Rail traction converter control method and rail traction converter

Abstract

The invention relates to a rail traction converter control method and a rail traction converter, and the method comprises the steps: extracting the steady-state quantity of the intermediate DC voltage of the rail traction converter; obtaining an intermediate direct-current voltage after noise filtering; based on the steady-state quantity of the intermediate direct-current voltage, the intermediate direct-current voltage after noise filtering and the electrical angular speed of the motor, the given torque compensation quantity of the motor side in the current switching period is calculated; and performing torque compensation on the motor side based on the given torque compensation amount so as to suppress the unbalanced traction current on the middle direct current side and avoid the problem of related vehicle network operation stability caused by the unbalanced traction current of the track.

Description

Technical Field

[0001] The present disclosure relates to the technical field of rail transit inverter control, and in particular to a rail traction inverter control method and a rail traction inverter. Background Art

[0002] In order to ensure the reliability of vehicle operation and driving safety, strict standards have been formulated for interference current. The interference current generated by rail vehicles mainly comes from two aspects. One is the pulse width modulation mode of the traction converter in the traditional electrical traction system, and the other is the resonance caused by the lumped energy storage elements and stray parameters in the vehicle-grid system loop. The traction converter is a more important interference source. The traction converter is a device that converts DC voltage into AC voltage. Its operating frequency is usually between 2Hz and 2kHz, and the interference current generated is mainly distributed between 2Hz and 20kHz. In addition, the amplitude of the interference current of rail vehicles is also closely related to the working conditions and control strategy of the traction system.

[0003] During the operation of rail vehicles, the energy interaction between the vehicle and the grid will introduce a large number of vehicle harmonics into the traction power supply grid. Current harmonics of certain frequencies will flow back to the grid side along the rails, causing interference to the transmission and reception of signals by the trackside equipment. The interference current generated by rail vehicles will be transmitted to other equipment or users through the power supply system, which may cause stability problems in the operation of the vehicle and the grid in severe cases. Summary of the invention

[0004] The present disclosure provides a rail traction converter control method and a rail traction converter to effectively suppress unbalanced track traction current.

[0005] In a first aspect, the present disclosure provides a rail traction converter control method, comprising:

[0006] Extract the steady-state quantity of the intermediate DC voltage of the track traction converter;

[0007] Obtain the intermediate DC voltage after noise is filtered out;

[0008] Calculating a given torque compensation amount on the motor side of the current switching cycle based on the steady-state amount of the intermediate DC voltage, the intermediate DC voltage after noise is filtered out, and the electrical angular velocity of the motor;

[0009] Torque compensation is performed on the motor side based on the given torque compensation amount to suppress unbalanced traction current on the intermediate DC side.

[0010] In some embodiments, the given torque compensation amount on the motor side of the current switching cycle is calculated based on the steady-state amount of the intermediate DC voltage, the intermediate DC voltage after noise filtering, and the electrical angular velocity of the motor, using the following calculation formula:

[0011]

[0012] In the formula, Indicates the given torque compensation on the motor side, C indicates the intermediate support capacitor, U dc_st Represents the steady-state quantity of the intermediate DC voltage, U dc1 Represents the intermediate DC voltage after noise is filtered out, ω n represents the motor electrical angular velocity, T p Represents the switching cycle.

[0013] In some embodiments, the method further comprises:

[0014] In the indirect stator quantity control process, the angle increment of the stator flux in the current switching cycle is calculated, and the angle increment includes a steady-state increment angle and a dynamic increment angle; the dynamic increment angle is calculated based on the given torque, the feedback torque, the maximum subversion torque at the previous moment, and the maximum subversion torque at the current moment;

[0015] According to the conversion relationship between the flux linkage and voltage, the stator side voltage component required for SVPWM modulation is obtained based on the angle increment, and then the magnetic field is controlled to run around the circular flux linkage trajectory.

[0016] In some embodiments, the dynamic incremental angle is calculated using the following formula:

[0017]

[0018] In the formula, Δθ dyn Indicates the dynamic increment angle in the current switching cycle, δ k represents the stator-rotor flux angle at the current moment k, δ (k-1) represents the stator-rotor flux angle at the previous moment k-1, T e * Indicates the given torque, T e Represents feedback torque, T bk represents the maximum overturning torque at the current time k, T b(k-1) Represents the maximum overturning torque at the current time k-1.

[0019] In some embodiments, the steady-state quantity of the intermediate DC voltage of the rail traction converter is extracted using the following calculation formula:

[0020]

[0021] Where U dc_st Represents the steady-state quantity of the intermediate DC voltage of the traction converter, τ L1 represents the cutoff frequency of the first-order low-pass filter, and s represents the integral.

[0022] In some embodiments, the intermediate DC voltage after noise is filtered out is obtained through an enhanced phase-locked loop.

[0023] In some embodiments, the calculation formula of the dynamic incremental angle is obtained as follows:

[0024] The first calculation formula of torque under stator flux and rotor flux is established as follows:

[0025]

[0026] Where, δ represents the stator-rotor flux angle; ψ s represents the stator flux; ψ r Represents the rotor flux; T e Indicates torque; P n Indicates the number of motor pole pairs; L σ It represents the Γ-type equivalent leakage inductance of asynchronous motor;

[0027] The rotor flux is approximately obtained according to the following second calculation formula:

[0028] |ψ r |=|ψ s |·cosδ

[0029] Convert the second calculation formula into the following third calculation formula:

[0030]

[0031] When sin2δ=1, the maximum subversion torque of the system is obtained

[0032]

[0033] According to the second and third calculation formulas, the angle between the stator and rotor flux is calculated as

[0034]

[0035] In one switching cycle, T p The dynamic incremental angle calculation formula for torque regulation is:

[0036]

[0037] In the formula, Δθ dyn Indicates the dynamic increment angle in the current switching cycle, δ k represents the stator-rotor flux angle at the current moment k, δ (k-1) represents the stator-rotor flux angle at the previous moment k-1, T e * Indicates the given torque, T e Represents feedback torque, T bkrepresents the maximum overturning torque at the current time k, T b(k-1) Represents the maximum overturning torque at the current time k-1.

[0038] In a second aspect, the present disclosure provides a rail traction converter, comprising a control unit, wherein the control unit controls the rail traction converter using the method described in the first aspect.

[0039] In a third aspect, the present disclosure provides a track induced voltage test platform for testing the transient induced voltage generated by the unbalanced traction current of the track on both sides of the rail, the track induced voltage test platform comprising:

[0040] Two first aluminum tubes simulating rail impedance, with multiple test points arranged on the first aluminum tubes for simulating the dynamic process of a train passing over a track circuit by continuously moving the test points under static conditions;

[0041] Two second aluminum tubes simulating axle impedance are respectively overlapped with the two first aluminum tubes to form a closed loop;

[0042] The resistor simulating the impedance of the axle-rail connection;

[0043] The test cables are connected to the rails on both sides respectively;

[0044] Simulate the impedance of the resonant unit in the track circuit;

[0045] The traction system is placed above the closed loop, and the placement height and the relative layout and wiring of the sub-components of the traction system simulate the layout and wiring of the real vehicle at a 1:1 ratio. The traction system includes the rail traction inverter described in claim 6.

[0046] In some embodiments, the track induced voltage testing platform is characterized in that it also includes a testing instrument, and the testing frequency of the testing instrument is set according to the working frequency band of the track circuit.

