Simulation calculation method and device for urban rail transit traction power supply system

Abstract

The application provides a simulation calculation method of a traction power supply system of urban rail transit, comprising the following steps: constructing a locomotive load model, establishing a locomotive operation state information table of a unified time section, combining the position of the locomotive with the position of a traction station in a line, and obtaining a topology structure analysis of different time sections; constructing a traction power supply system model, obtaining rated voltage, line length, line unit impedance and traction station position; simulating a plurality of locomotives starting from a vehicle depot and running from a first end of the line to a last end of the line, obtaining the power and position values of each locomotive according to the locomotive load model, and then substituting the power and position values into the traction power supply system model to complete power flow calculation of a DC traction network, and obtaining the current, voltage of the locomotive, bus voltage and feeder current values of the traction station; the application can simulate the power of the train under different operation states, and calculate the bus voltage and feeder current of each traction station of the traction power supply system.

Description

Technical Field

[0001] This invention relates to the field of urban rail transit traction power supply technology, and in particular to a simulation calculation method and apparatus for urban rail transit traction power supply systems. Background Technology

[0002] Currently, the operational scale of urban rail transit in my country has reached 11,224.54 kilometers, with over 300 operating lines. More and more cities are constructing rail transit systems based on demand. Rail transit trains typically require DC power supply; the AC power from the medium-voltage ring network is converted into DC power by converters to supply electricity to the trains. Trains are high-power sliding loads, exhibiting traction, inertia, and braking conditions. The simultaneous presence of multiple trains on a line leads to a complex load situation in the power supply system, making analysis challenging. During construction, the location and capacity of traction substations need to be determined based on load demand, ensuring that the power supply capacity of each traction substation meets requirements under different operating conditions. During operation, the determination and adjustment of train timetables also necessitate determining the power supply capacity of the traction power supply system.

[0003] In view of the above problems, this application proposes a simulation calculation method for urban rail transit traction power supply systems. This method can simulate the traction inertia and braking operation of multiple trains on a line, calculate the power of each train during operation, and then combine it with the traction power supply system model to complete the simulation calculation from the source side to the load side, obtaining the bus voltage and feeder current of each traction substation. Summary of the Invention

[0004] The simulation calculation method for urban rail transit traction power supply system includes the following steps:

[0005] Constructing a locomotive load model, the locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during its motion, establishing a locomotive operating status information table with a unified time section, and combining the locomotive position with the position of the traction substation on the line to obtain topological structure analysis at different time sections;

[0006] A traction power supply system model is constructed, and the actual traction substation is equivalent to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained.

[0007] Multiple locomotives are simulated to start from the depot and run from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained based on the locomotive load model. These values ​​are then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and the current, voltage, bus voltage of the traction substation, and feeder current values ​​of the locomotives are obtained.

[0008] Furthermore, when performing topological structure analysis at different time points,

[0009] Trains and traction substations need to be numbered, with the traction substation number first and the locomotive number second. The positive direction should be the same as the locomotive's running direction, i.e., from up to down.

[0010] The train positions and traction substation positions are sequentially sorted and numbered. The sorted and numbered trains and traction substations are considered as nodes, and adjacent nodes are considered as branches, resulting in the matrix [Loc]. m×3 The number of rows is m, which represents the number of branches. The preceding and following node numbers of each branch are stored in [Loc]. m×3 The first, second, and third columns represent the distance difference between the preceding and following nodes, which is the length of the branch.

[0011] Then, based on the relative position of each node and the unit impedance of the contact network, a node admittance matrix is ​​established.

[0012] Furthermore, the power flow calculation of the DC traction network is solved using the Newton-Raphson iterative method.

[0013] Furthermore, in the process of calculating the power flow of the DC traction network, locomotives that have not started in the station or depot need to be deleted during the iteration process. During the iteration, an initial value needs to be assigned to the voltage of each traction station in the first section. The traction station voltage value input to each section at subsequent times is the calculation result of the previous section. The solution is performed iteratively. Through iteration, the voltage value of each node, branch current, and node power can be obtained.

