution subject of the method can be any computing device that can realize the method, such as a server, a mobile phone, a personal computer, a smart wearable device, a smart robot, etc.

[0076] In addition, the execution order of different steps is not limited in the embodiments of the present application. When the method provided by the embodiments of the present application is used, the execution order of different steps can be adjusted according to actual needs.

[0077] To clearly introduce the scheme, the following is first explained:

[0078] When the direct power supply mode with a return line is adopted in the embodiments of the present application, in order to realize current balance, guarantee the effect of reducing the impedance of the traction network and improving the current carrying capacity of the reinforcing wire, the reinforcing wire and the overhead contact line (contact wire and messenger wire) are usually separated by a certain distance and are electrically connected. In this way, several sections are formed in the power supply arm. When the load is located in a section, the current distribution between the section and the traction substation and the overhead contact line in other sections and the reinforcing wire is constant, the unit length impedance is a constant value, which is similar to the AT (autotransformer feeding system) power supply mode. We can define it as long loop impedance. For the section where the load is located, the current distribution is different with the change of the load position, the unit length impedance is a variable of the position parameter. Similarly, referring to the AT power supply mode, we also define it as segment loop impedance.

[0079] The addition of the reinforcing wire will make the impedance of the traction network present a nonlinear distribution with the change of the connection point position between the reinforcing wire and the overhead contact line, resulting in inaccurate fault calibration characterized by linear impedance distribution, which cannot effectively determine whether the overhead contact line (contact wire or messenger wire) or the reinforcing wire is grounded, and the fault position cannot be accurately calibrated. In the past, the reinforcing wire and the overhead contact line are connected every 500-800 m, and the influence range of inaccurate fault calibration is small. However, for the connection of the reinforcing wire, the railway operation part proposes to: as far as possible, lengthen the connection distance, reduce the connection times, and reduce the maintenance operation points. However, the increase of the connection distance will result in the expansion of the influence range of inaccurate fault calibration when the traction network is short-circuited, which cannot meet the needs of on-site fault finding. Therefore, in combination with the problem, the embodiments of the present application carry out impedance calculation and analysis of the traction network in this application scenario based on the precise calculation method of the traction network impedance, and a new fault calibration method is proposed.

[0080] The method adopts the precise calculation theory of the traction network impedance, and the results obtained by analyzing and calculating the faults of the reinforcing wire and the overhead contact line based on the traction substation and the substation as the power supply side, takes the traction network impedance as the basic criterion, and takes the unique correspondence between the fault type and position and the impedance criterion as the target, to realize the accuracy of fault calibration.

[0081] To facilitate description, the fault calibration equipment of a direct power supply mode with a return line is taken as an example of the execution subject of the method, and the method provided by the embodiments of the present application is introduced in detail.

[0082] AsFigure 1 Fig. 1 is a flow chart illustrating a specific implementation of a fault calibration method for a direct power supply mode with a return line according to an embodiment of the present application, including the following steps 11-15:

[0083] Step 11: Construct a loop system composed of transmission conductors and return conductors in the traction network, and determine the long loop unit impedance of the traction network by analyzing electrical parameters in the loop system.

[0084] The electrical parameters include current, inductance, resistance, voltage, and the like.

[0085] The specific implementation of step 11 includes the following steps 1101-1106:

[0086] Step 1101: Each transmission conductor in the traction network forms a loop with each loop conductor, constituting a loop system; wherein any transmission conductor and any return conductor constitute a loop.

[0087] The conductors in the traction network of the direct power supply mode with a return line with an added reinforcing line are classified into transmission conductors and return conductors, wherein the contact line, the load-bearing cable, and the reinforcing line are transmission conductors, and the rail 1, the rail 2, the return line, the through ground wire, and the ground are return conductors. That is, the system is converted into a multi-transmission conductor and multi-return conductor loop system composed of 3 transmission conductors and 5 return conductors.

[0088] Table 1

[0089] As shown in Table 1 above, Table 1 is a loop composition table for the traction network with a return line and a direct power supply mode with an added reinforcing line. Among them, the transmission conductor contact line and the return conductor (rail 1, rail 2, return line, through ground wire, and ground) form loop 1-loop 5 respectively; the transmission conductor load-bearing cable and the return conductor (rail 1, rail 2, return line, through ground wire, and ground) form loop 6-loop 10 respectively; the transmission conductor reinforcing line and the return conductor (rail 1, rail 2, return line, through ground wire, and ground) form loop 11-loop 15 respectively. Loop 1-loop 15 constitute a loop system.

[0090] As Figure 2As shown, the distance between two conductors in each of the circuits 1-4, 6-9, 11-14 corresponds to d1-d4, d6-d9, d11-d14. The radii of the contact wire, the messenger wire, the strength wire, the rail 1, the rail 2, the return wire and the through ground wire are r1-r7 respectively. The distances between the messenger wire and the contact wire, the messenger wire and the strength wire, the contact wire and the strength wire, the rail 1 and the rail 2, the rail 1 and the return wire, the rail 1 and the through ground wire, the rail 2 and the return wire, the rail 2 and the through ground wire, and the return wire and the through ground wire correspond to l12, l23, l13, l45, l46, l47, l56, l57 and l67 respectively.

[0091] Step 1102: Based on the current characteristics in each circuit, the self-inductance coefficients of each circuit in the circuit system and the mutual inductance coefficients between different circuits are calculated respectively.

[0092] Calculation of the self-inductance coefficient of each circuit: the self-inductance coefficient l ii of circuit i is calculated. Taking circuit 1 as an example to illustrate the self-inductance coefficient of a non-ground return circuit, assuming that the circuit current in circuit 1 is I1, then the current in the contact wire is I1 and the current in the rail 1 is -I1, which together form a basic space magnetic field unit. According to the magnetic linkage calculation formula between two conductors, l 11 is obtained as follows:

[0093] (1)

[0094] where μ is the magnetic permeability. Similarly, the self-inductance coefficients l ii of circuits 2-4, 6-9 and 11-14 are obtained as follows: (i=1, 2, 3, 4, 6, 7, 8, 9,11,12,13,14).

