CN107391814B - A Traction Network-EMU Modeling Method for High-speed Railway Stations - Google Patents

Abstract

The invention discloses a method for modeling a traction network and an EMU for a high-speed railway station. And the equivalent circuit model of the traction substation; based on the built traction network and EMU model, according to the design and simulation of the EMU’s different operating conditions in the station, the transient changes of electrical parameters of the corresponding operating conditions are obtained. By establishing the equivalent circuit model of the traction network-EMU in the high-speed railway station, the present invention can more accurately simulate and simulate the running conditions of the EMU in the high-speed railway station, thereby facilitating testing and optimizing the operating parameters.

Description

A Traction Network-EMU Modeling Method for High-speed Railway Stations

technical field

The invention relates to the technical field of safe operation of electrified railway EMUs, in particular to a traction network-EMU modeling method for high-speed railway stations.

Background technique

With the vigorous development of high-speed railways, the safe and stable operation of EMUs has increasingly become the focus of attention. Many electromagnetic transient phenomena during the operation of the EMU occur in the high-speed railway station yard, such as the EMU bow-raising condition, the bow-lowering condition, and the backflow cut-off point. When the EMU is in the lifting bow condition, the voltage of the car body will suddenly rise sharply, and an arc between the pantograph and grid will also occur. If the protective grounding method is unreasonable, it will cause the fluctuation of the car body voltage and the uneven distribution of the electric potential of each section of the car body. .

The car body is not only the reference ground potential of the on-board electrical and electronic equipment, but also the leakage channel for the protection grounding. The fluctuation of the car body voltage can easily interfere with the weak current equipment on the car, break down the sensor, and bring security risks to the train operation. When the wheelset of the EMU passes the backflow cut-off point, the instantaneous connection and instantaneous cut-off of current may occur, which may cause high-intensity arcing. On-site investigation, the arc will cause the burning of the rail head at the insulation section of the track circuit, shorten the service life of the rail, and affect the safety of train operation, and it has been found many times in domestic high-speed railway stations.

Because it is very difficult to organize on-site tests under the operating conditions of high-speed railways, and it is not feasible to directly test the overvoltage of the car body and the current in the rails, the simulation model analysis method is used to obtain the transient changes of electrical parameters in the operating conditions of the EMU. important means. The traction network model in the existing vehicle-network coupling model is basically established for the common power supply interval. In order to more accurately simulate the operating conditions of the EMU in the high-speed railway station, a detailed model is established according to the characteristics of the traction network of the high-speed railway station. The station yard traction network - EMU model is very necessary.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a traction network-EMU modeling method for high-speed railway station yard, using MATLAB/Simulink software to build a detailed high-speed railway station yard traction network-EMU simulation model, simulating the high-speed railway station yard. The operating conditions of the EMU are convenient to test and optimize the operating parameters.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A method for modeling a traction network and an EMU for a high-speed railway station yard, comprising the following steps:

Step 1: build an EMU equivalent circuit model, the EMU equivalent circuit model includes the EMU high-voltage cable, the EMU body, the EMU working grounding system and the EMU protective grounding system;

Step 2: Build the equivalent circuit model of the traction network, the rails and the traction substation. The traction network adopts the full-parallel autotransformer power supply mode on the main line of the high-speed railway station, and the corresponding contact lines and steel rails are added to the side line;

The chain circuit model is used to simulate the traction network model; according to the locations of traction substations, stations, EMUs, autotransformers and sub-stations, the traction network model is divided into multiple serial sub-network models; for each sub-network model , using the π-type network to reflect the inductive coupling and capacitive coupling of each conductor;

Step 3: Calculate the parameters of each part of the station yard traction network model, combine the multi-conductor transmission line theory, and determine the inductive and capacitive coupling parameters of each conductor by enumerating the impedance and admittance matrix, matrix reduction and matrix transformation;

Step 4: Based on the built traction network and EMU model, design and simulate the operating conditions of the EMU, and obtain the transient changes of electrical parameters of the corresponding operating conditions.