[0047] In a fourth aspect, the present disclosure provides a track induced voltage testing method, which is implemented based on the testing platform described in the third aspect, and the track induced voltage testing method includes:

[0048] Under different train operation modes, the worst working conditions of the corresponding track induced voltage are determined by testing respectively;

[0049] Determine the worst working condition of the train track induced voltage based on the worst working condition of the track induced voltage under each train operation mode;

[0050] Determine whether the track induced voltage corresponding to the worst working condition of the train track induced voltage meets the preset conditions: if the preset conditions are not met, it indicates that the track unbalanced traction current interferes with the track circuit of the train;

[0051] Among them, the train operation modes include traction acceleration mode, resistance braking mode and regenerative braking mode, and the worst working conditions of the track induced voltage include voltage, torque, speed, open circuit / short circuit.

[0052] In some embodiments, before respectively testing and determining the worst working conditions of the corresponding track induced voltages under different train operation modes, the method further includes:

[0053] After calibrating the test instrument, set it to the maximum hold mode;

[0054] The test instrument is used to perform a background noise test, including testing the environmental noise when the traction system is not powered on, and, when the traction system is powered on, separating the test cable from the aluminum tube and then short-circuiting the test cable to test the interference of the cable's own coupling;

[0055] When it is determined that the background noise meets the conditions, after the traction system is powered on, the steps of testing and determining the worst working conditions of the corresponding track induced voltage under different train operation modes are performed.

[0056] In a fifth aspect, the present disclosure provides a train and axle counter electromagnetic compatibility test and evaluation system, comprising:

[0057] The first test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under the first test bandwidth;

[0058] The second test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under a second test bandwidth; the first test bandwidth is lower than the second test bandwidth;

[0059] An acquisition system, used for continuously acquiring the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage;

[0060] Data analysis system: Based on the analog voltage data collected by the acquisition system each time, it evaluates whether the train and the trackside axle counter meet the electromagnetic compatibility. If the train to be tested and the trackside axle counter do not meet the electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method described in any one of claims 1 to 5 to control the track traction inverter.

[0061] In a sixth aspect, the present disclosure provides a train and axle counter electromagnetic compatibility test and evaluation method, which is implemented based on the train and axle counter electromagnetic compatibility test and evaluation system described in the fifth aspect, and the train and axle counter electromagnetic compatibility test and evaluation method includes:

[0062] The first test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a first test bandwidth; the second test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a second test bandwidth; the first test bandwidth is lower than the second test bandwidth;

[0063] The acquisition system continuously acquires the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage;

[0064] The data analysis system evaluates whether the train and the trackside axle counter meet electromagnetic compatibility based on the analog voltage data collected by the acquisition system each time. If the train to be tested and the trackside axle counter do not meet electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method described in the first aspect to control the track traction inverter.

[0065] The present disclosure provides a rail traction converter control method and a rail traction converter, which extracts the steady-state quantity of the intermediate DC voltage of the rail traction converter, obtains the intermediate DC voltage after noise filtering, and calculates the given torque compensation amount on the motor side of the current switching cycle in combination with the electrical angular velocity of the motor, and then performs torque compensation on the motor side based on the given torque compensation amount, so as to effectively suppress the unbalanced traction current of the track and avoid the related vehicle network operation stability problems caused by the unbalanced traction current of the track. Furthermore, the transient induced voltage generated by the unbalanced traction current on both sides of the rail is tested by the track induced voltage test platform to evaluate the suppression effect of the rail traction converter control method on the unbalanced traction current. Furthermore, the train and the trackside axle counter electromagnetic compatibility test evaluation method is used to evaluate whether the train and the trackside axle counter meet the electromagnetic compatibility, so as to evaluate whether the unbalanced traction current of the track interferes with the trackside axle counter signal system. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:

[0067] Figure 1 A schematic diagram of a typical subway train main circuit topology structure provided by an embodiment of the present disclosure;

[0068] Figure 2 A schematic diagram of the interference principle of track interference current provided in an embodiment of the present disclosure;

[0069] Figure 3 A schematic diagram of an intermediate DC voltage obtained through an EPLL according to an embodiment of the present disclosure;

[0070] Figure 4 The ISC principle block diagram provided for the embodiment of the present disclosure;

[0071] Figure 5 A stator and rotor flux vector operation diagram within a switching cycle provided by an embodiment of the present disclosure;

[0072] Figure 6 A schematic diagram of the response of a conventional PI-type ISC to a step torque provided in an embodiment of the present disclosure;

[0073] Figure 7 A schematic diagram of the response of the feedforward ISC to the phase torque provided in the embodiment of the present disclosure;

[0074] Figure 8 The 50Hz harmonic situation of the traditional ISC control strategy provided by the embodiment of the present disclosure;

[0075] Fig. 9 The feedforward ISC control strategy for 50Hz harmonic condition provided by the embodiment of the present disclosure;

[0076] Fig.10 A schematic diagram of the construction of a track induced voltage test platform provided in an embodiment of the present disclosure;

[0077] Fig.11 A top view of the traction system arrangement provided for an embodiment of the present disclosure;

[0078] Fig.12 A side view showing the arrangement of components of a traction system provided by an embodiment of the present disclosure;

[0079] Fig.13 The worst induced voltage spectrum in the typical operating mode of the traction system provided by the embodiment of the present disclosure, wherein (a) is the worst track induced voltage spectrum in the traction acceleration mode, (b) is the worst track induced voltage spectrum in the resistance braking mode, and (c) is the worst track induced voltage spectrum in the regenerative braking mode;

[0080] Fig.14 The induced voltage limit requirements for the audio band of a certain line track circuit provided in the embodiment of the present disclosure;

[0081] Fig.15 A block diagram of the train and axle counter electromagnetic compatibility test and evaluation system provided in an embodiment of the present disclosure;

[0082] Fig.16 A schematic diagram of the antenna provided in the embodiment of the present disclosure according to the position requirements;

[0083] Fig.17 A data analysis process flow chart provided for an embodiment of the present disclosure;

[0084] Fig.18 The time domain waveform of the Zp30H axle counter after the 28.8kHz over-standard frequency point is extracted;

[0085] Fig.19 A data analysis interface for electromagnetic compatibility test and evaluation of trains and axle counters provided in an embodiment of the present disclosure;

[0086] Fig. 20 A flow chart of a rail traction converter control method provided in an embodiment of the present disclosure.

[0087] In the drawings, the same reference numerals are used for the same components, and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0088] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, and to fully understand and implement how the present disclosure applies technical means to solve technical problems and achieve the corresponding technical effects, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only embodiments of a part of the present disclosure, not all of the embodiments. The embodiments of the present disclosure and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the scope of protection of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present disclosure.

[0089] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0090] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0091] The principle of track interference current generation is as follows:

[0092] At present, there are two main power supply systems for subway traction systems: one is to use the DC750V power supply system, with an allowable voltage fluctuation range of DC500~900V, and the third rail receives the current; the other is to use the DC1500V power supply system, with an allowable voltage fluctuation range of DC1000~1800V, and the overhead contact network pantograph receives the current. Generally, the rated power of the traction motor is about 200kW. Figure 1 This is a typical main circuit topology of a subway train. The traction inverter draws power from the pantograph, passes through a DC LC input filter, and drives the asynchronous motor (IM) through the IGBT. The two asynchronous motors use the frame control mode, that is, one inverter module controls two motors.

[0093] DC side current I d The return current flows back to the track through the contact network. Ideally, the return current on the two rails is equal. However, in practical applications, due to various factors (mainly the unbalanced impedance of the traction circuit itself and the magnetic field coupling of the traction current of the adjacent traction circuit), the distribution of the return current on the two rails is uneven, that is, the traction current is unbalanced, and the difference in the return current between the two rails is called unbalanced traction current. If there is an unbalanced traction current on the rail, the current may flow through the track circuit (see Figure 2 ), and the interference current has rich harmonic components in the track signal frequency band, which may affect the recognition of low-frequency modulation signals after being demodulated by the track signal receiving equipment, thereby causing malfunction of the track circuit and affecting the safety of train operation.