[0095] Taking circuit 5 as an example to illustrate the self-inductance coefficient of a ground return circuit. Assuming that the self-inductance coefficient l of circuit 5 is:

[0096] (2)

[0097] where h is the equivalent depth of the earth, ρ is the earth resistivity (Ω·m), and f is the frequency. Similarly, the self-inductance coefficients l and l of circuits 10 and 15 are obtained as follows: .

[0098] Calculation of the mutual inductance coefficient between circuits: the mutual inductance coefficient l ij between circuit i and circuit j is calculated as follows: ji Taking circuits 1 and 7 as an example to illustrate the mutual inductance coefficient l 17The magnetic flux generated by the current I1 of the loop 1 in the loop 7 through the contact line The magnetic flux generated by the current I1 of the loop 1 in the loop 7 through the steel rail 1 The comprehensive magnetic flux generated by the loop 1 in the loop 7 The magnetic flux and the current can be further obtained as l 17 :

[0099] (3)

[0100] In the formula, d1 and d7 are the distances between the corresponding two conductors of the loop 1 and the loop 7 respectively, and l12 and l45 are the distances between the contact line and the steel rail 1 and between the steel rail 1 and the steel rail 2 respectively.

[0101] The mutual inductance coefficient l ij The mutual inductance coefficient l 15 The magnetic flux generated by the current I1 of the loop 1 in the loop 5 through the contact line The magnetic flux generated by the current I1 of the loop 1 in the loop 5 through the steel rail 1 The comprehensive magnetic flux generated by the loop 1 in the loop 5 The magnetic flux and the current can be further obtained as l 15 :

[0102] (4)

[0103] The mutual inductance coefficient l ij The mutual inductance coefficient l 510 The magnetic flux generated by the current I1 of the loop 5 in the loop 10 through the contact line The magnetic flux generated by the current I1 of the loop 5 in the loop 10 through the steel rail 1 The comprehensive magnetic flux generated by the loop 1 in the loop 10 The magnetic flux and the current can be further obtained as l 510 :

[0104] (5)

[0105] Step 1103: Based on the self-inductance coefficient and the mutual inductance coefficient, determine the inductance matrix of each loop per unit length.

[0106] Based on the self-inductance coefficient and the mutual inductance coefficient calculated in step 1102, the inductance matrix of each loop per unit length of the traction network in the direct power supply mode with the added reinforced line and the return line can be obtained, wherein, is the self-inductance coefficient of the loop i, is the mutual inductance coefficient between loop i and loop j, = Then we have:

[0107] (6)

[0108] Step 1104: determining the unit length resistance matrix of each loop based on the characteristics of each loop itself and the characteristics of the shared conductors between different loops.

[0109] Suppose the unit length resistances of the contact line, the catenary, the reinforcing wire, the rail 1, the rail 2, the return line, the through ground wire and the ground are R1, R2, …, R8, and the comprehensive resistance of the traction network is R, the following three cases are considered:

[0110] 1) Self-resistance in each loop: the self-resistance in each loop is the sum of the resistances of the transmission conductor and the return conductor constituting the loop, that is, the value at the diagonal position in the comprehensive resistance matrix R of the traction network is the sum of the resistances of the two conductors in the loop.

[0111] 2) Mutual resistance between loops with shared transmission conductors or shared return conductors: according to the relationship between loop current and voltage drop, the mutual resistance between loops with shared transmission conductors or shared return conductors is equal to the resistance value of the shared conductor.

[0112] 3) Mutual resistance between independent two loops (i.e. loops that are neither shared transmission conductors nor shared return conductors): the mutual resistance between independent two loops is 0.

[0113] Therefore, the comprehensive resistance R (symmetric matrix) of the traction network can be represented as:

[0114] (7)

[0115] In the formula, represents a 5-dimensional matrix with all elements being 1, represents a diagonal matrix.

[0116] Step 1105: determining the unit length impedance matrix of each loop based on the unit length inductance matrix of each loop and the unit length resistance matrix of each loop.

[0117] From formula (6) and formula (7), the unit length impedance matrix of each loop is:

[0118] (8)

[0119] Step 1106: determining the equivalent impedance of the long loop of the traction network based on the unit length impedance matrix of each loop and the electrical parameters in the traction network.

[0120] Suppose ΔU1, ΔU2, …, ΔU 15Voltage drop of loop 1 to loop 15 respectively; I1, I2, …, I 15 Currents through loop 1 to loop 15 respectively. Since the 15 loops are in parallel, assuming I0 is the total current of all transmission conductors (or all return conductors), then there are ΔU1= ΔU2= …= ΔU 15 = ΔU, I1+ I2+ …+ I 15 = I0. Assuming k1, k2, …, k 15 are the current distribution coefficients of the 15 loops, then there are I1= k1I0, I2= k2I0, …, I 15 = k 15 I0. According to the relationship between the voltage drop of each loop and the magnetic flux linkage of the loop, the relationship between the voltage drop, inductance and current of each loop can be obtained as follows:

[0121] (9)

[0122] The equivalent unit length comprehensive equivalent impedance Z corresponding to the system can be obtained as:

[0123] (10)

[0124] The impedance value is the equivalent impedance of the long loop.

[0125] Step 12: Taking the traction network substation as the power supply end, based on the unit impedance of the long loop, determining the relationship between the first fault impedance and the first distance when the catenary fails; the first distance represents the distance between the first preset fault point and the electrical connection point on the substation side.

[0126] Among them, for the segment loop impedance, the impedance presented from different power supply ends is different. Taking the traction substation as the power supply end, when the fault point is located in the catenary, the first fault impedance can be considered as the parallel impedance of the first spatial loop impedance and the second spatial loop impedance.

