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

Abstract

The invention provides a simulation calculation method of an urban rail transit traction power supply system, which comprises the following steps of: constructing a locomotive load model, establishing a locomotive running state information table with a unified time section, and combining the position of a locomotive with the position of a traction station in a line to obtain topological structure analysis of different time sections; constructing a traction power supply system model, and obtaining rated voltage, line length, line unit impedance and traction position; simulating that a plurality of locomotives start from a vehicle depot and run from the head end of a line to the tail end of the line, obtaining power and position values of the locomotives according to a locomotive load model, substituting the power and position values into a traction power supply system model to complete load flow calculation of a direct-current traction network, and obtaining current and voltage of the locomotives and bus voltage and feeder current values of a traction station; according to the invention, the power of the train in different operation states can be simulated, and the bus voltage and feeder current of each traction station of the traction power supply system can be calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of urban rail transit traction power supply, in particular to a simulation calculation method and a device for an urban rail transit traction power supply system. Background Art

[0002] At present, the operating scale of urban rail transit in my country has reached 11,224.54 kilometers, and the number of operating lines has exceeded 300. More and more cities are carrying out rail transit construction according to demand. Rail transit trains usually require DC power supply. The AC power of the medium-voltage ring network is converted into DC power through a converter to provide power for the train. The train is a high-power sliding load, with three working conditions: traction, inertia and braking. There are multiple trains on the line at the same time, which makes the load situation of the power supply system more complicated and difficult to analyze. During the construction process, it is necessary to complete the site selection and capacity determination of the traction depot according to the load demand, and determine the power supply capacity of each traction depot under different working conditions to meet the requirements; during the operation process, the determination and adjustment of the train timetable also requires the determination of 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 the urban rail transit traction power supply system, which can simulate the traction inertia and braking operation status of multiple trains in the line, calculate the power of each train during operation, and then combine the traction power supply system model to complete the simulation calculation from the source side to the load side, and obtain the bus voltage and feeder current of each traction station. . Summary of the invention

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

[0005] Constructing a locomotive load model, the locomotive load model includes: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections;

[0006] Construct a traction power supply system model, equating the actual traction station to a DC power supply, connecting each DC power supply with a transmission line, and obtaining the rated voltage, line length, line unit impedance, and traction station location;

[0007] It simulates multiple locomotives starting from the depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current values.

[0008] Furthermore, when obtaining topological structure analysis at different time sections,

[0009] The train and the traction depot need to be numbered, with the traction depot numbered first and the locomotive numbered last. The positive direction should be the same as the locomotive running direction, that is, from up to down.

[0010] The train positions and traction depot positions are sorted and numbered in sequence, and the sorted and numbered trains and traction depots are regarded as nodes, and the adjacent nodes are branches, and the matrix [Loc] is obtained. m×3 , where the number of rows is m, i.e. the number of branches, and the number of the front and back nodes of each branch are respectively stored in [Loc] m×3 The first and second columns of the , and the third column are the distance difference between the front and rear nodes, which is the length of the branch;

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

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

[0013] Furthermore, in the power flow calculation process of the DC traction network, locomotives that are 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, and then the voltage value of the traction station input in each section is the calculation result of the previous section, and the iterative solution is performed. Through iteration, the voltage value of each node, branch current, and node power can be solved.

[0014] Furthermore, the branch voltage is calculated based on the voltage values ​​of the front and rear nodes of each branch, and the branch voltage is multiplied by the admittance of the corresponding branch to obtain the branch current. Then, the feeder current value of each traction station is selected from the branch current according to the numbers of the front and rear nodes, and the feeder current of each station is arranged in the order of the upstream left feeder current, the upstream right feeder current, the downstream right feeder current and the downstream left feeder current.

[0015] Furthermore, in the topological structure analysis process, [Loc] m×3 It will be updated once every calculation cycle to ensure that it is consistent with the real-time dynamic process of the locomotive.