[0094] Embodiment 1

[0095] Fig. 20 The following is a flow chart of a method for controlling a rail traction converter provided by an embodiment of the present disclosure. Fig. 20 As shown, a rail traction converter control method can be applied to a control unit of a traction converter, the method comprising:

[0096] Step S11, extracting the steady-state quantity of the intermediate DC voltage of the track traction converter.

[0097] The energy of the intermediate DC side on the intermediate support capacitor C can be expressed as follows:

[0098]

[0099] Where W C represents the energy on the intermediate support capacitor, C represents the intermediate support capacitor, U dc Indicates the intermediate DC voltage, U dc_stRepresents the stability obtained by passing through a first-order low-pass filter.

[0100] The steady-state value of the intermediate DC voltage of the traction converter is extracted through a first-order low-pass filter LPF1 (LPF1, Low Pass Filter):

[0101]

[0102] Where U dc_st Represents the steady-state quantity of the intermediate DC voltage of the traction converter, τ L1 represents the cutoff frequency of the first-order low-pass filter LPF1, and s represents the integral.

[0103] Step S12: obtaining the intermediate DC voltage after noise is filtered out.

[0104] At present, the most common method for extracting the harmonic components of the intermediate voltage is to use a bandpass filter. However, the current assessment range of the characteristic frequency band of the track interference current in Europe is relatively wide, and the cutoff frequency of the bandpass filter cannot cover all the tested frequency bands. In some implementations of this embodiment, by Figure 3 The enhanced phase-locked loop (EPLL) shown in FIG. 1 obtains the intermediate DC voltage after filtering out the noise. This voltage contains the harmonic components of each frequency band. When the harmonic components of a certain frequency band are more prominent, U dc1 It can reflect more realistically. It uses its higher frequency range, faster lock time, and better noise performance to obtain the prominent harmonics in the intermediate voltage component. It can obtain the prominent harmonics in the intermediate voltage component in a wide-band, fast, and anti-interference manner.

[0105] Step S13, calculating a given torque compensation amount on the motor side of the current switching cycle based on the steady-state amount of the intermediate DC voltage, the intermediate DC voltage after noise is filtered out, and the electrical angular velocity of the motor.

[0106] Traditionally, only the primary deviation value of the intermediate voltage is used to adjust the torque for suppression compensation of interference current. This embodiment adopts the compensation method of the square difference of the intermediate voltage based on the energy flow relationship between the DC side and the AC side to accurately compensate for the torque regulation. It can more accurately feedback the torque according to the fluctuation of the intermediate voltage.

[0107] The energy fluctuation on the intermediate support capacitor can be obtained according to formula (1):

[0108]

[0109] When ΔW CWhen it is greater than 0, it means that the energy on the intermediate side increases, and vice versa, it means that the energy on the intermediate side decreases. When the energy on the intermediate side fluctuates, in order to maintain stable energy, it is necessary to adjust it on the motor side. The energy expression on the motor side is as follows

[0110]

[0111] Where P m Represents the motor side power, ω n represents the motor electrical angular velocity, Indicates the motor given torque, that is, the motor command torque.

[0112] In a switching cycle T p , the energy on the motor side can be expressed as

[0113]

[0114] On the DC side and the AC side, according to the energy transfer process, there is the following equivalent relationship

[0115]

[0116] Furthermore, the intermediate DC side can be stably controlled by compensating the torque at the motor end.

[0117] According to formula (6), we can get

[0118]

[0119] In the formula, Indicates the given torque compensation on the motor side, C indicates the intermediate support capacitor, U dc_st Represents the steady-state quantity of the intermediate DC voltage, U dc1 Represents the intermediate DC voltage after noise is filtered out, ω n represents the motor electrical angular velocity, T p Represents the switching cycle.

[0120] When the intermediate voltage on the DC side fluctuates upward, the energy consumption is increased by increasing the given torque on the motor side; when the intermediate voltage on the DC side fluctuates downward, the energy consumption is reduced by reducing the given torque on the motor side, thereby suppressing the fluctuation of the intermediate voltage on the DC side. Based on the steady-state quantity of the intermediate DC voltage, the intermediate DC voltage after noise filtering, and the motor electrical angular velocity, the given torque compensation on the motor side of the current switching cycle is calculated using formula (7), which is more accurate than the original method of only using the difference in the intermediate voltage to adjust the torque.

[0121] Step S14: Perform torque compensation on the motor side based on a given torque compensation amount to suppress unbalanced traction current on the intermediate DC side.

[0122] By extracting the steady-state quantity of the intermediate DC voltage of the track traction inverter and obtaining the intermediate DC voltage after filtering out the noise, combined with the electrical angular velocity of the motor, the given torque compensation amount on the motor side of the current switching cycle is calculated, and then the torque compensation on the motor side is performed based on the given torque compensation amount. This achieves accurate feedback compensation of the fluctuation of the intermediate DC voltage to the torque, so as to effectively suppress the interference current of the track unbalanced traction current and avoid the related vehicle-grid operation stability problems caused by the track unbalanced traction current.

[0123] The traditional PI type indirect stator quantity control principle is as follows Figure 4 As shown. By sampling the motor current i a and i b , considering the inverter model error and combining the high-precision voltage reconstruction technology, the reconstructed voltage u is obtained a 、u b and u c ; Obtain i through 3 / 2 transformation sα 、i sβ 、u sα 、u sβ ; Then, we can get |ψ by using the full-order flux observer motor model s |、|ψ r |、T e , steady-state increment angle Δθ stat It is obtained by the following formula

[0124]

[0125] In the formula, ψ s represents the stator flux; ψ r Represents the rotor flux; T * e Indicates the given torque; R r Represents the rotor resistance in the Γ-type equivalent circuit of the asynchronous motor; ω n Indicates the motor feedback speed; ω 1 represents the stator angular frequency, ω s Slip angular velocity; T p Indicates the switching cycle; P n Indicates the number of motor pole pairs.

[0126] Given torque T * e With feedback torque T e Through the PI regulator, the dynamic incremental angle Δθ is output dyn

[0127]

[0128] Δθ is the angular increment of the stator flux in one switching cycle

[0129] Δθ=Δθstat +Δθ dyn (10)

[0130] According to the conversion relationship of flux linkage voltage, see formula (11), the required U modulated by SVPMW is obtained: sα Quantity and U sβ component, thereby controlling the magnetic field to run around the circular flux trajectory.

[0131]

[0132] In the formula, R s represents the rotor resistance in the Γ-type equivalent circuit of the asynchronous motor, i s Indicates the stator current, U s Indicates the stator side voltage, Indicates the change in magnetic flux.

[0133] From the above-mentioned traditional ISC (Indirect Stator-flux-oriented Control) control, it can be seen that the torque regulation adopts PI control, as shown in formula (9), with an integral inertia link, which will affect the response speed of the torque regulation. The ISC control in this embodiment removes the integral link in the traditional PI control, and derives the theoretical formula of the stator flux dynamic phase angle increment (dynamic increment angle) based on the relationship between the stator and rotor flux angle and the torque in a switching cycle, thereby eliminating the integral link and greatly improving the torque response speed.

[0134] In some embodiments, the method of this embodiment further includes:

[0135] In the indirect stator quantity control process, the angle increment of the stator flux in the current switching cycle is calculated, and the angle increment includes a steady-state increment angle and a dynamic increment angle; the dynamic increment angle is calculated based on the given torque, the feedback torque, the maximum subversive torque at the previous moment, and the maximum subversive torque at the current moment; and

[0136] According to the conversion relationship between flux linkage and voltage, the stator side voltage component required for SVPWM modulation is obtained based on the angle increment, and then the magnetic field is controlled to run around the circular flux linkage trajectory.