[0127] In order to accurately calculate the segment impedance value in this case, it is necessary to analyze the spatial magnetic field in the segment. Since the current is the source of the magnetic field, in order to accurately analyze the magnetic field, the first thing is to accurately obtain the current distribution, that is, the current distribution ratio in each conductor.

[0128] As Figure 3 , Figure 4 shown, the current distribution in the segment can be divided into two spaces, namely the first space and the second space.

[0129] The first space is a space composed of a line between a short-circuit fault point on the catenary and a power substation side electrical connection point, a line in which the power substation side electrical connection point is connected to the catenary and the reinforcing wire respectively, a line between the reinforcing wire and the power substation side electrical connection point, and a vertical line from the short-circuit fault point to the reinforcing wire; in the space, the current ratio of the catenary current to the reinforcing wire current changes constantly with different short-circuit fault point positions.

[0130] The second space is a space composed of a line between a short-circuit fault point on the catenary and a power substation side electrical connection point, a line in which the power substation side electrical connection point is connected to the catenary and the reinforcing wire respectively, a line between the reinforcing wire and the power substation side electrical connection point, and a vertical line from the short-circuit fault point to the reinforcing wire; in the space, the current ratio of the catenary current to the reinforcing wire current changes constantly with different short-circuit fault point positions.

[0131] The first space loop is a loop formed by the catenary electrical connection point on the traction power substation side and the short-circuit fault point, and the second space loop is a loop formed by the reinforcing wire electrical connection point on the traction power substation side, the power substation side electrical connection point, and the short-circuit fault point.

[0132] The determination of the second space loop impedance specifically includes the following steps 1201-1204:

[0133] Step 1201: determining a space magnetic field matrix of the second space based on the magnetic flux generated by each loop in the loop system in the second space.

[0134] The column-written space magnetic field matrix is:

[0135] (11)

[0136] In the formula, is the magnetic flux generated by the current in the loop 1 formed by the contact wire and the steel rail 1 in the second space, is the magnetic flux generated by the current in the loop 2 formed by the contact wire and the steel rail 2 in the second space, is the magnetic flux generated by the current in the loop 3 formed by the contact wire and the return wire in the second space, is the magnetic flux generated by the current in the loop 4 formed by the contact wire and the comprehensive ground wire in the second space, is the magnetic flux generated by the current in the loop 5 formed by the contact wire and the ground in the second space. Similarly, the magnetic flux generated by the current in the loops 6-10 and 11-15 composed of the bearing cable and the reinforcing wire as transmission conductors in the second space can be described, and finally a 15-dimensional symmetric matrix shown in formula (11) is formed to construct the magnetic field description matrix of the second space.

[0137] Step 1202: deriving the space magnetic field matrix with respect to time, and determining a voltage change matrix of the second space based on the voltage drop characteristics of each loop.

[0138] Rate of change of flux linkage with respect to time Formation of voltage variation matrix Therefore, the voltage variation matrix is obtained by taking the time derivative of the matrix with respect to time and the derivative factor with respect to the alternating current Considering that the loops of the contact wire, the messenger wire and the reinforcing wire are in parallel relationship, and the contact wire and the messenger wire in the loop are also in parallel relationship in the segment, the voltage drop of each loop of the contact wire and the messenger wire is equal, the voltage drop of each loop of the reinforcing wire is equal, and the voltage variation matrix is:

[0139] (12)

[0140] Step 1203: Based on the relationship between the current of each loop of the contact wire and the current of each loop of the reinforcing wire, the voltage variation matrix is transformed to determine the current of each loop, and the current of each conductor and the current distribution ratio in the loop.

[0141] In order to analyze the matrix, the elements of the 11th to 14th rows are subtracted from the element of the 15th row, and the 1st-10th loop currents and the element equal to the sum of the 11th-15th loop currents and opposite in direction are introduced, and the following equation can be obtained:

[0142] (13)

[0143] In order to analyze the current distribution, assuming that the voltage drop is unit "1", according to the matrix, the current of each loop can be obtained, and then the current of each conductor and the current distribution ratio can be obtained.

[0144] Step 1204: Based on the current of each conductor and the current distribution ratio, the second spatial loop impedance is determined.

[0145] Based on the current of each conductor and the current distribution ratio, and the formula in step 11, the second spatial loop impedance is determined.

[0146] The determination of the first spatial loop impedance specifically includes the following steps 1211-1214:

[0147] Step 1211: Based on the flux linkage generated by each loop in the loop system in the first space, the spatial magnetic field matrix of the first space is determined.

[0148] In this step, the spatial magnetic field matrix of the first space is the same as the spatial magnetic field matrix of the second space.

[0149] Step 1212: Taking the time derivative of the spatial magnetic field matrix, and based on the voltage drop characteristics of each loop, the voltage variation matrix of the first space is determined;

[0150] In this step, the voltage change matrix of the first space is the same as the voltage change matrix in step 1201.

[0151] Step 1213: Based on the relationship between the current in each circuit of the contact network and the current in each circuit of the reinforcing line, transform the voltage change matrix, and adjust the current ratio of the contact network and the current ratio of the reinforcing line by moving the position of the short-circuit fault point on the contact network. When the voltage drop of the first spatial circuit is equal to the voltage drop of the second spatial circuit, determine the current of each circuit, as well as the current of each conductor in the circuit and the current distribution ratio.

[0152] To analyze the voltage change matrix, the voltage drop matrix is ​​also transformed by subtracting the element of row 15 from the elements of rows 11 to 14. The relationship between the sum of currents in loops 1-10 and loops 11-15 is introduced. Since this ratio varies depending on the location of the short-circuit point, an iterative calculation method is introduced. The constraint is that the voltage drops calculated for the first and second loops are equal. Assuming the current ratio is k, the impedance of the first spatial loop is obtained. Based on the impedances of the first and second spatial loops, the current distribution, and the length, the voltage drops of the first and second spatial loops can be obtained. If the voltage drops calculated for the two loops are equal, the iteration ends; otherwise, the current ratio is adjusted until the two voltage drops are equal.

