Urban rail transit metro vehicle pantograph-catenary arc radiation emi emission simulation platform

Abstract

This invention discloses a simulation platform for EMI emission from pantograph-catenary arc discharge in urban rail transit metro vehicles. The platform includes a microwave anechoic chamber containing an equivalent impedance box assembly. This assembly is sequentially connected to an equivalent impedance box for power supply cables, an equivalent impedance box for the pantograph-catenary system, an equivalent impedance box for onboard line reactors, a parallel combination of equivalent impedance boxes for onboard filter capacitors and onboard converter modules, an equivalent impedance box for wheelsets, and an equivalent impedance box for return lines. One end of the equivalent impedance box assembly is connected to an EMI signal transmitting box located at the A side of the traction substation outside the microwave anechoic chamber, and the other end is connected to an EMI signal transmitting box located at the B side of the traction substation outside the microwave anechoic chamber. Using this platform, the emission environment of radiated EMI generated by arc discharge when the pantograph-catenary system is offline in a metro vehicle can be accurately simulated.

Description

Technical Field

[0001] This invention belongs to the field of urban rail transit and electromagnetic compatibility technology, and relates to an EMI emission simulation platform for pantograph-catenary arc radiation of urban rail transit subway vehicles. Background Technology

[0002] With the rapid development of urban rail transit, research on the impact of electromagnetic radiation on the surrounding environment and onboard equipment of trains is becoming increasingly important. Among these, electromagnetic interference generated by the arc discharge phenomenon between the pantograph and the overhead contact line during pantograph raising and lowering significantly affects the normal operation of onboard equipment and commonly used electronic devices in subway vehicles. However, the EMI characteristics of pantograph-catenary offline arc radiation and its impact mechanism on electronic equipment are still under investigation. Frequent replacement of electronic equipment is required for repeated testing under pantograph-catenary offline arc radiation EMI emission conditions. However, field testing requires continuous or fixed-requirement raising and lowering of the pantograph, which is difficult to meet in practice. Furthermore, repeated field testing suffers from drawbacks such as difficulty in coordinating testing time, high labor and time costs, and inability to guarantee the safety factor of onboard equipment. Therefore, it is necessary to design a convenient simulation platform that can accurately simulate the arc radiation EMI emission of subway vehicles when the pantograph and overhead contact line are offline, to easily evaluate and verify the operating status of different electronic devices under the pantograph-catenary offline arc radiation EMI emission environment, while reducing testing time and labor costs. Summary of the Invention

[0003] The purpose of this invention is to provide a simulation platform for EMI emission from pantograph-catenary arc discharge in urban rail transit metro vehicles. This platform can accurately simulate the emission environment of EMI generated by arc discharge when the pantograph-catenary is offline in metro vehicles.

[0004] The technical solution adopted in this invention is an EMI emission simulation platform for pantograph-catenary arc radiation of urban rail transit subway vehicles, including a microwave anechoic chamber. The microwave anechoic chamber is equipped with an equivalent impedance box assembly, which is sequentially connected to the power supply cable equivalent impedance box, the pantograph-catenary system equivalent impedance box, the on-board line reactor equivalent impedance box, the on-board filter capacitor equivalent impedance box and the on-board converter module equivalent impedance box in parallel combination, the wheelset part equivalent impedance box and the return line equivalent impedance box. One end of the equivalent impedance box assembly is connected to the EMI signal transmitting box on the A side of the traction substation located outside the microwave anechoic chamber, and the other end of the equivalent impedance box assembly is connected to the EMI signal transmitting box on the B side of the traction substation located outside the microwave anechoic chamber.

[0005] The invention is further characterized by:

[0006] The equivalent impedance box assembly includes several power supply cable equivalent impedance boxes connected in series. Each power supply cable equivalent impedance box contains a power supply cable equivalent capacitance. The power supply cable equivalent capacitance and the power supply cable equivalent inductance are connected in parallel and then connected in series with the power supply cable equivalent resistance. A power supply cable side timer switch is provided on the connection line between each power supply cable equivalent impedance box and the pantograph-catenary system equivalent impedance box.

[0007] The vehicle-mounted equivalent impedance box assembly includes a vehicle-mounted filter capacitor equivalent impedance box and a vehicle-mounted converter module equivalent impedance box connected in parallel. The vehicle-mounted filter capacitor equivalent impedance box contains the vehicle-mounted filter capacitor parasitic inductance, the vehicle-mounted filter capacitor equivalent resistance, and the vehicle-mounted filter capacitor capacitance connected in series. The vehicle-mounted converter module equivalent impedance box contains the vehicle-mounted converter unit equivalent inductance, which is connected in series with the vehicle-mounted converter unit equivalent capacitance and the vehicle-mounted converter unit equivalent resistance connected in parallel.

[0008] The return line equivalent impedance box assembly includes several return line equivalent impedance boxes connected in series. Each return line equivalent impedance box contains a return line equivalent resistance, which is connected in series with the return line equivalent capacitance and return line equivalent inductance connected in parallel.

[0009] The connection line between the wheelset section equivalent impedance box and each return line equivalent impedance box is equipped with a return line side timer switch.

[0010] The EMI signal transmitter box on the A side of the traction substation contains a radio frequency signal generator and a power amplifier connected together on the A side of the traction substation; the EMI signal transmitter box on the B side of the traction substation contains a radio frequency signal generator and a power amplifier on the B side of the traction substation.

[0011] The design method of the EMI emission simulation platform for pantograph-catenary arc radiation of urban rail transit metro vehicles includes the multi-module design of the equivalent impedance box for power supply cables, the multi-module design of the equivalent impedance box for return lines, and the layout design between the various equivalent impedance boxes.