[0137] Figure 5 The stator and rotor flux vector operation diagram within a switching cycle. The subscript k represents the current moment, and the subscript k-1 represents the previous moment. The current moment and the previous moment differ by a switching cycle T. p The first calculation formula for torque under stator flux and rotor flux is established, which can be expressed as follows:

[0138]

[0139] Where, δ represents the stator-rotor flux angle; ψ s represents the stator flux; ψ r Represents the rotor flux; T e Indicates torque; P n Indicates the number of motor pole pairs; L σ Represents the Γ-type equivalent leakage inductance of the asynchronous motor.

[0140] Since the stator and rotor flux angle is small, the rotor flux can be approximated by the following second calculation formula

[0141] |ψ r |=|ψ s |·cosδ (13)

[0142] The second calculation formula of formula (13) is transformed into the following third calculation formula

[0143]

[0144] When sin2δ=1, the maximum subversion torque of the system can be obtained

[0145]

[0146] According to equations (13) and (14), the angle between the stator and rotor flux can be calculated as:

[0147]

[0148] In one switching cycle, T p The dynamic incremental angle of torque regulation can be rewritten as follows:

[0149]

[0150] In the formula, Δθ dyn Indicates the dynamic increment angle in the current switching cycle, δ k represents the stator-rotor flux angle at the current moment k, δ (k-1) represents the stator-rotor flux angle at the previous moment k-1, T e * Indicates the given torque, T e Represents feedback torque, T bk represents the maximum overturning torque at the current time k, T b(k-1) The dynamic incremental angle is calculated by equation (17) to realize feedforward ISC control, which does not require the traditional ISC to use an integral link to ensure the feedback torque and the given torque are tracked without deviation.

[0151] The torque regulation in the traditional ISC control adopts PI control with an integral inertia link, which will affect the response speed of the torque regulation. When there is harmonic disturbance in the intermediate DC side current, the torque response speed of the traditional method cannot be effectively adjusted. However, this embodiment adopts feedforward indirect stator quantity control, cancels the integral delay link in the traditional control link, brings a faster torque response speed, can effectively suppress the interference current generated by the rail vehicle, and the step torque response time can reach about 2ms, with basically no overshoot, which has a good inhibitory effect on the stability of the DC current on the intermediate DC side and effectively suppresses the interference current.

[0152] Figure 6 and Figure 7 This is a comparison of the two methods for step torque response. It can be seen from the figure that the torque response of the traditional PI-type ISC has lag and overshoot, while the torque response of the feedforward ISC in this embodiment is fast and the tracking is stable, which effectively verifies the fast torque response characteristics of this embodiment.

[0153] During the test, the test system is simulated to accelerate to stability and then decelerate. That is, the test system drags the test system to run stably to 200r / min, the test system is loaded to the rated value, and then dragged to 800r / min by the test motor, and then decelerated to 200r / min. The intermediate DC current is collected, and then the 50Hz frequency band harmonics of the intermediate DC current are compared and analyzed. The analysis is based on the 0.72A limit standard of a subway at 50Hz, such as Figure 8 and Fig. 9 As shown, the analysis shows that the traditional control strategy has a large amplitude at 800r / min and exceeds the limit standard; while the feedforward ISC control strategy has a good inhibitory effect on the DC current stability of the intermediate DC side, and the intermediate DC current harmonic amplitude at 50Hz is basically below the limit.

[0154] Embodiment 2

[0155] An embodiment of the present disclosure provides a rail traction inverter, including a control unit, and the control unit uses the method provided in the first embodiment to control the rail traction inverter.

[0156] It should be understood that this embodiment has all the beneficial effects of the first embodiment.

[0157] Embodiment 3

[0158] The track unbalanced traction current (interference current) mentioned in the above content cannot be directly tested. Before or after being suppressed by the method of Example 1, it is impossible to evaluate whether the track unbalanced traction current interferes with the track circuit of the train through the measured value of the track unbalanced traction current, or verify the suppression effect of the track unbalanced current after the implementation of the method of Example 1. Instead, it is analyzed by the amplitude of the intermediate DC current in the characteristic frequency band. In addition, the above test is a ground combination test, which may be different from the situation of the whole vehicle on the track surface. In order to better evaluate the size of the track interference current, the embodiment of the present disclosure provides a track induced voltage test platform for testing the transient induced voltage generated by the track unbalanced traction current on both sides of the rail. The track induced voltage test platform includes:

[0159] Two first aluminum tubes simulating rail impedance, with multiple test points arranged on the first aluminum tubes for simulating the dynamic process of a train passing over a track circuit by continuously moving the test points under static conditions;

[0160] Two second aluminum tubes simulating axle impedance are respectively overlapped with the two first aluminum tubes to form a closed loop;

[0161] The resistor simulating the impedance of the axle-rail connection;

[0162] The test cables are connected to the rails on both sides respectively;

[0163] Simulate the impedance of the resonant unit in the track circuit;

[0164] The traction system is placed above the closed loop, and the placement height and the relative layout and wiring of the sub-components of the traction system simulate the layout and wiring of the real vehicle at a 1:1 ratio. The traction system includes the rail traction inverter described in claim 6.

[0165] In this embodiment, a train traction system-rail-track circuit joint test platform is built according to a 1:1 ratio simulation of the actual layout and wiring of the whole vehicle. Through ground static testing, it truly restores the process in which the track interference current generates transient induced voltage on both sides of the rail during the dynamic operation of the train, thereby interfering with the track circuit, providing a solution for the actual dynamic track induced voltage testing and suppression of the whole vehicle.

[0166] Fig.10 This is a specific example of a track induced voltage test platform, where: 01: an aluminum tube simulating rail impedance; 02: an aluminum tube simulating axle impedance; 03: an aluminum tube simulating rail impedance; 04: a resistor simulating the impedance of the axle-rail connection; 05: an aluminum tube simulating axle impedance; 06: a twisted-pair test cable, which is well overlapped with the rails on both sides; 07: an audio FFT analyzer; 08: a test point; 09: the impedance of the resonant unit in the simulated track circuit; 10: a traction system.

[0167] The track induced voltage test platform uses two long aluminum tubes and two short aluminum tubes to form a closed loop. The long aluminum tube is used to simulate the actual rail, and the two short aluminum tubes are used to simulate the vehicle axle. There are certain requirements for the aluminum tube model, outer diameter, and wall thickness.

[0168] The traction system is placed above the closed loop of aluminum tubes. The placement height and relative layout and wiring of the traction system sub-components are completely 1:1 to simulate the layout and wiring of the real vehicle. Fig.10 A top view showing the layout of the traction system subcomponents is shown. Fig.11 A side view showing the arrangement of the various subcomponents of the traction system. (The motor is actually present but is not shown in the figure). Fig.12 A side view showing the arrangement of the components of the traction system.

[0169] R A Used to simulate the overlap impedance between the vehicle axle and the rail, with a value of 0.1~0.2Ω (R A , directly short circuit). The entire test is divided into short circuit test (R A Connection) and open circuit test (R A The short circuit test is used to simulate a train passing over the track circuit, and the track circuit is in a closed loop formed by the rails and axles. The open circuit test is used to simulate a train axle crossing the rail insulation joint, and the track circuit is in a loop formed by the rails and axles.

[0170] R B It is used to simulate the impedance of the track circuit tuning unit, and the value is 0~2Ω. The track induced voltage is the voltage measured at both ends. R can be omitted here. B , directly measure the open circuit voltage, or connect a real track circuit tuning unit.

[0171] 0,1,2...n means that the test points need to be moved continuously, and the test values ​​are taken from the maximum values ​​measured at these points, which is used to simulate the dynamic process of a train passing over the track circuit under static conditions. The distance between adjacent test points is 0.1 to 0.5m.