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

[0017] The traction force curve consists of four parts, which respectively simulate the constant torque state, constant power state, inertia 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, presenting a hyperbolic relationship. In the natural characteristic state, the traction force is inversely proportional to the square of the speed. In the inertia 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 is a negative value.

[0019] The simulation computing device of the urban rail transit traction power supply system includes:

[0020] The locomotive load model building module is used to build a locomotive load model, which includes: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections;

[0021] The traction power supply system model building module is used to build the traction power supply system model, which equates the actual traction station to a DC power supply, connects each DC power supply with a transmission line, and obtains the rated voltage, line length, line unit impedance, and traction station location;

[0022] The voltage and current acquisition module is used to simulate multiple locomotives starting from the vehicle depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current value.

[0023] A computing device comprising:

[0024] one or more processing units;

[0025] A storage unit for storing one or more programs,

[0026] Wherein, 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 of the urban rail transit traction power supply system as described above.

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

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

[0029] The present invention provides a simulation calculation method for an urban rail transit traction power supply system, which can simulate the power of a train under different operating conditions and calculate the bus voltage and feeder current of each traction station in the traction power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0031] Figure 1 The operation topology diagram of two traction stations at a certain moment provided by Embodiment 1 of the present invention;

[0032] FIG2(a) is an operation topology diagram of three traction stations at a certain moment provided by Embodiment 1 of the present invention;

[0033] FIG2(b) is an operation topology diagram of three traction stations provided in Embodiment 1 of the present invention at a certain moment different from that in FIG2(a);

[0034] Figure 3 A schematic diagram of the feeder numbering of a traction station provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] The simulation calculation method of the 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: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections;

[0040] Construct a traction power supply system model, equating the actual traction station to a DC power supply, connecting each DC power supply with a transmission line, and obtaining the rated voltage, line length, line unit impedance, and traction station location;

[0041] It simulates multiple locomotives starting from the depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current values.

[0042] When obtaining topological structure analysis at different time sections,

[0043] The train and the traction depot need to be numbered, with the traction depot numbered first and the locomotive numbered last. The positive direction should be the same as the locomotive running direction, that is, from up to down.

[0044] The train positions and traction depot positions are sorted and numbered in sequence, and the sorted and numbered trains and traction depots are regarded as nodes, and the adjacent nodes are branches. The absolute distance between the train and the traction depot at different time sections is determined, and the matrix [Loc] is obtained. m×3 , where the number of rows is m, i.e. the number of branches, and the number of the front and back nodes of each branch are respectively stored in [Loc] m×3 The first and second columns of the , and the third column are the distance difference between the front and rear nodes, that is, the length of the branch; in the topological structure analysis process, [Loc] m×3 It will be updated once in each calculation cycle to ensure that it is consistent with the real-time dynamic process of the locomotive;

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

[0046] The power flow calculation of the DC traction network is solved by the Newton-Raphson iteration method; during the power flow calculation process of the DC traction network, locomotives that are not started in the station or vehicle 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, and then the voltage value of the traction station input in each section at each moment is the calculation result of the previous section, and the iterative solution is performed. Through the iteration, the voltage value of each node, the branch current, and the node power can be solved; according to the voltage values ​​of the front and rear nodes of each branch, the branch voltage is calculated, and the branch voltage is multiplied by the admittance of the corresponding branch to obtain the branch current, and then the feeder current value of each traction station is selected from the branch current according to the number of the front and rear nodes, and the feeder current of each station is arranged in the order of the upward left feeder current, the upward right feeder current, the downward right feeder current and the downward left feeder current.

[0047] Specifically, the locomotives that are not started in the station or depot need to be deleted during the iteration process. When judging the locomotive deletion: whether the locomotive is started is determined based on the relative position and speed of the locomotive. If the locomotive speed is zero, it is judged as not started; if the locomotive is located at the traction station, the beginning or the end of the line, it is judged as not started.