Further, the step 3 is specifically: by merging the contact wire and the bearing cable into a catenary, and merging the two parallel rails into one rail to achieve matrix reduction;

In the calculation of impedance parameters, an n×n impedance matrix is listed, namely:

Among them, u _i refers to the voltage drop across the conductor per unit length, and i _i refers to the current flowing through the conductor; the self-impedance Z _ii and Mutual impedance Z _ij ;

In formula (2), ri is the self-impedance of conductor _i , r _e is the self-impedance of the ground, D _g is the equivalent depth of the ground, σ is the conductivity of the ground, f is the frequency; R _i is the equivalent radius of the conductor i, d _ij is the distance between conductor i and conductor j;

Assuming that the currents in the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are i _T , i _C , i _J , i _R , i _A , i _B , and the corresponding voltages are u _T , u _C , u _J , u _R , u _A , u _B , combined with the actual situation of the traction network, u _C = u _J = u _T , u _R = u _A +u _B , i _T = i _C +i _J and i _R = i _A +i _B is used to reduce the order of the impedance matrix shown in equation (1);

In the capacitance parameter calculation, first write the potential coefficient matrix, and then invert the potential coefficient matrix to obtain the wire distributed capacitance coefficient matrix; the n×n potential coefficient matrix is listed, namely:

u _i is the voltage drop per unit length of conductor i, q _i is the charge per unit length of conductor i, the self-potential coefficient P _ii of conductor i and the mutual potential coefficient P _ij of conductor i and conductor j are calculated according to formula (4);

In formula (4), ε ₀ is the air permittivity, R _i is the equivalent radius of conductor _i , hi is the height between conductor i and the ground, d _ij is the distance between conductor i and conductor j, and D _ij is conductor i and the mirror image distance between conductor j; assuming that the electric charge of the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are q _T , q _C , q _J , q _R , q _A , q _B , the corresponding conductors are The voltages are u _T , u _C , u _J , u _R , u _A , u _B , according to q _T = q _C + q _J , q _R = q _A + q _B , u _C = u _J = u _T and u _R =u _A +u _B The potential coefficient matrix of formula (4) is reduced in order.

Compared with the prior art, the beneficial effect of the present invention is that a detailed high-speed railway station yard traction network-EMU simulation model is built on the MATLAB/Simulink platform, and the method can establish a detailed high-speed railway station yard traction network-EMU equivalent circuit by establishing a detailed equivalent circuit. The model can more accurately simulate and simulate the operating conditions of the EMU in the high-speed railway station, so as to facilitate testing and optimize operating parameters.

Description of drawings

Figure 1 is a schematic diagram of the model of each part of the EMU.

Figure 2 is a schematic diagram of the distribution of the main line and side line of the station and the corresponding power supply mode of the traction network.

Figure 3 is a schematic diagram of the chain model of the traction network in the common road section and the station road section.

Figure 4 is a schematic diagram of the side line of Wuxi Station.

Figure 5 is a schematic diagram of the electrical structure of the CRH380BL EMU.

Figure 6 is a schematic diagram of the station yard traction network and the EMU model.

Figure 7 shows the change of electrical parameters in the complete process of the wheelset passing through the cut-off point of the rail insulation section.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Step 1: Analyze the electrical structure of the EMU and build the equivalent circuit model of the EMU. The specific analysis is as follows: when the EMU is in normal operation, the pantograph introduces the catenary voltage into the high-voltage cable located on the roof and transmits it to the on-board transformer. On the primary side of the on-board transformer, the traction current is brushed into the ground through the working grounding system of the EMU, the axle grounding terminal box and the grounding carbon. In addition to the working grounding, there are protective groundings on some vehicle bodies. Based on the above electrical principles and structures, the established EMU equivalent circuit model is mainly composed of four parts: the EMU high-voltage cable, the EMU body, the EMU working grounding system and the EMU protective grounding system. The model of each part is shown in Figure 1. . According to the structural characteristics of the specific models studied, each module is assembled, which mainly considers the number of car bodies, working grounding positions, protective grounding positions, and protective grounding methods of different models. The model parameters of different types of EMUs depend on the specific test results.

Step 2: Analyze the structural characteristics of the station yard traction network, build the equivalent circuit model of the traction network, rails and traction substations. The traction network adopts a fully parallel autotransformer (AT) power supply mode on the main line of the high-speed railway station Corresponding contact wires and rails were added, as shown in Figure 2. For the traction net model, since the wires are parallel to each other, a chain circuit model is used to simulate it. According to the location of traction substations, stations, EMUs, auto-transformers (ATS) and sub-stations (SPS), the traction network model can be divided into multiple serial sub-network models. At the same time, there are many components in these sub-network models connecting different wires, including traction substations, EMUs, ATS, SPS, transverse connecting lines, etc. For each sub-network model, a π-type network is used to reflect the inductive and capacitive coupling of each conductor.