[0172] The test cables are twisted in pairs to minimize the spatial magnetic field coupled to the cable loop. Each cable should be fastened and overlapped with the aluminum tube using a rail clamp.

[0173] In some cases, the track induced voltage test platform also includes a test instrument, and the test frequency of the test instrument is set according to the track circuit operating frequency band. In one example, the test instrument uses an audio FFT analyzer, and the test frequency should be set according to the track circuit operating frequency band, such as between tens of Hz and tens of kHz, and the instrument test accuracy should reach the uV level.

[0174] Embodiment 4

[0175] The present disclosure provides a method for testing track induced voltage, which is implemented based on the test platform of the third embodiment. The method for testing track induced voltage includes:

[0176] Under different train operation modes, the worst working conditions of the corresponding track induced voltage are determined by testing respectively;

[0177] Determine the worst working condition of the train track induced voltage based on the worst working condition of the track induced voltage under each train operation mode;

[0178] Determine whether the track induced voltage corresponding to the worst working condition of the train track induced voltage meets the preset conditions: if the preset conditions are not met, it indicates that the track unbalanced traction current interferes with the track circuit of the train; if the preset conditions are met, it indicates that the track unbalanced traction current does not interfere with the track circuit of the train.

[0179] Among them, the train operation modes include traction acceleration mode, resistance braking mode and regenerative braking mode, and the worst operating conditions of track induced voltage include voltage, torque, speed, open circuit / short circuit.

[0180] In some cases, before respectively testing and determining the worst working conditions of the corresponding track induced voltages in different train operation modes, the testing method of this embodiment further includes:

[0181] After calibrating the test instrument, set it to the maximum hold mode;

[0182] Use the test instrument to test the background noise, including testing the environmental noise when the traction system is not powered on, and, when the traction system is powered on, separate the test cable from the aluminum tube and then short-circuit the test cable to test the interference of the cable coupling itself;

[0183] When it is determined that the background noise meets the conditions, after the traction system is powered on, the steps of testing and determining the worst working conditions of the corresponding track induced voltage under different train operation modes are performed.

[0184] In a specific example, the process of the track induced voltage test method is as follows:

[0185] Step 1: According to Fig.10 Build a track induced voltage test platform, and the components of the traction system are tested according to Fig.11 and Fig.12 Make arrangements.

[0186] Step 2: After calibrating the audio FFT analyzer, set it to the maximum hold mode, with the analysis band set based on the track circuit operating frequency band and a frequency resolution of several Hz.

[0187] Step 3: Perform background noise test:

[0188] ① Test the environmental noise when the traction system is not powered on. 2 to 3 test points can be selected;

[0189] ② When the traction system is powered on, separate the test cable from the aluminum tube, and then short-circuit the test cable to test the interference of the cable's own coupling. 2 to 3 test points can be selected.

[0190] Step 4: After confirming that the background noise is small enough and meets the conditions, conduct a formal test after the traction system is powered on:

[0191] Traction acceleration mode - open circuit (R A Open) and short circuit (R A Connection) test, the test points include all test points. Determine the worst working condition of the track induced voltage in this mode (including specific test points, open circuit or short circuit);

[0192] Resistor braking mode - open circuit (R A Open) and short circuit (R A Connection) test, the test points include all test points. Determine the worst working condition of the track induced voltage in this mode (including specific test points, open circuit or short circuit);

[0193] Regenerative braking mode - open circuit (R A Open) and short circuit (R A Connection) test, the test points include all test points. Determine the worst working condition of the track induced voltage in this mode (including specific test points, open circuit or short circuit);

[0194] In some cases, after determining the worst working conditions of the track induced voltage in the above three modes (including specific test points, open circuit or short circuit), the rated voltage is reduced to 80% and 60%, and the test is performed again under the worst working conditions.

[0195] In a specific example, the worst induced voltage spectrum in a typical operating mode of a traction system is as follows: Fig.13 As shown, Fig.13 Among them, (a) is the worst track induced voltage spectrum in traction acceleration mode, (b) is the worst track induced voltage spectrum in resistance braking mode, and (c) is the worst track induced voltage spectrum in regenerative braking mode.

[0196] Step 5. After all the worst working conditions mentioned above are completed, find the mode, induced voltage, torque, speed, open circuit / short circuit corresponding to the worst working conditions of track induced voltage. If the track induced voltage corresponding to the worst working condition does not meet the relevant requirements, measures to suppress the induced voltage should be formed under this condition to provide a solution for the subsequent dynamic track induced voltage test of the whole vehicle.

[0197] In one example, the induced voltage limit requirement for the audio frequency band of a certain line track circuit is as follows: Fig.14 shown.

[0198] It should be noted that the track induced voltage test method of this embodiment can be implemented before or after the method of embodiment 1 is executed. In the case of implementation before execution, it is determined whether to execute the method of embodiment 1 by judging whether the track induced voltage corresponding to the worst working condition of the train track induced voltage meets the preset conditions, and then judging whether the track unbalanced traction current interferes with the track circuit of the train. In the case of implementation after execution, it is determined whether the effect of executing the method of embodiment 1 on suppressing the track unbalanced traction current (track interference current) by judging whether the track induced voltage corresponding to the worst working condition of the train track induced voltage meets the preset conditions, and then judging whether the track unbalanced traction current interferes with the track circuit of the train.

[0199] Embodiment 5

[0200] The axle counter is a safety device used to detect whether the axle of a train occupies a track section. Compared with the track circuit, it has a series of advantages such as being unaffected by the track route conditions, no need to cut the track, and no need to install track insulation, and is suitable for long and large track sections. Therefore, it is favored by the railway transportation department. However, with the popularization and promotion of axle counters in the track ground signal system and the development trend of high voltage, high power and high switching frequency of electrified vehicles, the electromagnetic compatibility problem between the two is becoming increasingly severe. The magnitude of the track interference current will also affect the signal system of the axle counter. Standards such as EN 50238-3 and EN 50617 specify relevant test methods and specific limit requirements for the vehicle's interference with the magnetic field of the axle counter. The GB / T 28807.3 standard is used to control the electromagnetic compatibility between vehicles and axle counters. At present, domestic trains (subways, EMUs, diesel locomotives, etc.) must be evaluated and certified for electromagnetic compatibility with axle counters before they are exported to overseas regions and put into operation on lines equipped with axle counters in domestic coastal areas.

[0201] However, due to the large number of axle counter types in the railway industry, different working signal formats, and overlapping working frequency bands, the electromagnetic compatibility assessment methods for different types of axle counters and vehicles are also different. At present, the domestic rail transit field lacks a complete electromagnetic compatibility assessment and test system that can cover the entire frequency band and all axle counter types. In this context, the system provided in this embodiment fills this technical gap.

[0202] The embodiment of the present disclosure provides a train and axle counter electromagnetic compatibility test and evaluation system for testing and evaluating the electromagnetic compatibility of a train and a trackside train and an axle counter, the system comprising:

[0203] The first test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under the first test bandwidth;

[0204] The second test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under a second test bandwidth; the first test bandwidth is lower than the second test bandwidth;

[0205] An acquisition system, used for continuously acquiring the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage;

[0206] Data analysis system: Based on the analog voltage data collected by the acquisition system each time, it is evaluated whether the train and the trackside axle counter meet the electromagnetic compatibility. If the train to be tested and the trackside axle counter do not meet the electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method of embodiment 1 to control the track traction inverter.

[0207] The first test antenna is a low-frequency test antenna, the second test antenna is a high-frequency test antenna, and the magnetic field signal may refer to an electromagnetic wave signal.