[0153] To facilitate iteration, we introduce Figure 4 The linear distribution of the contact current iT1 with position is used as the initial current distribution. Based on the long-loop current distribution calculation, when the short-circuit point is located at the electrical connection point in the direction of the substation, the proportion of the contact current iT1 is k1, and the proportion of the reinforcing wire current iT2 is 1-k1. As the short-circuit point moves towards the electrical connection point in the direction of the traction substation, the contact current gradually increases, and the reinforcing wire current gradually decreases. When the short-circuit point is located at the electrical connection point in the direction of the traction substation, the proportion of the contact current iT1 reaches 1. This process is assumed to be a linear distribution with distance, i.e., as... Figure 4 As the variable x (first distance) changes from 0 to D, the proportion of the contact wire current iT1 changes from 1 to k1. Therefore, the linear relationship between the proportion kj of the contact wire current iT1 and the distance x variable is: kj = k1 + (1-k1)*(Dx) / D. Similarly, the linear relationship between the proportion kg of the reinforcing conductor current iT2 and the distance x variable is: kg = (1-k1) - (1-k1)*(Dx) / D. This provides the initial value for the current constraint relationship. Iterative calculations based on this initial value can achieve convergence relatively quickly, thus obtaining the current in each conductor and its distribution ratio. It is evident that this current value includes the x variable, thus determining the relationship between the current and the first distance.

[0154] Step 1214: Determine the impedance of the first spatial loop based on the current in each conductor and the current distribution ratio.

[0155] The first space loop impedance can be obtained by using the impedance calculation formula in step 11. The segment loop impedance (first fault impedance) is in parallel connection with the first space loop impedance and the second space loop impedance when the traction substation is the power supply. According to the analysis and calculation results of the first space loop impedance and the second space loop impedance, since the first space loop impedance contains the relationship with the first distance, the comprehensive equivalent impedance of the overhead contact line fault occurring at different positions in the segment is obtained, that is, the relationship between the first fault impedance and the first distance when the overhead contact line fault occurs is determined.

[0156] Step 13: determining the relationship between the second fault impedance and the third distance when the overhead contact line fault occurs based on the long loop unit impedance and taking the substation as the power supply end; the third distance represents the distance between the third preset fault point and the electric connection point of the substation.

[0157] When the overhead contact line short circuit fault occurs, the segment loop impedance value is the parallel connection of the third loop impedance and the fourth loop impedance shown in the formula (3) in the description. Figure 5 The specific calculation method is the same as that of step 12, which will not be repeated here.

[0158] Step 14: determining the first fault impedance value based on the actual electrical parameter value of the substation; and determining the second fault impedance value based on the actual electrical parameter value of the substation;

[0159] The first fault impedance value is calculated based on the actual voltage and current values of the substation, and the second fault impedance value is calculated based on the actual voltage and current values of the substation. According to the relationship between the first fault impedance and the first distance in step 12 and the calculated first fault impedance value, the first distance value is obtained; according to the relationship between the second fault impedance and the third distance in step 13 and the calculated second fault impedance value, the third distance value is obtained.

[0160] Step 15: when the difference between the first distance and the third distance is less than a preset threshold, determining that the overhead contact line fault occurs and the fault point is located at the first distance from the electric connection point of the substation.

[0161] When the first distance value and the third distance value are approximately equal, that is, the difference is less than the preset threshold, it is considered that the fault points determined from the substation side and the substation side are the same, that is, it is determined that the overhead contact line fault occurs and the fault point is located at the first distance from the electric connection point of the substation.

[0162] The first fault impedance represents the equivalent impedance of the fault occurring segment when the substation is the power supply; the second fault impedance represents the equivalent impedance of the fault occurring segment when the substation is the power supply.

[0163] In one feasible implementation, following the same concept as the fault identification method for overhead contact line faults provided above, this embodiment also provides a fault identification method for reinforcing wire faults. This method includes the following steps S1 to S4:

[0164] Step S1: Taking the traction substation as the power supply end, based on the unit impedance of the long circuit, determine the relationship between the first fault impedance and the second distance when a reinforced line fault occurs; the second distance represents the distance between the second preset fault point and the electrical connection point on the substation side.

[0165] When the reinforcing wire fails, such as Figure 6 As shown, similarly, by referring to the calculation method of the equivalent impedance of the circuit in the faulty section of the overhead contact line, we can obtain... Figure 6 The equivalent impedances of the first and second space contact networks and the equivalent impedance of the reinforcing wire are used to obtain the first space loop impedance, the second space loop impedance, and the equivalent impedance of the parallel loop in the section. For the second space loop impedance, since its current distribution is the same as when the contact network fails, its impedance value is equal. However, for the first space impedance, the impedance value is different. Similarly to steps 1213-1214 above, since the first space loop impedance includes the relationship with the second distance, the comprehensive equivalent impedance for contact network faults occurring at different locations in the section loop is obtained, thus determining the relationship between the first fault impedance and the second distance when the reinforcing wire fails.

[0166] Step S2: Taking the substation as the power supply end, based on the unit impedance of the long loop, determine the relationship between the second fault impedance and the fourth distance when a reinforced line fault occurs; the fourth distance represents the distance between the fourth preset fault point and the electrical connection point on the substation side.

[0167] With the section as the power supply terminal, when a short-circuit fault occurs in the reinforced line, the loop impedance value in that section is... Figure 7 The parallel connection of the impedances of the third and fourth loops is shown.

[0168] Step S3: Determine the first fault impedance value based on the actual electrical parameter values ​​of the substation; and determine the second fault impedance value based on the actual electrical parameter values ​​of the section substation.

[0169] Based on the actual voltage and current values ​​of the substation, calculate the first fault impedance value; based on the actual voltage and current values ​​of the section substation, calculate the second fault impedance value. According to the relationship between the first fault impedance and the second distance in step S1, and the calculated first fault impedance value, obtain the second distance value; according to the relationship between the second fault impedance and the fourth distance in step S2, and the calculated second fault impedance value, obtain the fourth distance value.