[0012] The multi-module design process of the power supply cable equivalent impedance box is as follows:

[0013] Let the distance between two adjacent traction substations be D. Divide the line equivalent impedance box into D / k power supply cable equivalent impedance box modules with unit length k. As the subway vehicle moves, the impedance change on the power supply cable is controlled by timed switches on the power supply cable side between each submodule. The timers are numbered sequentially from 1 to (D / k), and their direction is from traction substation A to traction substation B, i.e., from left to right. The equivalent resistance value R of the power supply cable in each power supply cable equivalent impedance box module is...gd The inductance value L of the equivalent inductance of the power supply cable gd The capacitance value C of the equivalent capacitance of the power supply cable. gd The activation time T of each timer switch on the power supply cable side n and the duration T of the timer switch being turned on on each power supply cable side ong The values ​​of are shown in the following formula:

[0014]

[0015]

[0016]

[0017]

[0018]

[0019] Where ε1 is the dielectric constant of air; σ1 is the conductivity of the power supply cable; μ g d is the magnetic permeability of the power supply cable; α is the distance between two adjacent power transmission cables in meters; h is the radius of the power supply cable in meters. g f1 represents the height of the power supply cable above ground, in meters (m); f1 represents the frequency of the current flowing through the power supply cable, in Hz. denoted as skin depth of the cable in meters (m); D is the distance between two adjacent traction substations in meters (m); k is the scaling factor; v is the train's constant speed in km / h; and n is the number of equivalent impedance boxes for the power supply cable.

[0020] The multi-module design process of the return line equivalent impedance box is as follows:

[0021] Let the distance between two adjacent traction substations be D. Divide the line equivalent impedance box into D / u return line equivalent impedance box modules with unit length u. As the train moves, the impedance change on the return line is controlled by a timer switch on the return line side between each submodule. The timer switches close and open when the set time is reached. The timers are numbered sequentially from 1 to (D / u), and the direction is from traction substation A to traction substation B. The resistance value R of the equivalent resistance of the return line in each return line equivalent impedance box module is... hl The inductance value L of the equivalent inductance of the return line. hl The capacitance value C of the equivalent capacitance of the return line. hl The activation time T of the timer switch on each return line side j and the duration T of the timer switch being turned on on each return line side onh The values ​​of are shown in the following formula:

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] Where ρ is the resistivity of the conductor inside the rail, in Ω·m; D is the distance between two adjacent traction substations, in meters; b is the distance between the axis of the equivalent cylindrical conductor of the rail and the center of the rail, in meters; r i =L / 2π is the radius of the equivalent cylindrical conductor of the rail, in meters; L is the circumference of the rail's cross-section, in meters; h r The height of the equivalent cylindrical conductor of the rail above the ground is expressed in meters (m); μ r σ0 is the relative permeability of the rail, in H / m; μ0 is the permeability of free space, in H / m; ε0 is the permittivity of free space, in F / m; f2 is the frequency of the current flowing through the return line, in Hz; σ2 is the conductivity of the rail, in S / m. denoted as the skin depth of the conductor, in meters; u is the return line proportion factor; j is the number of equivalent impedance box modules for the return line.

[0028] The inter-station design of each equivalent impedance enclosure consists of an EMI signal transmitting box on the A side of the traction substation / EMI signal transmitting box on the B side of the traction substation, an equivalent impedance box for power supply cables, an equivalent impedance box for the pantograph-catenary system, an equivalent impedance box for on-board line reactors, an equivalent impedance box for on-board filter capacitors, an equivalent impedance box for on-board converter modules, an equivalent impedance box for wheelsets, an equivalent impedance box for return lines, and an EMI shielding box on the A side of the traction substation, forming a loop antenna that radiates EMI to the outside. The offline arc radiation field strength E of the pantograph-catenary system was measured within the constructed platform. p The measured radiated electric field intensity E emitted outward by the offline arc of the pantograph-catenary system s and the measured area S of the loop antenna s The following requirements must be met:

[0029]

[0030]

[0031] S s =h×D c (13);

[0032] Among them, S s S represents the area of ​​a single loop antenna formed by the interference loop in the actual test;p η is the area of ​​a single loop antenna formed by the interference loop in the constructed platform; I0 is the air wave impedance; k is the amplitude of the interference current; b =2π / λ is the wave number; λ is the wavelength; r is the distance between the measured point and the center of the loop antenna, in meters; θ is the angle between the measured point and the vertical axis of the antenna; h is the height of the subway vehicle considering the pantograph-catenary system, in meters; D c The distance between the subway car and the traction substation is expressed in meters (m); r s r is the distance between the measured point and the center of the loop antenna in actual testing, in meters (m). p The distance between the test point and the center of the loop antenna in the constructed platform is expressed in meters (m).

[0033] The beneficial effects of this invention are that it proposes a pantograph-catenary arc radiation EMI emission simulation platform, and also provides a method for constructing the designed platform. The designed radiated EMI emission simulation platform is constructed by combining equivalent circuit impedance boxes of different modules in a rail transit train. It can accurately simulate the radiated EMI generated by the arc in the pantograph-catenary system, solving the problem of coordinating testing time for repeated tests of different electronic devices under pantograph-catenary offline arc radiation EMI emission conditions. This reduces testing costs such as labor and time, and improves the safety factor of the equipment. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the design principle of the EMI emission simulation platform for pantograph-catenary electric arc radiation of urban rail transit subway vehicles according to the present invention.

[0035] Figure 2 This is a schematic diagram of the EMI emission simulation platform for pantograph-catenary electric arc radiation of urban rail transit subway vehicles according to the present invention.