[0208] The system of this embodiment determines whether the train and the trackside axle counter meet electromagnetic compatibility by using electromagnetic wave signals received by high and low frequency test antennas, so as to evaluate whether the unbalanced track current interferes with the trackside axle counter signal system, so as to evaluate the effectiveness of the method of embodiment one, or before executing the method of embodiment one, first determine whether the unbalanced track current interferes with the trackside axle counter signal system, and if the unbalanced track current interferes with the trackside axle counter signal system, then execute the method of embodiment one to suppress the interference of the unbalanced track current.

[0209] In a specific example, a train and axle counter electromagnetic compatibility test and evaluation system is as follows: Fig.15 As shown:

[0210] 01 - Train to be tested: In normal mode and degraded mode, the train passes through the antenna with 1 / 3 of the maximum traction force, accelerating from speed v1 to speed v3 or braking from speed v3 to speed v1.

[0211] 02——Low-frequency test antenna: Contains three independent orthogonal coils, which receive magnetic field signals (electromagnetic wave signals) emitted by trains in the X, Y and Z directions. The test bandwidth is 10kHz~100kHz.

[0212] 03——High frequency test antenna: It contains three independent orthogonal coils, which receive magnetic field signals (electromagnetic wave signals) emitted by trains in the three directions of X, Y and Z. The test bandwidth is 100kHz~1.3MHz; the antenna installation position complies with the PD CLC-TS50238-3 standard, such as Fig.16 shown.

[0213] 04, 05——High-speed acquisition system: The X, Y, and Z magnetic field interference received by the high-frequency and low-frequency test antennas is collected continuously at high speed in at least 6 channels in the form of analog voltage. The single-channel sampling frequency meets 3MHz / s, and the continuous acquisition time meets the required time for the train to pass through the test antenna completely. The entire acquisition system uses NI acquisition boards as hardware, and the acquisition interface of the upper computer human-computer interaction is written through Labview. The test engineer can set the sampling rate, signal range, source impedance, etc. in the interface.

[0214] 06——Data analysis system: Analyze and process up to 6 channels of voltage data collected by the high-speed acquisition system each time, so as to evaluate whether the train and the axle counter meet the electromagnetic compatibility.

[0215] The data analysis system is developed based on the Matlab GUI platform. The entire data analysis process is as follows: Fig.17 As shown:

[0216] ① Data input module: responsible for storing at least 6 channels of large-capacity signal data continuously collected by the high-speed acquisition system (acquisition board) into the Matlab memory, and compressing the signal data into binary format in this module. This function can reduce the subsequent signal processing time by at least 90% and realize instant online result determination of field tests.

[0217] ②Analysis mode selection module: defines two analysis modes, including: analysis mode based on TSI CCS and analysis mode based on specific axle counters. The former needs to analyze the working frequency band of 10kHz-1.3MHz including all axle counter types, while the latter only needs to analyze the working frequency band of specific types of axle counters (such as 27kHz-32kHz of ZP30H). The two modes have different analysis algorithms and evaluation criteria.

[0218] When the TSI CCS analysis mode is selected, the system automatically assigns the respective short-time Fourier analysis parameters, including the Hanning window length and overlap ratio, for the initial calculation of the three out-band and three in-band frequency bands.

[0219] In one example, when the TSI CCS analysis mode is selected, the system automatically divides the analysis frequency band into six intervals, including three axle counter working bands (In-band) and three working bands (Out-band), and assigns different short-time Fourier analysis parameters to each interval for the first time, as shown below:

[0220] Out-band1

[0221] Analysis frequency band: 10kHz-27kHz;

[0222] Short-time Fourier parameters: Hanning window, window time 1ms, overlap rate 50%.

[0223] In-band1

[0224] Analysis frequency band: 27kHz-52kHz;

[0225] Short-time Fourier parameters: Hanning window, window time 1ms, overlap rate 75%.

[0226] Out-band2

[0227] Analysis frequency band: 52kHz-234kHz;

[0228] Short-time Fourier parameters: Hanning window, window time 1ms, overlap rate 50%.

[0229] In-band2

[0230] Analysis frequency band: 234kHz-363kHz;

[0231] Short-time Fourier parameters: Hanning window, window time 0.5ms, overlap rate 75%.

[0232] Out-band3

[0233] Analysis frequency band: 363kHz-740kHz;

[0234] Short-time Fourier parameters: Hanning window, window time 1ms, overlap rate 50%.

[0235] In-band3

[0236] Analysis frequency band: 740kHz-1250kHz;

[0237] Short-time Fourier parameters: Hanning window, window time 0.5ms, overlap rate 75%.

[0238] When a specific axle counter analysis mode is selected, the system will assign digital filtering and integration parameters to each axle counter type, including filter type, filter order, filter bandwidth, center frequency point moving step, integration time and integration window overlap rate.

[0239] In one example, when a specific axle counter analysis mode is selected, the system automatically divides the axle counter into 17 types for selection, and each type of axle counter has different preset digital filter analysis parameters. Taking Thales' Zp30H axle counter as an example, its digital filter analysis parameters are as follows:

[0240] Zp30H axle counter

[0241] Analysis frequency band: 27kHz-32kHz; filter type: Butterworth fourth-order bandpass filter; 3dB bandwidth: 240Hz; filter center frequency moving step: 80% of 3dB bandwidth; integration time: 4ms; overlap rate 75%.

[0242] ③Analysis direction selection module: The user defines the data direction for each analysis. Combined with the analysis frequency band in ②, the system automatically allocates the antenna compensation coefficient and standard limit for this direction and frequency band.

[0243] In one example, the user defines the analysis direction of the data, combined with the analysis frequency band, and the system automatically assigns antenna calibration compensation factors and standard limits for evaluation based on the technical manual provided by the antenna manufacturer and the European axle counter standard document, for example:

[0244] a. Analysis mode: TSI CCS mode; Analysis frequency band: In-band1 (27kHz-52kHz); Analysis direction: X direction.

[0245] Standard limit: 93dBuA / m; Antenna coefficient: 36dB@27kHz, 31dB@52kHz (the antenna coefficient of the intermediate frequency point is obtained by interpolation algorithm).

[0246] b. Analysis mode: specific axle counter mode; axle counter type: Zp30H; analysis frequency band: 27kHz-32kHz; analysis direction: Z direction.

[0247] Standard limit: 101dBuA / m; antenna factor: 36dB@27kHz, 35.5dB@32kHz (the antenna factor of the intermediate frequency point is obtained by interpolation algorithm).

[0248] ④TSI CCS initial calculation module: It uses the short-time Fourier algorithm to calculate, and the calculated voltage result is compensated for the antenna coefficient and compared with the standard magnetic field limit. This module has a fast calculation speed and can be used for the initial scanning judgment of the result.

[0249] The mathematical formula for short-time Fourier transform is:

[0250]

[0251] s(t) is the input voltage time domain data;

[0252] h(t) is the window function.

[0253] The mathematical formula for converting the voltage superposition antenna compensation coefficient into a magnetic field value is:

[0254] s(f) dBuA / m =s(f) dBvV +AF(f) dB

[0255] s(f) dBuA / m is the converted frequency domain magnetic field value;

[0256] s(f) dBuV is the frequency domain voltage value obtained by short-time Fourier calculation;

[0257] AF(f) dB is the antenna compensation coefficient.

[0258] ⑤ Calculation module for specific axle counter: Perform digital filtering analysis on the frequency band corresponding to the selected axle counter, superimpose the calculated voltage result with the antenna compensation coefficient and compare it with the standard magnetic field limit.

[0259] In one example, digital bandpass filtering + sliding integration processing is performed on the data in the frequency band corresponding to the selected axle counter type, and the calculated voltage result is superimposed with the antenna compensation coefficient and compared with the standard magnetic field value (standard limit value) for judgment.