In the traction network chain circuit model on the common road section as shown in Figure 3, Tin1, Rin1, Pin1, Fin1 and Tin2, Rin2, Pin2, Fin2 respectively represent the catenary, rail, protection line and positive feeder in the up and down direction The input ports of Tout1, Rout1, Pout1, Fout1 and Tout2, Rout2, Pout2, and Fout2 represent the output ports of the catenary, rail, protection line, and positive feeder in the upstream and downstream directions, respectively. In the chain circuit model of the station traction network shown in Fig. 3, compared with the traction network model of the ordinary power supply section, additional catenary and rails are added in the downward direction of the side line. Among them, Tin3, Rin3 and Tin4, Rin4 represent the corresponding input ports respectively; Tout3, Rout3, Tout4, Rout4 represent the corresponding wire output ports.

Step 3: Calculate the parameters of each part of the station yard traction network model, combine the multi-conductor transmission line theory, and determine the inductive and capacitive coupling parameters of each conductor by enumerating the impedance and admittance matrices, matrix reduction and matrix transformation. Matrix reduction is achieved by merging the contact wires and load-bearing cables into a catenary and merging two parallel rails into a single rail.

In the calculation of impedance parameters, first formula (1) lists the n×n impedance matrix, where _ui refers to the voltage drop across the conductor of unit length, and _ii refers to the current flowing through the conductor. The self-impedance Z _ii and mutual impedance Z _ij of the pulling conductor in equation (1) are determined using the widely used Carson formula.

In formula (2), ri is the self-impedance of conductor _i ; r _e is the self-impedance of the ground, which is generally 0.049Ω/km at power frequency; D _g is the equivalent depth of the ground, generally 930m, and the corresponding ground conductance The rate σ=10 ^-4 /(Ω·cm); f is the frequency; R _i is the equivalent radius of conductor i; d _ij is the distance between conductor i and conductor j.

Assuming that the currents in the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are i _T , i _C , i _J , i _R , i _A , i _B , respectively, and the voltages of the corresponding conductors are u _T , u _C , u _J , u _R , u _A , u _B , combined with the actual situation of the traction network, u _C = u _J = u _T , u _R = u _A +u _B , i _T = i _C +i _J and i _R = i _A +i _B can be considered to reduce the order of the impedance matrix shown in equation (1).

In the calculation of capacitance parameters, first write the potential coefficient matrix, and then invert the potential coefficient matrix to obtain the wire distributed capacitance coefficient matrix. Formula (3) lists the potential coefficient matrix of n×n, _ui is the voltage drop per unit length of conductor i, and q _i is the electric quantity per unit length of conductor i. The self-potential coefficient P _ii of conductor i and the mutual potential coefficient P _ij of conductor i and conductor j are calculated according to formula (4).

In formula (4), ε ₀ is the dielectric constant of air, that is, 8.854×10-9 (F/km); R _i is the equivalent radius of conductor _i ; hi is the height between conductor i and the ground; d _ij is the conductor i The distance between i and conductor j; D _ij is the mirror image distance between conductor i and conductor j. Similarly, assuming that the electric quantities of the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are q _T , q _C , q _J , q _R , q _A , q _B , the voltages of the corresponding conductors are u _T , u _C ,u _J ,u _R ,u _A ,u _B , according to q _T =q _C +q _J ,q _R =q _A +q _B ,u _C =u _J =u _T and u _R =u _A +u _B Reduce the order of the potential coefficient matrix of formula (4).

Step 4: Based on the constructed station yard traction network and EMU model, the operating conditions of the EMU in the station can be simulated and obtained, and the transient changes of electrical parameters can be obtained.

The method and effect of the present invention will be described below through specific examples.

The Beijing-Shanghai high-speed railway Wuxi station and CRH380BL EMU are selected as examples to carry out the case study. The schematic diagram of Wuxi station station and yard is shown in Figure 4, and the electrical structure model of CRH380BL EMU is shown in Figure 5. The traction network built in MATLAB/Simulink - The EMU model is shown in Figure 6. According to the grounding position of the EMU and the length of the station line, the station yard traction network chain model is divided into multiple serial sub-models.