[0036] In the diagram, 1. EMI signal transmitter box on side A of traction substation; 2. Power amplifier on side A of traction substation; 3. RF signal generator on side A of traction substation; 4. RF signal generator on side B of traction substation; 5. Power amplifier on side B of traction substation; 6. EMI signal transmitter box on side B of traction substation; 7. Equivalent impedance box for power supply cable; 8. Equivalent impedance box for pantograph-catenary system; 9. Equivalent impedance box for on-board line reactor; 10. Equivalent impedance box for on-board filter capacitor; 11. Equivalent impedance box for on-board converter module; 12. Equivalent impedance box for wheelset section; 13. Equivalent impedance box for return line; 14. Equivalent inductance of power supply cable; 15. Equivalent capacitance of power supply cable; 16. Equivalent resistance of power supply cable; 17. Equivalent inductance of pantograph-catenary system; 18. Pantograph-catenary system. 19. Parasitic capacitance of on-board line reactor; 20. Inductance of on-board line reactor; 21. Equivalent resistance of on-board line reactor; 22. Parasitic inductance of on-board filter capacitor; 23. Equivalent resistance of on-board filter capacitor; 24. Capacitance of on-board filter capacitor; 25. Equivalent inductance of on-board converter unit; 26. Equivalent capacitance of on-board converter unit; 27. Equivalent resistance of on-board converter unit; 28. Equivalent resistance of wheelset section; 29. ​​Equivalent capacitance of wheelset section; 30. Equivalent capacitance of return line; 31. Equivalent inductance of return line; 32. Equivalent resistance of return line; 33. Timer switch on power supply cable side; 34. Timer switch on return line side; 35. Movable and height-adjustable test table and test equipment; 36. Microwave anechoic chamber. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] The design principle of the EMI emission simulation platform for pantograph-catenary arc radiation in urban rail transit subway vehicles, as described in this invention, is as follows: Figure 1 As shown, assume that the two traction substations closest to the car body are traction substation A and traction substation B, respectively. The lines connecting to traction substation A are the power supply cable and return line for substation A, respectively, and the lines connecting to traction substation B are the power supply cable and return line for substation B, respectively. An electrical connection is established between the subway car and the power supply cable via a pantograph. The internal traction system of the subway car mainly includes line reactors, filter capacitor units, and on-board converter units.

[0039] Figure 1This describes how, when an arc occurs due to pantograph-catenary disconnection at the pantograph, taking the traction substation A side as an example, the resulting interference current flows through the vehicle body shell—inside the vehicle's wiring reactor—filter capacitor and on-board converter—wheels and wheelsets—return line on substation A side—traction substation A—power supply cable on substation A side, and then returns to the pantograph, forming a complete interference loop. Similarly, a complete interference loop will also form on the traction substation B side. Both interference loops act simultaneously, radiating electromagnetic interference into the external environment. The interference current signal generated by the pantograph-catenary disconnection arc can be measured by connecting a current probe to an EMI receiver via an attenuator.

[0040] Based on the above Figure 1 Based on the design principles, this invention presents a simulation platform for EMI emission from pantograph-catenary arc radiation in urban rail transit subway vehicles. The structure is as follows: Figure 2 As shown, Figure 1 and Figure 2 The correspondence between the components is as follows: Figure 1 The interference current signal generated by the offline arc of the pantograph-catenary circuit is measured by the current probe connected to the EMI receiver via an attenuator. Figure 2 The combination of the radio frequency signal generator 3 on the A side of the traction substation and the power amplifier 2 on the A side of the traction substation also corresponds to the combination of the radio frequency signal generator 4 on the B side of the traction substation and the power amplifier 5 on the B side of the traction substation. Both serve as signal sources to emit interference signals generated by the offline arc of the pantograph and the catenary. Figure 1 The power supply cables on side A of the traction substation and the power supply cables on side B of the traction substation correspond to each other. Figure 2 Equivalent impedance box for power supply cables 7; Figure 1 Pantograph correspondence Figure 2 Equivalent impedance box 8 for the central bow wire mesh system; Figure 1 Corresponding to the medium-voltage line reactor Figure 2 9. Equivalent impedance box for CRRC-mounted line reactor; Figure 1 The corresponding filter capacitor unit Figure 2 Equivalent impedance box for vehicle-mounted filter capacitors 10; Figure 1 Corresponding to CRRC on-board converter unit Figure 2 CRRC on-board converter module equivalent impedance box 11; Figure 1 Middle wheel correspondence Figure 2 Equivalent impedance box 12 for the middle wheelset section; Figure 1 Corresponding return lines on side A and side B of the substation Figure 2 Equivalent impedance box for medium return line 13.

[0041] Example 1

[0042] This invention relates to an EMI emission simulation platform for pantograph-catenary arc radiation in urban rail transit metro vehicles, comprising: an EMI signal emission box 1 for the A-side of the traction substation, composed of a radio frequency signal generator 3 and a power amplifier 2 on the A-side of the traction substation; an EMI signal emission box 6 for the B-side of the traction substation, composed of a radio frequency signal generator 4 and a power amplifier 5 on the B-side of the traction substation; an equivalent impedance box 7 for the power supply cable, composed of the equivalent capacitance 15 and equivalent inductance 14 of the power supply cable connected in parallel and the equivalent resistance 16 of the power supply cable connected in series; an equivalent impedance box 8 for the pantograph-catenary system, composed of the equivalent inductance 17 and equivalent resistance 18 of the pantograph-catenary system connected in series; and an on-board line reactor, composed of the inductance 20 and equivalent resistance 21 of the on-board line reactor connected in series and the parasitic capacitance 19 of the on-board line reactor. The system includes an equivalent impedance box 9, an equivalent impedance box 10 for the vehicle filter capacitor (composed of the parasitic inductance 22, equivalent resistance 23, and capacitance 24 connected in series), an equivalent impedance box 11 for the vehicle converter module (composed of the equivalent capacitance 26 and equivalent resistance 27 of the vehicle converter unit connected in parallel and connected in series with the equivalent inductance 25 of the vehicle converter unit), an equivalent impedance box 12 for the wheelset section (composed of the equivalent resistance 28 and equivalent capacitance 29 connected in series), and an equivalent impedance box 13 for the return line (composed of the equivalent capacitance 30 and equivalent inductance 31 connected in parallel and connected in series with the equivalent resistance 32 of the return line). It also includes a power supply cable side timer switch 33, a return line side timer switch 34, a microwave anechoic chamber 36, a movable and liftable test table, and the device under test 35.

[0043] The working principle of the EMI emission simulation platform for pantograph-catenary arc radiation of urban rail transit metro vehicles of the present invention is as follows: outside the designed microwave anechoic chamber, the combination of the RF signal generator 3 on the A side of the traction substation, the RF signal generator 4 on the B side of the traction substation, the power amplifier 2 on the A side of the traction substation, and the EMI signal transmission box 6 on the B side of the traction substation acts as an interference source, injecting the EMI interference signal generated by the pantograph-catenary offline arc into the designed interference circuit. Based on the on / off states of timer switches 33 on different power supply cable sides at different times, high-frequency EMI interference signals flow through the equivalent impedance box 7 of the power supply cable, then through the series combination of the equivalent impedance box 8 of the pantograph-catenary system and the equivalent impedance box 9 of the vehicle-mounted line reactor, then through the parallel combination of the equivalent impedance box 10 of the vehicle-mounted filter capacitor and the equivalent impedance box 11 of the vehicle-mounted converter module, and finally through the equivalent impedance box 12 of the wheelset section. Finally, based on the on / off states of timer switches 34 on different return line sides at different times, a closed loop is formed through the equivalent impedance box 13 of the return line, thus simulating the emission of EMI from offline arc radiation of the pantograph-catenary system. The test platform also includes a movable and liftable test table and test equipment 35 to meet different test conditions for different test equipment.