[0014] Furthermore, based on the voltage values ​​of the preceding and following nodes of each branch, the branch voltage is calculated. The branch voltage is then multiplied by the admittance of the corresponding branch to obtain the branch current. Then, based on the number of the preceding and following nodes, the feeder current value of each traction substation is selected from the branch current, and the feeder current of each substation is ordered as the up-left feeder current, the up-right feeder current, the down-right feeder current, and the down-left feeder current.

[0015] Furthermore, during the topology analysis process, [Loc] m×3 The system updates once per calculation cycle to ensure it matches the real-time dynamic process of the locomotive.

[0016] Furthermore, when obtaining the speed, acceleration, position, and power values ​​of the train during its motion, it is necessary to first fit the traction force curve under traction conditions and the braking force curve under braking conditions.

[0017] The traction force curve consists of four parts, which respectively simulate four states: constant torque state, constant power state, inertial state, and natural characteristics. In the constant torque state, the traction force remains constant. In the constant power state, the traction force gradually decreases with the increase of speed, showing a hyperbolic relationship. In the natural characteristics state, the traction force is inversely proportional to the square of the speed. In the inertial state, the traction force is 0.

[0018] The braking force curve in the braking state is the same as the traction force curve in the traction state, but it is negative.

[0019] A simulation computing device for urban rail transit traction power supply systems includes:

[0020] The locomotive load model construction module is used to construct a locomotive load model. The locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during the movement process; establishing a locomotive operation status information table with a unified time section; and combining the locomotive position with the position of the traction substation in the line to obtain topological structure analysis at different time sections.

[0021] The traction power supply system model building module is used to build a traction power supply system model, which equates the actual traction substation to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained.

[0022] The voltage and current acquisition module is used to simulate multiple locomotives starting from the depot and running from the beginning to the end of the line. Based on the locomotive load model, the power and position values ​​of each locomotive are obtained, and then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and obtain the current and voltage of the locomotives, the bus voltage of the traction substation, and the feeder current values.

[0023] A computing device, comprising:

[0024] One or more processing units;

[0025] A storage unit is used to store one or more programs.

[0026] When the one or more programs are executed by the one or more processing units, the one or more processing units perform the simulation calculation method for the urban rail transit traction power supply system as described above.

[0027] A computer-readable storage medium having processor-executable non-volatile program code, wherein the computer program, when executed by a processor, implements the steps of the simulation calculation method for an urban rail transit traction power supply system as described above.

[0028] The advantages and positive effects of this invention are:

[0029] This invention proposes a simulation calculation method for urban rail transit traction power supply system. This method can simulate the power of trains under different operating conditions and calculate the bus voltage and feeder current of each traction substation in the traction power supply system. Attached Figure Description

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless specifically indicated, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0031] Figure 1 This is an operational topology diagram of two traction stations at a certain moment, provided in Embodiment 1 of the present invention;

[0032] Figure 2(a) is a topology diagram of the three traction stations at a certain moment provided in Embodiment 1 of the present invention;

[0033] Figure 2(b) is a diagram showing the operation topology of the three traction stations provided in Embodiment 1 of the present invention, which differs from that in Figure 2(a) at a certain moment;

[0034] Figure 3 This is a schematic diagram of the feeder numbering of the traction station provided in Embodiment 1 of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] Example 1

[0038] The simulation calculation method for urban rail transit traction power supply system provided in this embodiment includes the following steps:

[0039] Constructing a locomotive load model, the locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during its motion, establishing a locomotive operating status information table with a unified time section, and combining the locomotive position with the position of the traction substation on the line to obtain topological structure analysis at different time sections;

[0040] A traction power supply system model is constructed, and the actual traction substation is equivalent to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained.

[0041] Multiple locomotives are simulated to start from the depot and run from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained based on the locomotive load model. These values ​​are then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and the current, voltage, bus voltage of the traction substation, and feeder current values ​​of the locomotives are obtained.

[0042] When performing topological structure analysis at different time points,

[0043] Trains and traction substations need to be numbered, with the traction substation number first and the locomotive number second. The positive direction should be the same as the locomotive's running direction, i.e., from up to down.