[0260] The calculation process is as follows:

[0261] Step 1: Calculate the coefficients of the first Butterworth bandpass filter, where the center frequency of the filter is the starting frequency f of the analysis band start .

[0262] [b,a]=butter(n,[W1,W2],'bandpass')

[0263] n is the order of the bandpass filter designed by butter();

[0264] butter(n,[W1,W2]) will return the 2*n order filter coefficients;

[0265] W1, W2 are the 3dB cutoff frequencies of the bandpass filter;

[0266] b is the numerator polynomial coefficient of the system transfer function;

[0267] a is the denominator polynomial coefficient of the system transfer function.

[0268] Step 2: Bandpass filtering of data.

[0269] s(t) withfilter =filter(b,a,s(t) withoutfilter )

[0270] s(t) withfilter is the data after filtering;

[0271] s(t) withoutfilter is the data before filtering.

[0272] Step 3: Data is processed by sliding integration.

[0273] s(t) withfilter+rms =rms[s(t) withfilter ,T int ,overlap]

[0274] s(t) withfilter For data that is only filtered;

[0275] T int is the integration time;

[0276] overlap is the integral overlap rate;

[0277] s(t) withfilter+rms The data are processed by sliding integration.

[0278] Step 4: Take s(t) withfilter+rms The maximum value in the data is taken as the center frequency f of the first Butterworth bandpass filter. start The corresponding calculation result is expressed as s(f 1 ).

[0279] Step 5: Calculate the coefficients of the second Butterworth bandpass filter, with the center frequency of the filter being f start +Δf, Δf is the moving step of the filter center frequency.

[0280] Step 6: Bandpass filtering of data.

[0281] Step 7: The data is processed by sliding integration.

[0282] Step 8: Take the maximum value of the data after bandpass filtering + sliding integration as the center frequency f of the second Butterworth bandpass filter start +Δf corresponding to the calculation result, expressed as s(f 2 ). ......

[0284] When designing the center frequency f of the Nth Butterworth bandpass filter start +N*Δf is greater than the end frequency f of the analysis frequency band stop , ending the bandpass filtering + sliding integration process.

[0285] The last step: convert the voltage superimposed antenna compensation coefficient into a magnetic field value.

[0286] s(f) dBuA / m =s(f) dBvV +AF(f) dB

[0287] s(f) dBuA / m is the converted frequency domain magnetic field value;

[0288] s(f) dBuV is the frequency domain voltage value obtained by short-time Fourier calculation;

[0289] AF(f) dB is the antenna compensation coefficient.

[0290] ⑥TSI CCS initial calculation judgment: If the calculation results of the 3 Out-band and 3 In-band frequency bands do not exceed the limit values ​​in the three directions of X, Y, and Z, the train and the axle counter are judged to meet the electromagnetic compatibility in this test. If the calculation results of some frequency bands exceed the limit values, the judgment is entered into ⑧.

[0291] ⑦ Calculation judgment of specific axle counter analysis: If the calculation results of the corresponding frequency band of the selected axle counter do not exceed the limit values ​​in the three directions of X, Y, and Z, then the train and the axle counter are judged to meet the electromagnetic compatibility in this test. If the calculation results exceed the limit values, then the train and the axle counter are judged to not meet the electromagnetic compatibility in this test, and the user can choose to perform vehicle interference positioning analysis.

[0292] ⑧TSI CCS In-band frequency band exceeding standard judgment: If the calculation result of ⑥ output exceeds the standard within the In-band frequency band, enter ⑨ for secondary calculation; if the calculation result of ⑥ output does not exceed the standard within the In-band frequency band but exceeds the standard in the Out-band frequency band, it is judged in this test that the train and the axle counter do not meet the electromagnetic compatibility, and the user can choose to perform vehicle interference location analysis.

[0293] ⑨TSI CCS secondary calculation module: Perform secondary calculation on the In-band frequency band exceeding the standard determined by ⑧, and use a series of digital filters for analysis, such as Figure 6 As shown. Taking the In-band1 (27kHz-52kHz) analysis as an example, the center frequency of the first 4th-order Butterworth bandpass filter is 27kHz and the bandwidth is 300Hz. After the time domain data passes through the filter, an integral calculation with at least 75% overlap is performed and the maximum value is taken. This value represents the voltage at the frequency of 27kHz. The center frequency of the second filter is 27.24kHz. The same processing is performed to take the maximum value to represent the voltage at the frequency of 27.24kHz. The data processing in the frequency band of 27kHz-52kHz is completed in this way. Finally, the antenna coefficient is compensated to convert the voltage value into a magnetic field value and compare it with the limit value. Generally speaking, the result of the digital filtering analysis in the secondary calculation is smaller than the result of the short-time Fourier analysis in the initial calculation, but the calculation time is longer.

[0294] Secondary calculation module of TSI CCS: Secondary calculation is performed on the In-band frequency band that exceeds the standard determined in Part ⑧, and the data is processed using digital bandpass filtering + sliding integration. The calculated voltage result is compensated for the antenna coefficient and compared with the standard magnetic field value for judgment. The processing flow is similar to that in the specific axle counter calculation module in Part ⑤, except that the analysis frequency band and analysis parameter settings are different.

[0295] Taking the data processing of In-band3 as an example, the analysis frequency band and analysis parameters are as follows:

[0296] Analysis frequency band: 740kHz-1250kHz; filter type: Butterworth fourth-order bandpass filter; 3dB bandwidth: 1000Hz; filter center frequency moving step: 80% of 3dB bandwidth; integration time: 1.5ms; overlap rate 75%.

[0297] ⑩ TSI CCS judgment after secondary calculation: If the result of secondary calculation of all In-band frequency band data exceeding the standard is less than the standard limit, the train and the axle counter are judged to meet the electromagnetic compatibility in this test. If the result is greater than the standard limit, the train and the axle counter are judged to be not in line with the electromagnetic compatibility. Users can choose to perform vehicle interference location analysis.

[0298] Take Zp30H axle counter as an example. Fig.18The time domain waveform after the 28.8kHz over-standard frequency point of this type of axle counter is extracted is given. It can be found that in the process from the front of the vehicle passing the test antenna to the rear of the vehicle leaving the test antenna, the magnetic field emitted by the vehicle itself exceeds the standard limit shown by the red line around the 5th and 10th seconds. Combined with the vehicle running speed in this round of tests, the vehicle running position corresponding to the over-standard time point can be calculated, thereby locating the vehicle interference source and providing a solution for subsequent vehicle rectification. The data analysis interface for the electromagnetic compatibility test evaluation of trains and axle counters provided in this embodiment is as follows Fig.19 As shown in the figure, the initial calculation results of the TSI CCS analysis mode in a certain test are given.

[0299] Embodiment 6

[0300] The embodiment of the present disclosure provides a method for testing and evaluating electromagnetic compatibility between a train and an axle counter, which is implemented based on the electromagnetic compatibility testing and evaluation system for a train and an axle counter of the fifth embodiment. The method for testing and evaluating electromagnetic compatibility between a train and an axle counter includes:

[0301] The first test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a first test bandwidth; the second test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a second test bandwidth; the first test bandwidth is lower than the second test bandwidth;

[0302] The acquisition system continuously acquires the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage;

[0303] The data analysis system evaluates whether the train and the trackside axle counter meet electromagnetic compatibility based on the analog voltage data collected by the acquisition system each time. If the train to be tested and the trackside axle counter do not meet electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method described in the first aspect to control the track traction inverter.

[0304] The specific implementation details of this method can be found in Example 5.