[0048] When obtaining the speed, acceleration, position and power values ​​of the train during movement, 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 the constant torque state, constant power state, inertia 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, presenting a hyperbolic relationship. In the natural characteristic state, the traction force is inversely proportional to the square of the speed. In the inertia 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 is a negative value.

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

[0052]

[0053] Assume that the resistance of the locomotive simulated by a two-variable quadratic function is f, and the mass of the locomotive is m;

[0054] The equation of motion is as follows:

[0055] Update the train speed at the moment based on acceleration calculation

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

[0057] Calculate the train running distance at the current time

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

[0059] Calculate the train power P

[0060] P = Fv;

[0061] According to the characteristics of traction load, based on the departure interval and the maximum number of vehicles allowed to run on the line, the situation of multiple vehicles running at the same time is simulated. The number of locomotives is the maximum number of vehicles on the line. The vehicles waiting to start are all parked in the vehicle depot, and their speed and power are both 0.

[0062] Calculate the running speed, traction, locomotive power, running status and acceleration of each train at different running times, integrate the calculation information of different locomotives, align the calculation results of each locomotive with time as the reference axis, and establish a locomotive running status information table of a unified time section, including the train positions x1~x k With power P1~P k , where k is the number of locomotives, including the number of vehicles that are not started in the depot;

[0063] The train operation status information table records the position and power values ​​of all locomotives on the line at different times. Combining the locomotive position with the position of the traction station on the line, the topological structure of different time sections can be analyzed. Figure 1 is the line topology state at a certain moment;

[0064] The topological structure analysis process requires numbering the train and the traction depot, with the traction depot numbered first and the locomotive numbered last; the positive direction is the same as the locomotive running direction, that is, from up to down; the train positions and traction depot positions are sorted and numbered in turn, and the sorted and numbered trains and traction depots are regarded as nodes, and the adjacent nodes are branches, and the absolute distance between the train and the traction depot at different time sections is determined. Output matrix [Loc] m×3 , where the number of rows is m, i.e. the number of branches, and the number of the front and back nodes of each branch are respectively stored in [Loc] m×3 The first and second columns are the distance difference between the front and rear nodes, which is the length of the branch.

[0065] Then, according to the relative position of each node and the unit impedance of the overhead line, the node admittance matrix is ​​established;

[0066] During topological structure analysis, [Loc] m×3 It will be updated once every calculation cycle to ensure that it is consistent with the real-time dynamic process of the locomotive.

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

[0068] There are 2 traction stations in the diagram, numbered ① and ②, with kilometer marks of 2km and 4km respectively. There are 4 locomotives on the line, numbered ③ to ⑥, and the kilometer marks of the up-going vehicles are 1km, 3km and 5km respectively. From the positive direction, we can see that the starting position of the down-going distance starts at 6km, so the kilometer mark of the down-going vehicle is 9km. The branch numbers are numbered 1 to 6 in the diagram, and the front and rear nodes of each branch have [Loc] m×3 The first and second columns of the ; According to the kilometer mark of each node, the length of each road can be calculated [Loc] m×3 Column 3; Take Figure 2 as an example [Loc] m×3 The matrix can be expressed as:

[0069]

[0070] According to the equivalent DC power supply of the actual traction station, each DC power supply is connected by a transmission line at one end, and the unit impedance of the transmission line is the same as the field parameter; the Newton-Raphson iteration method is used for solution; during the solution process, the locomotives that are parked at the station or not started in the depot need to be deleted during the iteration process; it is necessary to assign a reasonable initial value to the voltage of each traction station in the first section, and then the voltage value of the traction station input in each section at any time is the calculation result of the previous section, and it is solved iteratively;

[0071] The locomotive deletion process refers to: judging whether the locomotive is started according to the relative position and speed of the locomotive;

[0072] According to the locomotive start criterion: if the locomotive speed is zero, it is judged as not started; if the locomotive is located at the traction station, the beginning or the end of the line, it is judged as not started.