[0044] The train positions and traction substation positions are sequentially numbered. The trains and traction substations after the sorting and numbering are regarded as nodes, and the distances between adjacent nodes are considered as branches. The absolute distances between the trains and traction substations at different time sections are determined, and the matrix [Loc] is obtained. m×3 The number of rows is m, which represents the number of branches. The preceding and following node numbers of each branch are stored in [Loc]. m×3 The first, second, and third columns represent the distance difference between preceding and following nodes, which is the length of the branch; during topology analysis, [Loc] m×3 The calculation is updated once per cycle to ensure that it matches the real-time dynamic process of the locomotive.

[0045] Then, based on the relative position of each node and the unit impedance of the contact network, a node admittance matrix is ​​established.

[0046] The power flow calculation of the DC traction network is solved using the Newton-Raphson iterative method. During the power flow calculation of the DC traction network, locomotives that are not started in the station or depot need to be deleted during the iteration process. During iteration, an initial value needs to be assigned to the voltage of each traction substation in the first section. The traction substation voltage value input to each section at subsequent times is the calculation result of the previous section. Through iteration, the voltage value of each node, branch current, and node power can be obtained. Based on the voltage values ​​of the nodes before and after each branch, the branch voltage is calculated. The branch voltage is then multiplied by the admittance of the corresponding branch to obtain the branch current. Then, the feeder current value of each traction substation is selected from the branch current according to the number of the nodes before and after. The feeder current of each substation is ordered as the upstream left feeder current, the upstream right feeder current, the downstream right feeder current, and the downstream left feeder current.

[0047] Specifically, locomotives that are not started in the station or depot need to be deleted during the iteration process. When deleting a locomotive, the locomotive is judged to be started based on its relative position and speed. If the locomotive speed is zero, it is judged to be not started. If the locomotive is located at a traction substation, the beginning or end of the line, it is judged to be not started.

[0048] When obtaining the speed, acceleration, position and power values ​​of a train during its motion, it is necessary to first fit the traction force curve of the traction state and the braking force curve of the braking state.

[0049] The traction force curve consists of four parts, which respectively simulate four states: constant torque state, constant power state, inertial state, and natural characteristics. In the constant torque state, the traction force remains constant. In the constant power state, the traction force gradually decreases with the increase of speed, showing a hyperbolic relationship. In the natural characteristics state, the traction force is inversely proportional to the square of the speed. In the inertial state, the traction force is 0.

[0050] The braking force curve in the braking state is the same as the traction force curve in the traction state, but it is negative.

[0051] The above traction force curve can be expressed by the following formula, where F const For constant torque, P const Here, k is the constant power value, and k1 is the natural characteristic coefficient.

[0052]

[0053] Let f be the resistance of the locomotive, which is simulated by a quadratic function in two variables, and m be the mass of the locomotive.

[0054] The equations of motion are as follows:

[0055] Update train speed based on acceleration calculation.

[0056] v=v0+t(Ff) / m

[0057] Calculate the train's current distance.

[0058] x = v0t + (Ff)t 2 / 2m

[0059] Calculate the train power P

[0060] P = Fv;

[0061] Based on the characteristics of traction load, and taking the departure interval and the maximum number of vehicles allowed to run on the line as the basis, the scenario of multiple vehicles running at the same time is simulated. The number of locomotives is the maximum number of vehicles running on the line. All vehicles waiting to start are stopped in the depot, and their speed and power are both 0.

[0062] The system calculates information such as operating speed, traction force, locomotive power, operating status, and acceleration for each train at different operating times. It then integrates the calculated information from different locomotives, aligning the results across all locomotives using time as the reference axis, and establishes a unified time-section locomotive operating status information table, including the train's position x1 to x2. k With power P1~P k , where k is the number of locomotives, including the number of locomotives that are not in operation in the depot;

[0063] The train operation status information table records the location and power values ​​of all locomotives on the line at different times. By combining the locomotive locations with the locations of traction substations on the line, the topology of different time sections can be analyzed. Figure 1 The line topology state at a certain moment;

[0064] The topology analysis process requires numbering trains and traction substations, with the substation number preceding the locomotive number. The positive direction is chosen to be the same as the locomotive's running direction, i.e., from uphill to downhill. The positions of trains and traction substations are then sequentially numbered, and the numbered trains and substations are considered nodes, with adjacent nodes forming branches. The absolute distances between trains and substations at different time points are then determined. The output matrix is ​​[Loc]. m×3 The number of rows is m, which represents the number of branches. The preceding and following node numbers of each branch are stored in [Loc]. m×3 The first and second columns; the third column represents the distance difference between the preceding and following nodes, which is the length of the branch.