[0044] To simulate the impedance changes on the line under dynamic train operation, a combination of power supply cable equivalent impedance box 7 and power supply cable side timer switch 33 is used, and a combination of return line equivalent impedance box 13 and return line side timer switch 34 is used. The opening time of each timer switch is calculated according to the train running speed to simulate the dynamic changes of power supply cable impedance and return line impedance. At the same time, based on the principle that the radiated EMI generated by the measured interference circuit is equivalent to the radiated EMI generated by the simulated interference circuit on the platform, the length of the connecting cable between each impedance box in the platform is designed.

[0045] The working process of the EMI emission simulation platform for pantograph-catenary arc radiation in urban rail transit metro vehicles of the present invention is as follows: In the microwave anechoic chamber 36, the radio frequency signal generators 3 and 4 and power amplifiers 2 and 6 in the EMI signal transmission box 1 on the A side of the traction substation and the EMI signal transmission box 6 on the B side of the traction substation are combined to act as interference sources, injecting the EMI interference signal generated by the pantograph-catenary offline arc into the designed interference circuit. The equivalent impedance boxes of the metro vehicle and line include the power supply cable equivalent impedance box 7, the pantograph-catenary system equivalent impedance box 8, the on-board line reactor equivalent impedance box 9, the on-board filter capacitor equivalent impedance box 10, the on-board converter module equivalent impedance box 11, the wheelset part equivalent impedance box 12, and the return line equivalent impedance box 13; at the same time, the simulation platform also includes a power supply cable side timer switch 33 and a return line side timer switch 34 to control the impedance of the power supply cable equivalent impedance box 7 and the return line equivalent impedance box 13 in the platform, and also includes a movable and liftable test table and the test equipment 35.

[0046] The EMI signal transmitter box 1 on the A side of the traction substation includes a radio frequency signal generator 3 on the A side of the traction substation and a power amplifier 2 on the A side of the traction substation.

[0047] The EMI signal transmitter box 6 on the B side of the traction substation includes the radio frequency signal generator 4 on the B side of the traction substation and the power amplifier 5 on the B side of the traction substation.

[0048] The power supply cable equivalent impedance box 7 includes a power supply cable equivalent capacitance 15 and power supply cable equivalent inductance 14 connected in parallel and a power supply cable equivalent resistance 16 connected in series.

[0049] The pantograph-catenary system equivalent impedance box 8 consists of the pantograph-catenary system equivalent inductance 17 and pantograph-catenary system equivalent resistance 18 connected in series.

[0050] The on-board line reactor equivalent impedance box 9 includes the combination of the on-board line reactor inductance 20 and the on-board line reactor equivalent resistance 21 connected in series with the on-board line reactor parasitic capacitance 19.

[0051] The vehicle-mounted filter capacitor equivalent impedance box 10 includes a series combination of the vehicle-mounted filter capacitor parasitic inductance 22, the vehicle-mounted filter capacitor equivalent resistance 23, and the vehicle-mounted filter capacitor capacitance 24.

[0052] The on-board converter module equivalent impedance box 11 includes the on-board converter unit equivalent capacitor 26 and the on-board converter unit equivalent resistor 27 connected in parallel and connected in series with the on-board converter unit equivalent inductance 25.

[0053] The wheelset equivalent impedance box 12 includes a series combination of the wheelset equivalent resistance 28 and the wheelset equivalent capacitance 29.

[0054] The return line equivalent impedance box 13 includes a return line equivalent capacitance 30 and a return line equivalent inductance 31 connected in parallel and a return line equivalent resistance 32 connected in series.

[0055] Example 2

[0056] The parameters of each part of the simulation platform for EMI emission from pantograph-catenary arc radiation in urban rail transit subway vehicles are calculated as follows:

[0057] Step 1, Figure 2 The equivalent resistance of the power supply cable is 16 ohms. gd The calculation.

[0058]

[0059] Where σ1 is the conductivity of the power supply cable; μ gα is the permeability of the power supply cable; f1 is the radius of the power supply cable in meters; D is the frequency of the current flowing through the power supply cable in Hz; k is the distance between two adjacent traction substations in meters; and k is the power supply cable proportion factor. Skin depth of the power supply cable, in meters (m).

[0060] Step 2, Figure 2 The equivalent inductance of the power supply cable is 14 L. gd The calculation.

[0061]

[0062] Where σ1 is the conductivity of the power supply cable; μ g α is the permeability of the power supply cable; f1 is the radius of the power supply cable in meters; D is the frequency of the current flowing through the power supply cable in Hz; k is the distance between two adjacent traction substations in meters; and k is the power supply cable ratio factor.

[0063] Step 3, Figure 2 The equivalent capacitance of the power supply cable is 15 C. gd The calculation.

[0064]

[0065] Where ε1 = 1.00053 is the dielectric constant of air; D is the distance between two adjacent traction substations in meters; k is the power supply cable ratio factor; d is the distance between two adjacent transmission cables in meters; α is the inner diameter of the power supply cable in meters; h g The height of the power supply cable above the ground is expressed in meters (m).

[0066] Step 4, Figure 2 The equivalent inductance of the Zhonggong network system is 17, with an inductance value of L. p The calculation.

[0067] When an arc discharge occurs between the pantograph and the catenary, the inductance value L in the arc discharge channel of the equivalent model is... p The calculation formula is as follows.

[0068]

[0069] Where I av 1 is the average value of the traction current amplitude for the 1st, 5th, and 7th traction discharges, in A; r2 is the radius of the inner conductor of the high-voltage core wire on the roof, in m; v is the uniform running speed of the train, in km / h; t is the duration of the arc discharge, in s.