[0170] Step S4: when the difference between the second distance and the fourth distance is less than a preset threshold, it is determined that the reinforcing wire is faulty, and the fault point is located at the second distance from the electric connection point on the side of the substation.

[0171] When the second distance value and the fourth distance value are approximately equal, i.e., the difference is less than a preset threshold, it is considered that the fault points determined from the side of the substation and the side of the substation are the same, i.e., it is determined that the overhead contact line is faulty, and the fault point is located at the second distance from the electric connection point on the side of the substation.

[0172] As shown in Figure 8 , a comprehensive equivalent impedance diagram of the overhead contact line and the reinforcing wire fault is given, with the traction substation and the substation as power sources.

[0173] For the direct power supply mode with the added reinforcing wire and the return wire, the traditional traction substation fault distance measurement is adopted. For the same impedance value, the corresponding positions of the overhead contact line fault and the reinforcing wire fault are different, and therefore, the fault type cannot be accurately determined as the overhead contact line fault or the reinforcing wire fault. In combination with the above impedance calculation and analysis, the substation fault distance measurement is introduced, and the results are compared with the traction substation fault distance measurement results. In this way, the fault type can be accurately distinguished as the overhead contact line fault or the reinforcing wire fault.

[0174] The embodiments of the present application analyze the overhead contact line (or reinforcing wire) fault by taking the substation and the substation as the power source side, respectively, determine the relationship between the fault impedance and the fault point position (first distance) when the overhead contact line is faulty, and the relationship between the fault impedance and the fault point position (second distance) when the substation is the power source side. Based on the actual electrical parameters in the power grid, the actual fault impedance is determined, the values of the first distance and the second distance are obtained based on the above determined relationship, and if the values of the two distances are (approximately) equal (i.e., the difference between the two is less than a preset threshold), it is indicated that the overhead contact line indeed has a fault point, and the fault point is located at the position corresponding to the first distance obtained above, i.e., the accurate positioning of the fault point is achieved.

[0175] In a specific implementation manner, as shown in Figure 9 , the following steps 901 to step 916 are included:

[0176] Step 901: calculate the unit impedance of the traction network long loop;

[0177] Step 902: taking the traction substation as the power source, calculate the equivalent impedance in the overhead contact line fault section;

[0178] Step 903: taking the traction substation as the power source, calculate the equivalent impedance in the reinforcing wire fault section;

[0179] Step 904: Based on the calculation results of steps 901-903, the relationship between fault impedance and distance of the catenary and the strengthening line powered by the traction substation is determined respectively;

[0180] Step 905: The loop equivalent impedance in the catenary fault section is calculated when the substation is powered;

[0181] Step 906: The loop equivalent impedance in the strengthening line fault section is calculated when the substation is powered;

[0182] Step 907: Based on the calculation results of steps 901, 905, and 906, the relationship between fault impedance and distance of the catenary and the strengthening line powered by the substation is determined;

[0183] Step 908: The impedance value Z1 corresponding to step 904 is calculated according to the voltage and current values of the substation, which includes the impedance Z1 corresponding to the catenary fault and the impedance Z1 corresponding to the strengthening line fault. It should be noted that the values of the impedance corresponding to the catenary fault and the impedance corresponding to the strengthening line fault may be different.

[0184] Step 909: According to the calculation results of steps 904 and 908, the fault distance L1 corresponding to Z1 when the catenary fails and the fault distance L2 corresponding to Z1 when the strengthening line fails are calculated;

[0185] Step 910: The impedance value Z1 corresponding to step 907 is calculated according to the voltage and current values of the substation, which includes the impedance Z2 corresponding to the catenary fault and the impedance Z2 corresponding to the strengthening line fault. It should be noted that the values of the impedance corresponding to the catenary fault and the impedance corresponding to the strengthening line fault may be different.

[0186] Step 911: According to the calculation results of steps 907 and 910, the fault distance L3 corresponding to Z2 when the catenary fails and the fault distance L4 corresponding to Z2 when the strengthening line fails are calculated;

[0187] Step 912: Determine whether L1 is approximately equal to L3; if yes, execute step 913; if no, execute step 914;

[0188] Step 913: The fault is a catenary fault, and the fault distance is L1; execute step 916;

[0189] Step 914: Determine whether L4 is approximately equal to L2; if yes, execute step 915; if no, end the process;

[0190] Step 915: The fault is a strengthening line fault, and the fault distance is L2;

[0191] Step 916: The fault distance measurement is completed.

[0192] To further verify the feasibility of the above method described in this embodiment, a specific example of fault location using the method of this embodiment is provided below.

[0193] The distribution of each conductor of the traction network in a certain electrified railway tunnel is shown in Figure 10 Figure 10 The contact wire, the messenger wire, the reinforcing wire, the return wire and the comprehensive ground wire are shown in the middle of Figure 11 The conductor parameters are shown in Table 2. The calculation results of the long circuit impedance of the traction network are shown in Table 3. The calculation results of the equivalent impedance of the second space circuit of the power supply, the fault section of the catenary are shown in Table 4. When the catenary fault occurs at different positions in the section circuit, the equivalent impedance of the first space catenary and the reinforcing wire circuit is shown in Figure 12 The equivalent impedance of the comprehensive catenary fault in the section circuit is shown in Figure 13 When the reinforcing wire fault occurs at different positions in the section circuit, the equivalent impedance of the first space catenary and the reinforcing wire circuit is shown in Figure 14 The equivalent impedance of the comprehensive reinforcing wire fault in the section circuit is shown in Figure 15 The equivalent impedance of the section circuit when the catenary or the reinforcing wire fault occurs at the substation is shown in

[0194] The main parameters and positions of each wire of the direct power supply traction network with reinforcing wire and return wire

[0195] Table 2

[0196] Note: 1. The track surface center is taken as the coordinate origin; 2. The earth is an important return path of the traction power supply system, and its letter code is E. The soil resistivity value is taken as 100 Ω.m in the calculation.