[0065] Then, based on the relative position of each node and the unit impedance of the contact network, a node admittance matrix is ​​established;

[0066] During topology analysis, [Loc] m×3 The calculation is updated once per cycle to ensure it matches the real-time dynamic process of the locomotive.

[0067] by Figure 1 Let's take an example to explain:

[0068] The diagram shows two traction depots, numbered ① and ②, with kilometer markers of 2km and 4km respectively. There are four locomotives on the line, numbered ③ through ⑥, with kilometer markers of 1km, 3km, and 5km for the uphill section. As can be seen from the forward direction, the downhill section starts at kilometer 6, so the downhill kilometer marker is 9km. Branch lines are numbered 1 through 6 in the diagram, and each branch line has [Loc] at its preceding and following nodes. m×3 The first and second columns; based on the kilometer markers at each node, the length of each road can be calculated. [Loc] m×3 Column 3; taking Figure 2 as an example [Loc] m×3 The matrix can be represented as:

[0069]

[0070] Based on the equivalent DC power supply of the actual traction substation, each DC power supply is connected by a transmission line at one end. The unit impedance of the transmission line is the same as the field parameters. The Newton-Raphson iterative method is used for solving. During the solution process, locomotives that are not started in the station or depot need to be deleted during the iteration process. A reasonable initial value needs to be assigned to the voltage of each traction substation in the first section. The traction substation voltage value input in each section at subsequent times is the calculation result of the previous section, and the solution is iteratively performed.

[0071] The locomotive removal process refers to determining whether a locomotive has started based on its relative position and speed.

[0072] According to the locomotive starting criteria: if the locomotive speed is zero, it is judged as not starting; if the locomotive is located at a traction depot, the beginning or end of the line, it is judged as not starting.

[0073] Locomotive nodes that are determined to be not started should be deleted, and the corresponding node admittance matrix should also be adjusted according to the actual situation.

[0074] The generation of the node admittance matrix requires the generation of the branch correlation matrix based on basic circuit theory;

[0075] This process is based on Figure 2(a) , 2(b) For example, we will explain in detail.

[0076] In Figure 2(a), there are 3 traction substations. The maximum number of locomotives operating in the uphill direction is 5, and the maximum number of locomotives operating in the downhill direction is 5. The substations and locomotive nodes are numbered as ① to ⑨. The branches between two nodes are known from Section 4, and their lengths are numbered as 1 to 10. According to the locomotive starting criterion, one locomotive in the uphill direction and three locomotives in the downhill direction have not started. These need to be deleted during the analysis. According to the theory of circuit equations in matrix form, the branch correlation matrix A is written. The positive direction is defined as the direction of departure from the end of the line as positive, and the direction of injection nodes as negative. The number of rows in matrix A is the number of nodes, and the number of columns is the number of branches.

[0077]

[0078] Branch admittance matrix [Y] Branch ] m×m With Part 4 [Loc] m×3 The third column stores information related to the line length. The branch admittance matrix is ​​a diagonal matrix with the same dimension as the number of branches. The diagonal elements are the line unit impedance multiplied by the length of each segment.

[0079] Node admittance matrix Y n Calculation method for Y: n =AY Branch A T ;

[0080] Figure 2(b) shows a moment after the state in Figure 2(a). At this time, all the locomotives going up have started, but one locomotive has arrived at the station. According to the locomotive starting criterion, one locomotive going up has not started, and one locomotive going down has not started. The numbers of the traction substation and locomotive nodes need to be completely updated, as shown in numbers ① to ⑩. The distance between two nodes is a branch, the length of which can be known from section 4, and the numbers are shown in numbers 1 to 10. At this time, the branch correlation matrix A, the branch admittance matrix, and the node admittance matrix all need to be updated. Among them, the branch admittance matrix [Y Branch ] m×m The calculation method remains the same, but the number of rows in the correlation matrix A increases, as shown below:

[0081]

[0082] Node admittance matrix Y n The calculation method is the same as above: Y n =AY Branch A T