[0073] The locomotive nodes judged as 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 Figure 2(a) , 2(b) Take this as an example to explain in detail.

[0076] In Figure 2(a), there are 3 traction stations, the maximum number of locomotives in operation on the uplink is 5, and the maximum number of locomotives in operation on the downlink is 5. The numbering of the traction station and locomotive nodes is shown in serial numbers ① to ⑨. There is a branch between the two nodes, and the length can be known from Section 4. The serial numbers are shown in 1 to 10. According to the locomotive start criterion, it can be seen that there is one locomotive that has not started on the uplink and three locomotives that have not started on the downlink. They all need to be deleted during analysis. From the circuit equation theory in matrix form, it can be seen that the branch association matrix A is written. The positive direction sets the departure end as positive and the injection node as negative. The number of rows in the A matrix 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 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 unit impedance of the line multiplied by the length of each segment.

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

[0080] Figure 2(b) is a moment after the state of Figure 2(a). At this time, all the locomotives on the uplink have started, but there is a locomotive arriving at the station. According to the locomotive start criterion, one locomotive on the uplink has not started, and one locomotive on the downlink has not started. The numbers of the traction station and locomotive nodes need to be updated, as shown in numbers ① to ⑩. There is a branch between the two nodes. The length can be known from Section 4, and the numbers are shown as 1 to 10. At this time, the branch association 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 of remains unchanged, and the number of rows of the association 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 node admittance matrix can be obtained as:

[0088]

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

[0090]

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

[0092] The correction equation including the node DC voltage is:

[0093]

[0094] The Newton-Raphson method is used to solve the modified equation, and the corresponding Jacobian matrix can be expressed as J, which satisfies the relationship:

[0095]

[0096] Where, ΔP=[ΔP1, ΔP2, … ΔP n ] T is the node active power deviation vector;

[0097] U=[U1,U2,…U n ] T is the node DC voltage vector;

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

[0099] is the kth iteration value.

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

[0101] After the calculation is completed, the results are sorted and summarized, and the voltage of each traction station, the current of the four feeders, and the voltage and current values ​​of the locomotive are output; the branch voltage is calculated based on the voltage of the front and rear nodes of each road, and the branch voltage is multiplied by the admittance of the corresponding branch to obtain the branch current, and then the feeder current value of each traction station is selected from the branch current according to the number of the front and rear nodes. The order of the feeder current of each station is the upper left feeder current, the upper right feeder current, the lower right feeder current and the lower left feeder current, and the labels are as follows: Figure 3 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 building module is used to build a locomotive load model, which includes: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections;

[0105] The traction power supply system model building module is used to build the traction power supply system model, which equates the actual traction station to a DC power supply, connects each DC power supply with a transmission line, and obtains the rated voltage, line length, line unit impedance, and traction station location;

[0106] The voltage and current acquisition module is used to simulate multiple locomotives starting from the vehicle depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current value.

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

[0108] one or more processing units;

[0109] A storage unit for storing one or more programs,

[0110] Among them, 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 of 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 a processing unit and a storage unit; technical personnel in this field can understand that the computing device includes a processing unit and a storage unit and does not constitute a limitation on the computing device, and may include more components, or a combination of certain components, or different components. For example, the computing device may also include input and output devices, network access equipment, buses, etc.

[0111] A computer-readable storage medium having a non-volatile program code executable by a processor, wherein when the computer program is executed by the processor, the steps of the simulation calculation method of the urban rail transit traction power supply system provided in this embodiment are implemented in this embodiment; it should be noted that the readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above; the program contained on the readable medium can be transmitted by any appropriate medium, including, but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above. For example, the program code for performing the operation of the present invention can be written in any combination of one or more programming languages, and the programming language includes an object-oriented programming language, such as Java, C++, etc., and also includes a conventional procedural programming language, such as C language or similar programming language. The program code can be executed entirely on the user computing device, partially on the user device, as an independent software package, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0112] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation calculation method for the urban rail transit traction power supply system, characterized in that: The steps include: Constructing a locomotive load model, the locomotive load model includes: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections; Construct a traction power supply system model, equating the actual traction station to a DC power supply, connecting each DC power supply with a transmission line, and obtaining the rated voltage, line length, line unit impedance, and traction station location; It simulates multiple locomotives starting from the depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current values.