[0070] Step 5, Figure 2 The equivalent resistance of the Zhonggong network system is 18 resistance values ​​R. p The calculation.

[0071] The resistance value R within the arc discharge channel in the equivalent model p The calculation formula is as follows.

[0072]

[0073] Where δ=0.1MPa·cm 2 ·(s·V 2 ) -1 is a constant; p is the air pressure, which is 101.3 kPa when the temperature T = 20℃; t is the duration of the arc discharge in seconds; i is the traction current in amperes (A); v is the current train speed in m / s; and r3 is the radius of the high-voltage cable on the roof in meters.

[0074] Step 6, Figure 2 Parasitic capacitance of CRRC on-line reactor 19 capacitance value C d The calculation.

[0075]

[0076] Among them, f r L is the corner frequency. d This is the inductance value of the on-board line reactor.

[0077] Step 7, Figure 2 Inductance value L of 20-type on-board line reactor d The calculation can be obtained directly by consulting the design parameters of the subway vehicles.

[0078] Step 8, Figure 2 The equivalent resistance value R of the CRRC on-line reactor is 21. d The calculation.

[0079] Due to manufacturing process limitations, the DC-side line reactor of the traction converter is not an ideal inductor at high frequencies, and it possesses a certain equivalent series resistance R. d .

[0080]

[0081] Among them, f r Where L is the corner frequency, tanδ is the dielectric loss angle, and L is the dielectric loss angle. d This is the inductance value of the on-board line reactor.

[0082] Step 9, Figure 2 The on-board filter capacitor has a capacitance of 24 C. c The calculation.

[0083] This can be obtained directly by consulting the design parameters of the subway vehicles.

[0084] Step 10, Figure 2 Parasitic inductance of the vehicle-mounted filter capacitor 22 inductance value L c The calculation.

[0085]

[0086] Among them, f r C is the corner frequency. c This refers to the capacitance value of the vehicle-mounted filter capacitor.

[0087] Step 11, the equivalent resistance value R of the vehicle-mounted filter capacitor 23. c The calculation.

[0088] Due to manufacturing process limitations, the DC-side support capacitor of the traction converter is not an ideal capacitor at high frequencies, and it possesses a certain equivalent series resistance R. c .

[0089]

[0090] Among them, f r Where is the corner frequency, tanδ is the dielectric loss angle, and C is the dielectric loss angle. c This refers to the capacitance value of the vehicle-mounted filter capacitor.

[0091] Step 12, Figure 2 The equivalent resistance value R of the CRRC on-board converter unit is 27. z The calculation.

[0092] The on-board converter unit comprises two parts: a chopper unit and an inverter unit, which are connected in parallel. The chopper unit contains two power switches connected in parallel, while the inverter unit consists of six power switches connected in series and parallel. Under normal operating conditions, the equivalent resistance R of the on-board converter unit is... z The equivalent resistance R of the chopper unit z_z Equivalent resistance R of inverter unit z_n Composed of parallel elements, wherein the equivalent resistance R of the chopper unit is... z_z The equivalent resistance R of the inverter unit is equal to half the on-resistance of the power switching transistor used in the chopper unit. z_n It is equal to two-thirds of the on-resistance of the power switching transistors used in the inverter unit. The on-resistance of the power switching transistors can be found in the datasheet of the selected power switching transistor.

[0093] Step 13, Figure 2 The equivalent inductance of the CRRC converter unit is 25 L. z The calculation.

[0094] The on-board converter unit comprises two parts: a chopper unit and an inverter unit, which are connected in parallel. The chopper unit contains two power switches connected in parallel, while the inverter unit consists of six power switches connected in series and parallel. At high frequencies, the equivalent inductance L of the on-board converter unit is... z The equivalent inductance L of the chopper unit z_z Equivalent inductance L of inverter unit z_n The components are connected in parallel, with the chopper unit having an equivalent inductance L. z_z The equivalent inductance L of the inverter unit is equal to half the stray inductance of the power switching transistor used in the chopper unit. z_n It is equal to two-thirds of the stray inductance of the power switching transistors used in the inverter unit. The stray inductance of the power switching transistors can be found in the datasheet of the selected power switching transistors.

[0095] Step 14, Figure 2 The equivalent capacitance of the CRRC on-board converter unit is 26 C. z The calculation.

[0096] The on-board converter unit comprises two parts: a chopper unit and an inverter unit, which are connected in parallel. The chopper unit contains two power switches connected in parallel, while the inverter unit consists of six power switches connected in series and parallel. At high frequencies, the bulk capacitance of the power switches serves as the primary path for interference current and is connected in parallel with the switches. Therefore, the equivalent capacitance C of the on-board converter unit is... z The equivalent capacitance C of the chopper unit z_z Equivalent capacitance C of the inverter unit z_n Composed of parallel elements. The equivalent capacitance C of the chopper unit is... z_z The equivalent capacitance C of the inverter unit is twice the equivalent capacitance of the power switching transistors used in the chopper unit. z_n It is equal to three-half of the equivalent capacitance of the power switching transistors used in the inverter unit. The equivalent capacitance of the power switching transistors can be found in the datasheet of the selected power switching transistor.

[0097] Step 15, Figure 2 The equivalent resistance of the middle wheelset is 28 resistance value R. w The calculation.

[0098] Assume a subway car has x wheelsets (consisting of one axle and two identical wheels), and the resistance R of each wheelset is... w The equivalent resistance R of the axle section w1 The equivalent resistance R of the wheel section w2 Composed of series connections. The equivalent resistance R of x wheelsets. w The calculation formula is as follows.

[0099]

[0100] Equivalent resistance of the axle section:

[0101] Where ρ1 is the resistivity of the axle material, l1 is the axle length, and r w1 r is the outer diameter of the axle. w2 This refers to the inner diameter of the axle.

[0102] Equivalent resistance of the wheel section:

[0103] Where ρ2 is the resistivity of the wheel material, l2 is the wheel length, and r w3 r is the outer diameter of the wheel. w4 This refers to the inner diameter of the wheel.