[0197] Calculation results of the circuit current distribution coefficient and the equivalent impedance per unit length

[0198] Table 3

[0199] Calculation results of the circuit current distribution coefficient and the equivalent impedance per unit length (catenary fault, calculation results of space 2)

[0200] Table 4

[0201] Note: ① The comprehensive impedance of the catenary circuit; ② The comprehensive impedance of the reinforcing wire circuit.

[0202] When the fault occurs in the middle of the power supply arm, the circuit impedance curves in the two intersection sections are as shown in Figure 16 ​As shown, the segment impedance measured by the traction substation feeder is 0.2336Ω, and it is noted that the segment loop impedance value is the measured impedance of the traction substation minus the long loop impedance value from the traction substation to the short-circuit point (not including the length of the segment loop) before the segment loop. Based on this, two fault calibration points can be obtained, one is the catenary fault occurring at 75% of the length of the segment loop, and the other is the reinforced wire fault occurring at 61% of the length of the segment loop, and the deviation of the two faults is 14% of the length of the segment loop. In order to accurately determine the fault nature and position, the segment loop impedance data measured by the substation is introduced, and the segment loop impedance value is also the measured impedance of the substation minus the long loop impedance value from the substation to the short-circuit point (not including the length of the segment loop) before the segment loop. If the fault occurs in the catenary, the segment impedance value measured by the substation is 0.08737Ω, and if the fault occurs in the reinforced wire, the segment impedance value measured by the substation is 0.1673Ω. Therefore, combined with the impedance measurement value of the substation, we can make an accurate and unique judgment on the fault type and fault position.

[0203] Embodiment Two

[0204] To solve the problem of inaccurate fault positioning of the direct power supply mode with added reinforced wire in the prior art, based on the same inventive concept as in Embodiment One, the present application embodiment also provides a fault device of a direct power supply mode with a return wire.

[0205] The specific structure diagram of the device is shown in Figure 17 As shown, the device comprises the following functional units 1701-1705:

[0206] The long loop unit impedance calculation unit 1701 is configured to construct a loop system composed of a transmission conductor and a return conductor in the traction network, and determine the long loop unit impedance of the traction network by analyzing electrical parameters in the loop system.

[0207] The transmission conductor comprises a contact wire, a load-bearing cable and a reinforced wire; and the return conductor comprises a rail 1, a rail 2, a return wire, a through ground wire and the ground.

[0208] The long loop unit impedance calculation unit is specifically configured to: form a loop system by each transmission conductor in the traction network corresponding to each loop conductor; any transmission conductor and any return current conductor form a loop; calculate self-inductance coefficients of each loop in the loop system and mutual inductance coefficients between different loops based on current characteristics in each loop; determine a loop unit length inductance matrix based on the self-inductance coefficients and the mutual inductance coefficients; determine a loop unit length resistance matrix based on characteristics of each loop and characteristics of a shared conductor between different loops; determine a loop unit length impedance matrix based on the loop unit length inductance matrix and the loop unit length resistance matrix; and determine a long loop equivalent impedance of the traction network based on the loop unit length impedance matrix and electrical parameters in the traction network.

[0209] The first relationship determination unit 1702 is configured to determine a relationship between a first fault impedance and a first distance when a catenary fault occurs based on the long loop unit impedance, with a traction network substation as a power supply end, and the first distance representing a distance between a first preset fault point and an electrical connection point of the substation.

[0210] The first fault impedance is a parallel impedance of a first spatial loop impedance and a second spatial loop impedance.

[0211] The first space is a space composed of a line between a short-circuit fault point on the catenary and the electrical connection point of the substation, a line connecting the catenary and the reinforcing wire at the electrical connection point of the substation, a line between the reinforcing wire and the electrical connection point of the substation, and a perpendicular line from the short-circuit fault point to the reinforcing wire, and the second space is a space composed of a line between a short-circuit fault point on the catenary and an electrical connection point of a substation, a line connecting the catenary and the reinforcing wire at the electrical connection point of the substation, a line between the reinforcing wire and the electrical connection point of the substation, and a perpendicular line from the short-circuit fault point to the reinforcing wire.

[0212] The first spatial loop is a loop formed by the electrical connection point of the traction substation and the short-circuit fault point, and the second spatial loop is a loop formed by the electrical connection point of the traction substation, the electrical connection point of the substation, and the short-circuit fault point.

[0213] The second relationship determination unit 1703 is configured to determine a relationship between a second fault impedance and a third distance when a catenary fault occurs based on the long loop unit impedance, with a substation as a power supply end, and the third distance representing a distance between a third preset fault point and an electrical connection point of the substation.

[0214] Determine a spatial magnetic field matrix of the second space based on magnetic fluxes generated by each loop in the loop system in the second space.

[0215] Deriving the spatial magnetic field matrix with respect to time, and determining a voltage variation matrix of the second space based on voltage drop characteristics of each loop;

[0216] Transforming the voltage variation matrix based on relationships between currents of each loop of the catenary and currents of each loop of the reinforcing wire, to determine currents of each loop, and conductor currents and current distribution ratios in the loops;

[0217] Determining loop impedances of the second space based on the conductor currents and the current distribution ratios.

[0218] The determination of the loop impedances of the first space specifically includes:

[0219] Determining a spatial magnetic field matrix of the first space based on magnetic fluxes generated by each loop in the loop system in the first space;

[0220] Deriving the spatial magnetic field matrix with respect to time, and determining a voltage variation matrix of the first space based on voltage drop characteristics of each loop;

[0221] Transforming the voltage variation matrix based on relationships between currents of each loop of the catenary and currents of each loop of the reinforcing wire, and adjusting current proportions of the catenary and current proportions of the reinforcing wire by moving a short-circuit fault point on the catenary, to determine currents of each loop, and conductor currents and current distribution ratios in the loops when voltage drops of the loops of the first space are equal to voltage drops of the loops of the second space.