[0083] The iterative solution process is the power flow calculation process. The Newton-Raphson method is used to complete the simulation calculation of the flexible DC traction power supply system for urban rail transit. The process is as follows:

[0084] For a DC traction network with n nodes, the node voltage and current vectors are:

[0085] U = [U1 U2…U] n ] T

[0086] I = [I1 I2…I] n ] T

[0087] According to the admittance calculation formula G = I / U, the nodal admittance matrix can be obtained as follows:

[0088]

[0089] The power flow distribution of the DC network is determined by the node voltage and line impedance of the oil traction substation. Taking the power direction injected into the node as positive, the injected current, active power, and power deviation of node i are expressed as follows:

[0090]

[0091] In the formula, U i Let I be the voltage at node i. i Let G be the current in branch i. ij P is the element in the i-th row and j-th column of the nodal admittance matrix; di P is the active power injected into node i of the power source. ti Let be the load power of node i.

[0092] The corrected equation for DC voltage including nodes is:

[0093]

[0094] The modified equation is solved using the Newton-Raphson method, and the corresponding Jacobian matrix can be represented as J, satisfying the following relation:

[0095]

[0096] In the formula, ΔP=[ΔP1,ΔP2,…ΔP n ] T The active power deviation vector of the node;

[0097] U = [U1, U2, ... U n ] T The node DC voltage vector;

[0098] ΔU=[U1 / ΔU1,U2 / ΔU2,…U n / ΔU n ] T This is the DC voltage correction amount for the node;

[0099] This is the value of the kth iteration.

[0100] Through the above iterations, the voltage values ​​of each node, branch current, and node power can be obtained.

[0101] After the calculations are completed, the results are organized and summarized, outputting the voltage of each traction substation, the current of the four feeders, and the voltage and current values ​​of the locomotive. Based on the voltage of the preceding and following nodes of each route, the branch voltage is calculated. The branch voltage is then multiplied by the corresponding branch admittance to obtain the branch current. The feeder current value for each traction substation is then selected from the branch currents according to the node numbers. The feeder currents for each substation are ordered as follows: upward left feeder current, upward right feeder current, downward right feeder current, and downward left feeder current, labeled as follows: Figure 3 As shown.

[0102] Example 2

[0103] This embodiment provides a simulation computing device for an urban rail transit traction power supply system, including:

[0104] The locomotive load model construction module is used to construct a locomotive load model. The locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during the movement process; establishing a locomotive operation status information table with a unified time section; and combining the locomotive position with the position of the traction substation in the line to obtain topological structure analysis at different time sections.

[0105] The traction power supply system model building module is used to build a traction power supply system model, which equates the actual traction substation to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained.

[0106] The voltage and current acquisition module is used to simulate multiple locomotives starting from the depot and running from the beginning to the end of the line. Based on the locomotive load model, the power and position values ​​of each locomotive are obtained, and then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and obtain the current and voltage of the locomotives, the bus voltage of the traction substation, and the feeder current values.

[0107] A computing device is also provided, comprising:

[0108] One or more processing units;

[0109] A storage unit is used to store one or more programs.

[0110] When the one or more programs are executed by the one or more processing units, the one or more processing units execute the simulation calculation method for the urban rail transit traction power supply system provided in this embodiment. It should be noted that the computing device may include, but is not limited to, processing units and storage units. Those skilled in the art will understand that the inclusion of processing units and storage units in the computing device does not constitute a limitation on the computing device. It may include more components, or combine certain components, or different components. For example, the computing device may also include input / output devices, network access devices, buses, etc.