The method in the example of the present invention is verified by selecting the process that the drain wheel pair of the CRH380BL EMU located in the No. 15 car body passes through the insulating section of the cut-off point in the station. Assuming that the EMU exits the station from the left to right from the 3G track, Figure 4 shows the length of each section of the station and the location of the cut-off point of the 3G track insulation. Figure 7 is the simulation of the change of electrical parameters in the complete process of the wheelset passing through the cut-off point of the rail insulation node. As can be seen from the attached figure, i is 0 and u is a sine wave before the wheelset bridges the rail insulation section at the backflow cut-off point; then the wheelset starts to bridge the rail insulation section at the backflow cut-off point at 0.004s and divides a part of the flow Pulling current, u changes to almost zero at this time. The arc appeared at the moment when the wheelset left the rail on the left side of the cut-off point at 0.0045s, and lasted for 0.005s. Due to the arc, the current and voltage were distorted.

After the arc is extinguished, the voltage and current gradually return to sine waves, i represents the traction backflow from the 15TB bleeder pair to the shunt, and flows back to the traction substation from the right side of the cut-off point. The 2TB, 7TB, and 10TB bleeder pairs shunted Traction return flows back to the traction substation from the left of the cut-off point. It can be found through analysis that the simulation model established by the present invention can effectively analyze the change of electrical parameters when the wheelset of the EMU passes the cut-off point of the rail insulation section.

Claims (1)

1. a traction network for high-speed railway station yard-EMU modeling method, is characterized in that, comprises the following steps: Step 1: build an EMU equivalent circuit model, the EMU equivalent circuit model includes the EMU high-voltage cable, the EMU body, the EMU working grounding system and the EMU protective grounding system; Step 2: Build the equivalent circuit model of the traction network, the rails and the traction substation. The traction network adopts the full-parallel autotransformer power supply mode on the main line of the high-speed railway station, and the corresponding contact lines and steel rails are added to the side line; The chain circuit model is used to simulate the traction network model; according to the locations of traction substations, stations, EMUs, autotransformers and sub-stations, the traction network model is divided into multiple serial sub-network models; for each sub-network model , using the π-type network to reflect the inductive coupling and capacitive coupling of each conductor; Step 3: Calculate the parameters of each part of the station yard traction network model, combine the multi-conductor transmission line theory, and determine the inductive and capacitive coupling parameters of each conductor by enumerating the impedance and admittance matrix, matrix reduction and matrix transformation; Step 4: Based on the built traction network and the EMU model, design and simulate according to the operating conditions of the EMU, and obtain the transient changes of electrical parameters of the corresponding operating conditions; The step 3 is specifically: by merging the contact wire and the bearing cable into a catenary, and merging two parallel rails into one rail to achieve matrix reduction; In the calculation of impedance parameters, an n×n impedance matrix is listed, namely:

Among them, u _i refers to the voltage drop across the conductor per unit length, and i _i refers to the current flowing through the conductor; the self-impedance Z _ii and Mutual impedance Z _ij ;

In formula (2), ri is the self-impedance of conductor _i , r _e is the self-impedance of the ground, D _g is the equivalent depth of the ground, σ is the conductivity of the ground, f is the frequency; R _i is the equivalent radius of the conductor i, d _ij is the distance between conductor i and conductor j; Assuming that the currents in the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are i _T , i _C , i _J , i _R , i _A , i _B , and the corresponding voltages are u _T , u _C , u _J , u _R , u _A , u _B , combined with the actual situation of the traction network, u _C = u _J = u _T , u _R = u _A +u _B , i _T = i _C +i _J and i _R = i _A +i _B is used to reduce the order of the impedance matrix shown in equation (1); In the capacitance parameter calculation, first write the potential coefficient matrix, and then invert the potential coefficient matrix to obtain the wire distributed capacitance coefficient matrix; the n×n potential coefficient matrix is listed, namely:

u _i is the voltage drop per unit length of conductor i, q _i is the charge per unit length of conductor i, the self-potential coefficient P _ii of conductor i and the mutual potential coefficient P _ij of conductor i and conductor j are calculated according to formula (4);

In formula (4), ε ₀ is the air permittivity, R _i is the equivalent radius of conductor _i , hi is the height between conductor i and the ground, d _ij is the distance between conductor i and conductor j, and D _ij is conductor i and the mirror image distance between conductor j; assuming that the electric charge of the catenary, the contact wire, the load-bearing cable, the combined rail and the two parallel rails are q _T , q _C , q _J , q _R , q _A , q _B , the corresponding conductors are The voltages are u _T , u _C , u _J , u _R , u _A , u _B , according to q _T = q _C + q _J , q _R = q _A + q _B , u _C = u _J = u _T and u _R =u _A +u _B The potential coefficient matrix of formula (4) is reduced in order.

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