2. The simulation calculation method of the urban rail transit traction power supply system according to claim 1 is characterized in that: When obtaining topological structure analysis at different time sections, The train and the traction depot need to be numbered, with the traction depot numbered first and the locomotive numbered last. The positive direction should be the same as the locomotive running direction, that is, from up to down. The train positions and traction depot positions are sorted and numbered in sequence, and the sorted and numbered trains and traction depots are regarded as nodes, and the adjacent nodes are branches, and the matrix [Loc] is obtained. m×3 , where the number of rows is m, i.e. the number of branches, and the number of the front and back nodes of each branch are respectively stored in [Loc] m×3 The first and second columns of the , and the third column are the distance difference between the front and rear nodes, which is the length of the branch; Then, the node admittance matrix is ​​established according to the relative position of each node and the unit impedance of the contact network.

3. The simulation calculation method of the urban rail transit traction power supply system according to claim 1 is characterized in that: The power flow calculation of the DC traction network is solved by using the Newton-Raphson iteration method.

4. The simulation calculation method of the urban rail transit traction power supply system according to claim 3 is characterized in that: During the power flow calculation process of the DC traction network, locomotives that are 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. After that, the voltage value of the traction station input in each section is the calculation result of the previous section, and the iterative solution is performed. Through iteration, the voltage value of each node, branch current, and node power can be solved.

5. The simulation calculation method of the urban rail transit traction power supply system according to claim 4 is characterized in that: According to the voltage values ​​of the front and rear nodes of each branch, the branch voltage is calculated, and the branch voltage is multiplied by the admittance of the corresponding branch to get the branch current. Then, the feeder current value of each traction station is selected from the branch current according to the numbers of the front and rear nodes, and the feeder current of each station is arranged in the order of the upstream left feeder current, the upstream right feeder current, the downstream right feeder current and the downstream left feeder current.

6. The simulation calculation method of the urban rail transit traction power supply system according to claim 2 is characterized in that: During topological structure analysis, [Loc] m×3 It will be updated once every calculation cycle to ensure that it is consistent with the real-time dynamic process of the locomotive.

7. The simulation calculation method of the urban rail transit traction power supply system according to claim 4 is characterized in that: When obtaining the speed, acceleration, position and power values ​​of the train during the movement process, 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 the constant torque state, constant power state, inertia 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, presenting a hyperbolic relationship. In the natural characteristic state, the traction force is inversely proportional to the square of the speed. In the inertia 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 is a negative value.

8. A simulation computing device for a traction power supply system of urban rail transit, characterized in that: include: The locomotive load model building module is used to build a locomotive load model, which includes: obtaining the speed, acceleration, position and power value of the train during the movement process, establishing a locomotive operation status information table of a unified time section, combining the locomotive position with the position of the traction station in the line, and obtaining a topological structure analysis of different time sections; The traction power supply system model building module is used to build the traction power supply system model, which equates the actual traction station to a DC power supply, connects each DC power supply with a transmission line, and obtains the rated voltage, line length, line unit impedance, and traction station location; The voltage and current acquisition module is used to simulate multiple locomotives starting from the vehicle depot and running from the beginning to the end of the line. The power and position values ​​of each locomotive are obtained according to the locomotive load model, 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 locomotive, the bus voltage of the traction station and the feeder current value.

9. A computing device, characterized in that: include: one or more processing units; A storage unit for storing 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 execute the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a non-volatile program code executable by a processor, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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