[0111] A computer-readable storage medium having processor-executable non-volatile program code, wherein the computer program, when executed by a processor, implements the steps of the simulation calculation method for the urban rail transit traction power supply system provided in this embodiment. It should be noted that the readable storage medium can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. The program contained on the readable medium can be transmitted using any suitable medium, including, but not limited to, wireless, wired, optical fiber, RF, etc., or any suitable combination thereof. For example, program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as C or similar programming languages. The program code can be executed entirely on a user's computing device, partially on a user's device, as a standalone software package, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to the user's computing device via any type of network—including a local area network (LAN) or a wide area network (WAN), or they can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation calculation method for urban rail transit traction power supply systems, characterized in that, Includes the following steps: Constructing a locomotive load model, the locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during its motion, establishing a locomotive operating status information table with a unified time section, and combining the locomotive position with the position of the traction substation on the line to obtain topological structure analysis at different time sections; A traction power supply system model is constructed, and the actual traction substation is equivalent to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained. Multiple locomotives are simulated to start from the depot and run from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained based on the locomotive load model. These values ​​are then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and the current, voltage, bus voltage of the traction substation, and feeder current values ​​of the locomotives are obtained. The power flow calculation of the DC traction network is solved using the Newton-Raphson iterative method. In the process of calculating the power flow of the DC traction network, locomotives that have not started in the station or depot need to be deleted during the iteration process. During the iteration, an initial value needs to be assigned to the voltage of each traction station in the first section. The traction station voltage value input to each section at subsequent times is the calculation result of the previous section. The solution is obtained through iteration. Through iteration, the voltage value of each node, branch current and node power can be obtained. The branch voltage is calculated based on the voltage values ​​of the preceding and following nodes of each branch. The branch voltage is then multiplied by the admittance of the corresponding branch to obtain the branch current. The feeder current value of each traction substation is selected from the branch currents according to the numbers of the preceding and following nodes. The feeder currents of each substation are ordered as follows: up-line left feeder current, up-line right feeder current, down-line right feeder current, and down-line left feeder current. When obtaining the speed, acceleration, position and power values ​​of a train during its motion, it is necessary to first fit the traction force curve of the traction state and the braking force curve of the braking state. The traction force curve consists of four parts, which respectively simulate four states: constant torque state, constant power state, inertial state, and natural characteristics. In the constant torque state, the traction force remains constant. In the constant power state, the traction force gradually decreases with the increase of speed, showing a hyperbolic relationship. In the natural characteristics state, the traction force is inversely proportional to the square of the speed. In the inertial state, the traction force is 0. The braking force curve in the braking state is the same as the traction force curve in the traction state, but it is negative.

2. The simulation calculation method for urban rail transit traction power supply system according to claim 1, characterized in that, When performing topological structure analysis at different time points, Trains and traction substations need to be numbered, with the traction substation number first and the locomotive number second. The positive direction should be the same as the locomotive's running direction, i.e., from up to down. The train positions and traction substation positions are sequentially sorted and numbered. The sorted and numbered trains and traction substations are considered as nodes, and the relationships between adjacent nodes are considered as branches, thus obtaining a matrix. The number of rows is m That is, the number of branches, and the preceding and following node numbers of each branch are stored separately. The first, second, and third columns represent the distance difference between the preceding and following nodes, which is the length of the branch. Then, based on the relative position of each node and the unit impedance of the contact network, a node admittance matrix is ​​established.

3. The simulation calculation method for urban rail transit traction power supply system according to claim 2, characterized in that, During topology analysis The system updates once per calculation cycle to ensure it matches the real-time dynamic process of the locomotive.

4. A simulation computing device for urban rail transit traction power supply system, used to implement the method described in any one of claims 1-3, characterized in that, include: The locomotive load model construction module is used to construct a locomotive load model. The locomotive load model includes: acquiring the speed, acceleration, position and power values ​​of the train during the movement process; establishing a locomotive operation status information table with a unified time section; and combining the locomotive position with the position of the traction substation in the line to obtain topological structure analysis at different time sections. The traction power supply system model building module is used to build a traction power supply system model, which equates the actual traction substation to a DC power source. Each DC power source is connected by a transmission line, and the rated voltage, line length, line unit impedance, and traction substation location are obtained. The voltage and current acquisition module is used to simulate multiple locomotives starting from the depot and running from the beginning to the end of the line. Based on the locomotive load model, the power and position values ​​of each locomotive are obtained, and then substituted into the traction power supply system model to complete the power flow calculation of the DC traction network, and obtain the current and voltage of the locomotives, the bus voltage of the traction substation, and the feeder current values.

5. A computing device, characterized in that: include: One or more processing units; A storage unit is used to store one or more programs. Wherein, when the one or more programs are executed by the one or more processing units, the one or more processing units perform the method as described in any one of claims 1 to 3.

6. A computer-readable storage medium having processor-executable non-volatile program code, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 3.

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