[0104] Step 16, Figure 2 The equivalent capacitance of the middle wheelset is 29 C. w The calculation.

[0105] Assume a subway car has x wheelsets (consisting of one axle and two identical wheels), and the capacitance C of each wheelset is... w The equivalent capacitance C of the axle section w1 The equivalent capacitance C of the wheel section w2 Composed of series connections. The equivalent capacitance C of x wheelsets. w The calculation formula is as follows.

[0106]

[0107] The equivalent capacitance C of the axle section w1 The calculation formula is as follows.

[0108]

[0109] Where ε2 is the dielectric constant of the axle material, l1 is the axle length, and r w1 r is the outer diameter of the axle. w2 This refers to the inner diameter of the axle.

[0110] The equivalent capacitance C of the wheel section w2 The calculation formula is as follows.

[0111]

[0112] Where ε3 is the dielectric constant of the wheel material, l2 is the wheel length, and r w3 r is the outer diameter of the wheel. w4 This refers to the inner diameter of the wheel.

[0113] Step 17, Figure 2 The equivalent resistance of the return circuit is 32 ohms, with a resistance value of R. hl The calculation.

[0114] Because the cross-section of the rail is irregular, shaped like the Chinese character "I," unlike the commonly seen circular conductors, the internal impedance cannot be directly calculated analytically when considering the skin effect. Therefore, based on the principle of area equivalence, the rail is equivalent to a cylindrical conductor. The radius *r* of the equivalent cylindrical conductor of the I-shaped rail is obtained from the cross-sectional area and perimeter of the rail. i The calculation formula is as follows.

[0115]

[0116] Where L is the perimeter of the rail's cross-section.

[0117]

[0118] Where ρ is the resistivity of the rail, in Ω·m; σ2 is the electrical conductivity of the rail, in S / m; The skin depth of the rail, measured in meters (m); r i The radius of the equivalent cylindrical conductor of the I-beam rail, in meters (m); μ r f1 is the relative magnetic permeability of the rail; f2 is the frequency of the current flowing through the return line, in Hz; u is the return line proportion factor.

[0119] Step 18, Figure 2 The equivalent capacitance of the return circuit is 30 C. hl The calculation.

[0120] Because the cross-section of the rail is irregular, shaped like the Chinese character "I," unlike the commonly seen circular conductors, the internal impedance cannot be directly calculated analytically when considering the skin effect. Therefore, based on the principle of area equivalence, the rail is equivalent to a cylindrical conductor. The radius *r* of the equivalent cylindrical conductor of the I-shaped rail is obtained from the cross-sectional area and perimeter of the rail. i The calculation formula is as follows.

[0121]

[0122] Where L is the perimeter of the rail's cross-section.

[0123] Therefore, the overall equivalent capacitance of the two rails can be calculated as follows:

[0124]

[0125] Where C hl1 C is the equivalent capacitance between the two rails; hl2 denoted as , where is the equivalent capacitance of the two rails to the ground; D is the distance between two adjacent traction substations; and u is the return line ratio factor.

[0126] (1) Find the equivalent capacitance between the two rails;

[0127] The capacitance C between the two rails hl1 The calculation formula is as follows.

[0128]

[0129] Where b is the distance between the axis of the equivalent cylindrical conductor of the rail and the center of the rail, in meters; r i ε0 is the radius of the equivalent cylindrical conductor of the rail, in meters; D is the distance between two adjacent traction substations, in meters; ε0 = 8.854187818 × 102 -12 F / m is the vacuum permittivity.

[0130] (2) Find the equivalent capacitance of the two rails to the ground;

[0131] The capacitance to ground of any rail C hl2 The calculation formula is as follows.

[0132]

[0133] Where b is the distance between the axis of the equivalent cylindrical conductor of the rail and the center of the rail, in meters; r i denoted by , where is the radius of the cylindrical conductor of the rail, in meters (m); D is the distance between two adjacent traction substations, in meters (m); h r The equivalent cylindrical conductor height of the rail above the ground is given by ε0, in meters (m); ε0 = 8.8541878 × 10⁻⁶. -12 F / m is the vacuum permittivity.

[0134] Step 19, Figure 2 The equivalent inductance of the return circuit is 31, and the inductance value is L. hl The calculation.

[0135] Because the cross-section of the rail is irregular, shaped like the Chinese character "I," unlike the commonly seen circular conductors, the internal impedance cannot be directly calculated analytically when considering the skin effect. Therefore, based on the principle of area equivalence, the rail is equivalent to a cylindrical conductor. The radius *r* of the equivalent cylindrical conductor of the I-shaped rail is obtained from the cross-sectional area and perimeter of the rail. i The calculation formula is as follows.

[0136]

[0137] Where L is the perimeter of the rail's cross-section.

[0138]

[0139] Where, μ r The relative permeability of the rail conductor material; μ0 = 4π × 10 -7H / m is the vacuum permeability; u is the return line proportion factor; σ² is the rail conductivity, in S / m; r i The radius of the equivalent cylindrical conductor of the I-beam rail, in meters; f1 represents the skin depth of the rail, in meters (m); f2 represents the frequency of the current flowing through the return line, in Hz.

[0140] Example 3

[0141] The present invention relates to a design method for a simulation platform for EMI emission from pantograph-catenary arc radiation in urban rail transit subway vehicles, comprising the following steps:

[0142] Step 1, Figure 2 Multi-module design of equivalent impedance box for power supply cables:

[0143] Let the distance between two adjacent traction substations be D. Divide the line equivalent impedance box into D / k submodules (rounded to the nearest integer) with unit length k. As the subway vehicle moves, the impedance change on the power supply cable is controlled by timed switches between each submodule. The timers close and open at set times. The timers are numbered sequentially from 1 to (D / k), and their direction is from left to right, from traction substation A to traction substation B. The resistor R in each submodule... gd Inductor L gd Capacitor C gd The value of T and the opening time of each timer switch on the power supply cable side n and the duration T of each timer switch being on ong The calculation formula is as follows.