[0222] Determining loop impedances of the first space based on the conductor currents and the current distribution ratios.

[0223] The fault impedance calculation unit 1704 determines the first fault impedance value based on actual electrical parameter values of the substation, and determines the second fault impedance value based on actual electrical parameter values of the partitioning substation;

[0224] The fault calibration unit 1705 determines that the catenary is faulty and the fault point is located at a first distance from the electrical connection point on the substation side when a difference between the first distance and the third distance is less than a preset threshold.

[0225] The first fault impedance represents an equivalent impedance of a fault occurring segment when the substation is a power supply; and the second fault impedance represents an equivalent impedance of a fault occurring segment when the partitioning substation is a power supply.

[0226] In a feasible implementation manner, the fault calibration device further includes:

[0227] Based on the long loop unit impedance, a relationship between the first fault impedance and a second distance is determined when a reinforcing wire fault occurs, with the traction network substation as a power supply end; the second distance represents a distance between a second preset fault point and an electrical connection point on the substation side.

[0228] The substation and the substation subarea are respectively taken as the power supply side, the relationship between the second fault impedance and the fourth distance when the reinforced line fault occurs is determined based on the long loop unit impedance, and the fourth distance represents the distance between the fourth preset fault point and the electric connection point of the substation side.

[0229] The first fault impedance value is determined based on the actual electrical parameter value of the substation, and the second fault impedance value is determined based on the actual electrical parameter value of the substation subarea.

[0230] When the difference between the second distance and the fourth distance is less than a preset threshold, it is determined that the reinforced line fault occurs and the fault point is located at the second distance from the electric connection point of the substation side.

[0231] The embodiments of the present application analyze the catenary (or reinforced line) fault by taking the substation and the substation subarea as the power supply side respectively, determine the relationship between the fault impedance and the fault point position (the first distance) when the catenary fault occurs by taking the substation as the power supply end, and the relationship between the fault impedance and the fault point position (the second distance) by taking the substation subarea as the power supply end. The actual fault impedance is determined based on the actual electrical parameter in the power grid, the values of the first distance and the second distance are obtained based on the above determined relationship, if the values of the two distances are (approximately) equal (i.e. the difference between the two is less than a preset threshold), it is indicated that the catenary indeed has a fault point, and the fault point is located at the position corresponding to the first distance obtained above, that is, the accurate positioning of the fault point is realized.

[0232] Based on the same inventive concept as the foregoing embodiments of the present application, the embodiments of the present application also provide a computing device.

[0233] As shown in Figure 18 The computing device includes a memory 1801 and a processor 1802. The memory 1801 can be configured to store various data to support operations on the electronic device. Examples of these data include instructions for any application or method operating on the electronic device. The memory 1801 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0234] The processor 1802 is coupled to the memory 1801 and is configured to execute the computer program stored in the memory 1801 for performing the method of the virtual power plant aggregation feasible region described in the foregoing embodiments.

[0235] When the processor 1802 executes the computer program for the fault calibration method of the backflow line direct power supply mode, the relationship between the fault impedance and the fault point position (the first distance) when the catenary (or the reinforcing wire) fails with the substation as the power supply side, and the relationship between the fault impedance and the fault point position (the second distance) when the catenary fails with the substation as the power supply side are determined by respectively analyzing the catenary (or the reinforcing wire) failure with the substation and the substation as the power supply side respectively; and the actual fault impedance is determined based on the actual electrical parameters in the power grid, and the values of the first distance and the second distance are obtained based on the above determined relationship, if the values of the two distances are (approximately) equal (i.e. the difference between the two is less than a preset threshold), it means that the catenary indeed has a fault point, and the fault point is at the position corresponding to the first distance obtained above, that is, the accurate positioning of the fault point is realized.

[0236] The processor 1802 can also implement other functions when executing the computer program in the memory 1801, in addition to the above functions, which can be referred to the description of the previous embodiments.

[0237] Further, as shown in Figure 18 , the computing device further includes a display 1804, a communication component 1803, a power supply component 1805, an audio component 1806 and other components. Figure 18 Some components are only schematically shown in the computing device, and it does not mean that the computing device only includes Figure 6 the components shown.

[0238] Correspondingly, the embodiment of the present application also provides a computer readable storage medium storing a computer program, which can implement the method provided by the above embodiments when the computer program is executed by a computer.

[0239] The device embodiments described above are only schematic, and the units shown as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement it without creative labor.

[0240] Those skilled in the art can clearly understand the implementation of the various embodiments by means of software and the necessary general hardware platform from the above description of the embodiments, and of course, the embodiments can also be implemented by hardware. Based on such an understanding, the above technical solutions, essentially or in other words, the part of the prior art that contributes to the present application, can be embodied in the form of a software product, and the computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0241] The above detailed description of the specific embodiments has further detailed the purposes, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fault calibration method for a direct power supply method with a return line, characterized in that, The method comprises: constructing a loop system composed of transmission conductors and return conductors in the traction network, determining the long loop unit impedance of the traction network by analyzing electrical parameters in the loop system; based on the long loop unit impedance, determining the relationship between the first fault impedance and the first distance when the catenary fails, with the traction network substation as the power supply end; the first distance represents the distance between the first preset fault point and the electrical connection point on the substation side; based on the long loop unit impedance, determining the relationship between the second fault impedance and the third distance when the catenary fails, with the substation as the power supply end; the third distance represents the distance between the third preset fault point and the electrical connection point on the substation side; determining the first fault impedance value based on the actual electrical parameter value of the substation; and determining the second fault impedance value based on the actual electrical parameter value of the substation; when the difference between the first distance and the third distance is less than a preset threshold, it is determined that the catenary fails, and the fault point is located at a distance of the first distance from the electrical connection point on the substation side; the first fault impedance represents the equivalent impedance of the fault occurring segment when the substation is the power supply; the second fault impedance represents the equivalent impedance of the fault occurring segment when the substation is the power supply.