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] Where ε1 = 1.00053 is the dielectric constant of air; σ1 is the conductivity of the power supply cable; μ g d is the magnetic permeability of the power supply cable; α is the distance between two adjacent power transmission cables in meters; h is the radius of the power supply cable in meters. g f1 represents the height of the power supply cable above ground, in meters (m); f1 represents the frequency of the current flowing through the power supply cable, in Hz. denoted as skin depth of the cable in meters (m); D is the distance between two adjacent traction substations in meters (m); k is the power supply cable ratio factor; v is the train's constant speed in km / h; and n is the number of equivalent impedance box modules for the power supply cable.

[0150] Step 2, Figure 2 13-module design of equivalent impedance box for medium return line:

[0151] Let the distance between two adjacent traction substations be D. Divide the line equivalent impedance box into D / u sub-modules (rounded to the nearest integer) with unit length u. As the train moves, the impedance change on the return line is controlled by timed switches between each sub-module. The timers close and open at set times. The timers are numbered sequentially from 1 to (D / u), with the direction from traction substation A to traction substation B. The resistor R in each sub-module... hl Inductor L hl Capacitor C hl The value of T and the opening time of each timer switch on the return line side j and the duration T of each timer switch being on onh The calculation formula is as follows.

[0152]

[0153]

[0154]

[0155]

[0156]

[0157] Where ρ is the resistivity of the conductor inside the rail, in Ω·m; D is the distance between two adjacent traction substations, in meters; b is the distance between the axis of the equivalent cylindrical conductor of the rail and the center of the rail, in meters; r i =L / 2π is the equivalent cylindrical conductor radius of the rail, in meters; L is the perimeter of the rail's cross-section, in meters; h r The height of the equivalent cylindrical conductor of the rail above the ground is expressed in meters (m); μ r The relative permeability of the rail; μ0 = 4π × 10 -7 H / m is the permeability of free space; ε0 = 8.8541878 × 10 - 12 F / m is the vacuum dielectric constant; f2 is the frequency of the current flowing through the return line, in Hz; σ2 is the rail conductivity, in S / m.

[0158] denoted as the skin depth of the rail, in meters; v as the uniform speed of the train, in km / h; u as the return line proportion factor; and j as the number of equivalent impedance box modules for the return line.

[0159] Step 3, Figure 2 The layout design of each equivalent impedance box (including EMI signal transmitter box 1 on the A side of traction substation / EMI signal transmitter box 6 on the B side of traction substation, equivalent impedance box 7 for power supply cables, equivalent impedance box 8 for pantograph-catenary system, equivalent impedance box 9 for on-board line reactor, equivalent impedance box 10 for on-board filter capacitor, equivalent impedance box 11 for on-board converter module, equivalent impedance box 12 for wheelset section, equivalent impedance box 13 for return line, and layout design of EMI signal transmitter box 1 on the A side of traction substation / EMI signal transmitter box 6 on the B side of traction substation).

[0160] During actual testing, the loop antenna, consisting of "traction substation—power supply cable—pantograph—line reactor—filter capacitor unit, on-board converter unit—wheel and return line—traction substation," emitted EMI radiation to the outside world. The measured field strength was recorded as E. s During the testing of the constructed simulation platform, a loop antenna consisting of "EMI signal transmitter box 1 on the A side of traction substation / EMI signal transmitter box 6 on the B side of traction substation - equivalent impedance box for power supply cable 7 - equivalent impedance box for pantograph-catenary system 8 - equivalent impedance box for on-board line reactor 9 - equivalent impedance box for on-board filter capacitor 10 - equivalent impedance box for on-board converter module 11 - equivalent impedance box for wheelset section 12 - equivalent impedance box for return line 13 - EMI signal transmitter box 1 on the A side of traction substation / EMI signal transmitter box 6 on the B side of traction substation" emitted radiated EMI to the outside. The pantograph-catenary offline arc radiation field strength E obtained from the test within the constructed platform was... p The measured radiated electric field intensity E emitted outward by the offline arc of the pantograph-catenary system s and the measured area S of the loop antenna s It satisfies the following three conditions.

[0161]

[0162]

[0163] S s =h×D c

[0164] Where S s S represents the area of ​​a single loop antenna formed by the interference loop in the actual test (assuming the train is located at the midpoint of the track); p The area of ​​a single loop antenna formed by the interference loop in the constructed platform; η = 377Ω is the air wave impedance; I0 is the amplitude of the interference current in A; k b=2π / λ is the wave number; λ is the wavelength; r is the distance between the measured point and the center of the loop antenna; θ is the angle between the measured point and the vertical axis of the antenna; h is the height of the subway vehicle considering the pantograph-catenary system; D c The distance between the subway car and the traction substation; r s r is the distance between the measured point and the center of the loop antenna in actual testing, in meters (m). p The distance between the test point and the center of the loop antenna in the constructed platform is expressed in meters (m).

[0165] To ensure that the constructed platform performs as expected during actual testing, the measured field strength E must be consistent with the actual test results. s The field strength E obtained from testing within the constructed platform p Equal, i.e., E s =E p The area S of a single loop antenna in the constructed platform is obtained. p The calculation formula is as follows.

[0166]

[0167] Where S s The area of ​​a single loop antenna formed by the interference loop in the actual test (assuming the train is located at the midpoint of the track); r s r is the distance between the measured point and the center of the loop antenna in the actual test. p Let r be the distance between the test point and the center of the loop antenna in the constructed platform. Considering the reasonableness of the platform size, let r be... p The initial value is 2m; k b =2π / λ is the wave number.

[0168] Since a single loop antenna in the constructed platform consists of 7 cable segments connecting each impedance box, its layout is designed as a rectangle with a side length ratio of 1.5:4 based on the number of connecting cable segments. The length 'a' of the connecting cable between each impedance box is designed as follows.

[0169]

Claims

1. A simulation platform for EMI emission of arc radiation of a pantograph-catenary system of a metro vehicle, characterized in that: The equivalent impedance box combination includes a plurality of power cable equivalent impedance boxes (7) connected in series. The vehicle-mounted equivalent impedance box combination includes a vehicle-mounted filter capacitor equivalent impedance box (10) and a vehicle-mounted converter module equivalent impedance box (11) connected in parallel. The return line equivalent impedance box combination includes a plurality of return line equivalent impedance boxes (13) connected in series. The return line side timing switch (34) is arranged on the connection line between the wheel set part equivalent impedance box (12) and each return line equivalent impedance box (13). The design method of the city rail transit subway vehicle pantograph-catenary arc radiation EMI emission simulation platform includes multi-module design of the power cable equivalent impedance box (7), multi-module design of the return line equivalent impedance box (13), and layout design between the equivalent impedance boxes. The multi-module design process of the power cable equivalent impedance box (7) is as follows: Take two adjacent traction substation distance for D , the line equivalent impedance box is divided into k unit length, divided into power cable equivalent impedance box (7) sub module, with the movement of the subway vehicle, the impedance changes on the power cable by each sub module power cable side timing switch (33) control, when the power cable side timing switch (33) to the set time when the closing and opening operation, the order of the timer is , the direction is from the traction substation A side to the traction substation B side, that is, from left to right; The resistance value of the power cable equivalent resistance (16) in each power cable equivalent impedance box (7) sub module , the inductance value of the power cable equivalent inductance (14) , the capacitance value of the power cable equivalent capacitor (15) , the opening time of each power cable side timing switch , the duration of each power cable side timing switch (33) opening is shown in the following formula: （1）； （2）； （3）； ，n=1，2，3，........， D / k （4）； （5）； wherein, is the dielectric constant of air; is the conductivity of the power cable; is the magnetic permeability of the power cable; d is the distance between two adjacent power cables, in meters; α is the radius of the power cable, in meters; is the height of the power cable above the ground, in meters; is the frequency of the current passing through the power cable, in Hz; is the skin depth of the cable, in meters; D is the distance between two adjacent traction substations, in meters; k is the proportional division factor; v is the uniform running speed of the train, in km / h; n is the number of equivalent impedance box modules of the power cable. The multi-module design process of the return line equivalent impedance box (13) is as follows: Take two adjacent traction substation distance as D , the line equivalent impedance box is divided into u The equivalent impedance box (13) of the return line is divided into The change of impedance on the return line is controlled by the return line side timing switch (34) between each sub-module as the train moves. When the return line side timing switch (34) reaches the set time, it is closed and opened. The order of the timer is , the direction is from the traction substation A side to the traction substation B side. The resistance value of the return line equivalent resistance (32) in each return line equivalent impedance box (13) sub-module is , the inductance value of the return line equivalent inductance (31) is , the capacitance value of the return line equivalent capacitance (30) is , the opening time of each return line side timing switch (34) is , and the duration of each return line side timing switch (34) opening is The calculation formula is as follows: （6）； （7）； （8）； ，j=1，2，3，........， D / u （9）； （10）； wherein, Each power cable equivalent impedance box (7) includes a power cable equivalent capacitor (15) connected in parallel with a power cable equivalent inductor (14) and connected in series with a power cable equivalent resistor (16), and a power cable side timing switch (33) is arranged on the connection line between each power cable equivalent impedance box (7) and the pantograph system equivalent impedance box (8). is the resistivity of the rail internal conductor, in units of ; D is the distance between two adjacent traction substations, in units of m; b is the distance between the rail equivalent cylindrical conductor axis and the rail center, in units of m; is the radius of the rail equivalent cylindrical conductor, in units of m; L is the perimeter of the rail cross section, in units of m; is the height of the rail equivalent cylindrical conductor above the ground, in units of m; is the relative permeability of the rail; is the vacuum permeability; is the vacuum permittivity; is the frequency of the current flowing through the return line, in units of Hz; is the conductivity of the rail, in units of S / m; is the skin depth of the rail, in units of m; j is the number of return line equivalent impedance box modules, u is the return line proportionality division factor; The layout design between the equivalent impedance boxes is as follows: the EMI signal emission box (1) on the A side of the traction substation / the EMI signal emission box (6) on the B side of the traction substation, the equivalent impedance box (7) of the power supply cable, the equivalent impedance box (8) of the pantograph-catenary system, the equivalent impedance box (9) of the on-board line reactor, the equivalent impedance box (10) of the on-board filter capacitor, the equivalent impedance box (11) of the on-board converter module, the equivalent impedance box (12) of the wheel set part, the equivalent impedance box (13) of the return line, and the loop antenna formed by the EMI on the A side of the traction substation to emit radiation EMI to the outside. The radiation field strength of the pantograph-catenary offline arc obtained by testing on the platform The measured radiation electric field strength of the pantograph-catenary offline arc emitted to the outside And the measured area of the loop antenna Meet the following requirements: （11）； （12）； （13）； wherein, is the area of a single loop antenna constituted by the interference loop in the actual test; is the area of a single loop antenna constituted by the interference loop in the built platform; is the wave number; is the wavelength; h is the height of the metro vehicle considering the catenary system, in m; is the distance between the metro vehicle and the traction substation, in m; is the distance between the test point and the center of the loop antenna in the actual test, in m; is the distance between the test point and the center of the loop antenna in the built platform, in m.

2. The pantograph EMI emission simulation platform for metro vehicles of urban rail transit according to claim 1, characterized in that: The vehicle-mounted filter capacitor equivalent impedance box (10) is provided with a vehicle-mounted filter capacitor parasitic inductor (22), a vehicle-mounted filter capacitor equivalent resistor (23), and a vehicle-mounted filter capacitor capacitor (24) connected in series.

3. The pantograph EMI emission simulation platform for metro vehicles of urban rail transit according to claim 1, characterized in that: Each return line equivalent impedance box (13) is provided with a return line equivalent resistor (32) connected in series with a return line equivalent capacitor (30) and a return line equivalent inductor (31) connected in parallel.

4. The pantograph EMI emission simulation platform for metro vehicles of urban rail transit according to claim 1, characterized in that: ​ 5. The pantograph EMI emission simulation platform for metro vehicles of urban rail transit according to claim 1, characterized in that: The traction substation A side EMI signal emission box (1) is internally provided with a traction substation A side radio frequency signal generator (3) and a traction substation A side power amplifier (2) connected together; the traction substation B side EMI signal emission box (6) is internally provided with a traction substation B side radio frequency signal generator (4) and a traction substation B side power amplifier (5).

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