2. The method of claim 1, wherein, The method further comprises: based on the long loop unit impedance, determining the relationship between the first fault impedance and the second distance when the reinforced wire fails, with the traction network substation as the power supply end; the second distance represents the distance between the second preset fault point and the electrical connection point on the substation side; based on the long loop unit impedance, determining the relationship between the second fault impedance and the fourth distance when the reinforced wire fails, with the substation as the power supply end; the fourth distance represents the distance between the fourth preset fault point and the electrical connection point on the substation side; determining the first fault impedance value based on the actual electrical parameter value of the substation; and determining the second fault impedance value based on the actual electrical parameter value of the substation; when the difference between the second distance and the fourth distance is less than a preset threshold, it is determined that the reinforced wire fails, and the fault point is located at a distance of the second distance from the electrical connection point on the substation side.

3. The method of claim 1, wherein, The method further comprises: the transmission conductor comprises a contact wire, a messenger wire and a reinforced wire; the return conductor comprises a rail 1, a rail 2, a return wire, a through ground wire and the ground.

4. The method of claim 1, wherein, The method further comprises: the method further comprises: each transmission conductor in the traction network forms a loop with each return conductor, constituting a loop system; any transmission conductor and any return conductor constitute a loop; based on the current characteristics in each loop, the self-inductance coefficient of each loop in the loop system and the mutual inductance coefficient between different loops are calculated respectively; based on the self-inductance coefficient and the mutual inductance coefficient, the unit length inductance matrix of each loop is determined; based on the characteristics of each loop itself and the characteristics of the shared conductors between different loops, the unit length resistance matrix of each loop is determined; based on the unit length inductance matrix of each loop and the unit length resistance matrix of each loop, the unit length impedance matrix of each loop is determined; Determine the long circuit equivalent impedance of the traction network based on the unit length impedance matrix of each circuit and electrical parameters in the traction network.

5. The method of claim 4, wherein, The first fault impedance is a parallel impedance of a first spatial circuit impedance and a second spatial circuit impedance; The first spatial circuit is a circuit formed by a traction substation side contact net electric connection point and a short circuit fault point, and the second spatial circuit is a circuit formed by a traction substation side reinforced wire electric connection point, a substation side electric connection point, a contact net, a reinforced wire, and the substation side electric connection point. The first spatial circuit is a circuit formed by a traction substation side contact net electric connection point and a short circuit fault point, and the second spatial circuit is a circuit formed by a traction substation side reinforced wire electric connection point, a substation side electric connection point, a contact net, a reinforced wire, and the substation side electric connection point.

6. The method of claim 5, wherein, The first spatial circuit is a circuit formed by a traction substation side contact net electric connection point and a short circuit fault point, and the second spatial circuit is a circuit formed by a traction substation side reinforced wire electric connection point, a substation side electric connection point, a contact net, a reinforced wire, and the substation side electric connection point. The determination of the second spatial circuit impedance specifically includes: Determine a spatial magnetic field matrix of the second space based on magnetic fluxes generated by each circuit in the circuit system in the second space; Derive the spatial magnetic field matrix with respect to time, and determine a voltage variation matrix of the second space based on voltage drop characteristics of each circuit; Transform the voltage variation matrix based on relationships between contact net circuit currents and reinforced wire circuit currents to determine currents of each circuit, and conductor currents and current distribution proportions in the circuit; 7. The method of claim 5, wherein, Determine the second spatial circuit impedance based on the conductor currents and the current distribution proportions. The determination of the first spatial circuit impedance specifically includes: Determine a spatial magnetic field matrix of the first space based on magnetic fluxes generated by each circuit in the circuit system in the first space; Derive the spatial magnetic field matrix with respect to time, and determine a voltage variation matrix of the first space based on voltage drop characteristics of each circuit; Transform the voltage variation matrix based on relationships between contact net circuit currents and reinforced wire circuit currents, and adjust contact net current proportions and reinforced wire current proportions by moving a short circuit fault point on the contact net, and determine currents of each circuit, and conductor currents and current distribution proportions in the circuit when a voltage drop of the first spatial circuit is equal to a voltage drop of the second spatial circuit; 8. A fault marking device with a direct power supply through a return line, characterized in that Determine the first spatial circuit impedance based on the conductor currents and the current distribution proportions. The method includes: A long circuit unit impedance calculation unit is configured to construct a circuit system composed of transmission conductors and return conductors in a traction network, and determine a long circuit unit impedance of the traction network by analyzing electrical parameters in the circuit system; A first relationship determination unit is configured to determine a relationship between a first fault impedance and a first distance when a contact net fails based on the long circuit unit impedance with a traction network substation as a power supply end; The first distance represents a distance between a first preset fault point and a substation side electric connection point; A second relationship determination unit is configured to determine a relationship between a second fault impedance and a third distance when the contact net fails based on the long circuit unit impedance with a substation as a power supply end; The third distance represents a distance between a third preset fault point and an electric connection point on the substation side; The fault impedance calculation unit determines the first fault impedance value based on actual electric parameter values of the substation; and determines the second fault impedance value based on actual electric parameter values of the subarea; The fault calibration unit determines that the overhead contact system is faulty and the fault point is located at a first distance from the electric connection point on the substation side when a difference between the first distance and the third distance is less than a preset threshold. The first fault impedance represents an equivalent impedance of a fault occurring segment when the substation is a power source; and the second fault impedance represents an equivalent impedance of a fault occurring segment when the subarea is a power source.

9. An electronic device, comprising: The method comprises: The processor, the memory and the program or instructions stored in the memory and executable on the processor are used to implement the steps of the method according to any one of claims 1-7.

10. A storage medium, characterized by The storage medium stores the program or instructions, and the program or instructions are executable on the processor to implement the steps of the method according to any one of claims 1-7. ​

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