[0305] It should be noted that the train and axle counter electromagnetic compatibility test and evaluation method of this embodiment can be implemented before or after the method of embodiment one is executed. In the case of implementation before execution, the train and the trackside axle counter are evaluated for electromagnetic compatibility by collecting the analog voltage data collected by the acquisition system each time, and then the track unbalanced traction current interferes with the trackside axle counter signal system to determine whether to execute the method of embodiment one. In the case of implementation after execution, the train and the trackside axle counter are evaluated for electromagnetic compatibility by collecting the analog voltage data collected by the acquisition system each time, and then the track unbalanced traction current interferes with the trackside axle counter signal system to determine the effect of executing the method of embodiment one on suppressing the track unbalanced traction current (track interference current).

[0306] Embodiment 7

[0307] Based on the above embodiment, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above embodiment 1.

[0308] In some implementations of this embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the above embodiment 1 are implemented.

[0309] In some implementations of this embodiment, a computer program product is provided, including a computer program, which implements the steps of the method described in the above embodiment 1 when executed by a processor.

[0310] The processor may include, but is not limited to, one or more processors or microprocessors, etc. Each processor may be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components to execute the methods in the above embodiments.

[0311] The computer-readable storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, and the computer-readable storage medium may include but is not limited to, for example, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).

[0312] The computer-readable storage medium may also store at least one computer executable program / instruction, which may be, for example, a computer-readable instruction. The computer-readable storage medium includes, but is not limited to, for example, a volatile memory and / or a non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The computer-readable storage medium may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device runs the computer-readable instructions stored on the computer-readable storage medium, the various methods described above may be performed.

[0313] In addition, the computer device may also include (but not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (eg, keyboard, mouse, speaker, etc.), etc.

[0314] The processor may communicate with external devices via an I / O bus via a wired or wireless network.

[0315] In one embodiment, the at least one computer executable instruction may also be compiled into or constitute a software product / computer program product, wherein one or more computer executable instructions are executed by a processor to perform the various functions and / or method steps in the embodiments described in the present technology.

[0316] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0317] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element limited by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0318] Although the embodiments disclosed in the present disclosure are as above, the above contents are only embodiments adopted for facilitating the understanding of the present disclosure and are not intended to limit the present disclosure. Any technician in the technical field to which the present disclosure belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present disclosure, but the scope of patent protection of the present disclosure shall still be subject to the scope defined in the attached claims.

Claims

1. A method for controlling a rail traction converter, characterized in that: include: Extract the steady-state quantity of the intermediate DC voltage of the track traction converter; Obtain the intermediate DC voltage after noise is filtered out; Calculating a given torque compensation amount on the motor side of the current switching cycle based on the steady-state amount of the intermediate DC voltage, the intermediate DC voltage after noise is filtered out, and the electrical angular velocity of the motor; Torque compensation is performed on the motor side based on the given torque compensation amount to suppress unbalanced traction current on the intermediate DC side.

2. The method according to claim 1, characterized in that The given torque compensation amount of the motor side in the current switching cycle is calculated based on the steady-state amount of the intermediate DC voltage, the intermediate DC voltage after noise filtering and the motor electrical angular velocity, using the following calculation formula: In the formula, Indicates the given torque compensation on the motor side, C indicates the intermediate support capacitor, U dc_st Represents the steady-state quantity of the intermediate DC voltage, U dc1 Represents the intermediate DC voltage after noise is filtered out, ω n represents the motor electrical angular velocity, T p Represents the switching cycle.

3. The method according to claim 1, characterized in that Also includes: In the indirect stator quantity control process, the angle increment of the stator flux in the current switching cycle is calculated, and the angle increment includes a steady-state increment angle and a dynamic increment angle; The dynamic incremental angle is calculated based on the given torque, the feedback torque, the maximum subversion torque at the previous moment and the maximum subversion torque at the current moment; According to the conversion relationship between the flux linkage and voltage, the stator side voltage component required for SVPWM modulation is obtained based on the angle increment, and then the magnetic field is controlled to run around the circular flux linkage trajectory.

4. The method according to claim 3, characterized in that The dynamic incremental angle is calculated using the following formula: In the formula, Δθ dyn Indicates the dynamic increment angle in the current switching cycle, δ k represents the stator-rotor flux angle at the current moment k, δ (k-1) represents the stator-rotor flux angle at the previous moment k-1, T e * Indicates the given torque, T e Represents feedback torque, T bk represents the maximum overturning torque at the current time k, T b(k-1) Represents the maximum overturning torque at the current time k-1.

5. The method according to claim 1, characterized in that The steady-state quantity of the intermediate DC voltage of the track traction converter is extracted by the following calculation formula: Where U dc_st Represents the steady-state quantity of the intermediate DC voltage of the traction converter, τ L1 represents the cutoff frequency of the first-order low-pass filter, and s represents the integral.

6. The method according to claim 1, characterized in that The intermediate DC voltage after noise filtering is obtained through an enhanced phase-locked loop.

7. The method according to claim 4, characterized in that The calculation formula of the dynamic incremental angle is obtained as follows: The first calculation formula of torque under stator flux and rotor flux is established as follows: Where, δ represents the stator-rotor flux angle; ψ s represents the stator flux; ψ r Represents the rotor flux; T e Indicates torque; P n Indicates the number of motor pole pairs; L σ It represents the Γ-type equivalent leakage inductance of asynchronous motor; The rotor flux is approximately obtained according to the following second calculation formula: |ψ r |=|ψ s |·cosδ Convert the second calculation formula into the following third calculation formula: When sin2δ=1, the maximum subversion torque of the system is obtained According to the second and third calculation formulas, the angle between the stator and rotor flux is calculated as In one switching cycle, T p The dynamic incremental angle calculation formula for torque regulation is: In the formula, Δθ dyn Indicates the dynamic increment angle in the current switching cycle, δ k represents the stator-rotor flux angle at the current moment k, δ (k-1) represents the stator-rotor flux angle at the previous moment k-1, T e * Indicates the given torque, T e Represents feedback torque, T bk represents the maximum overturning torque at the current time k, T b(k-1) Represents the maximum overturning torque at the current time k-1.

8. A rail traction converter, comprising a control unit, characterized in that: The control unit controls the track traction converter using the method according to any one of claims 1 to 7.

9. A track induced voltage test platform, characterized in that: It is used to test the transient induced voltage generated by the unbalanced traction current on both sides of the rail. The track induced voltage test platform includes: Two first aluminum tubes simulating rail impedance, with multiple test points arranged on the first aluminum tubes, for simulating the dynamic process of a train passing over a track circuit by continuously moving the test points under static conditions; Two second aluminum tubes simulating axle impedance are respectively overlapped with the two first aluminum tubes to form a closed loop; The resistor simulating the impedance of the axle-rail connection; The test cables are connected to the rails on both sides respectively; Simulate the impedance of the resonant unit in the track circuit; The traction system is placed above the closed loop, and the placement height and the relative layout and wiring of the sub-components of the traction system simulate the layout and wiring of the real vehicle at a 1:1 ratio. The traction system includes the rail traction inverter described in claim 8.

10. The rail induction voltage testing platform according to claim 9, characterized in that: It also includes a testing instrument, the testing frequency of which is set according to the working frequency band of the track circuit.

11. A method for testing track induced voltage, characterized in that: Based on the test platform according to claim 9 or 10, the track induced voltage test method comprises: Under different train operation modes, the worst working conditions of the corresponding track induced voltage are determined by testing respectively; Determine the worst working condition of the train track induced voltage based on the worst working condition of the track induced voltage under each train operation mode; Determine whether the track induced voltage corresponding to the worst working condition of the train track induced voltage meets the preset conditions: if the preset conditions are not met, it indicates that the track unbalanced traction current interferes with the track circuit of the train; Among them, the train operation modes include traction acceleration mode, resistance braking mode and regenerative braking mode, and the worst working conditions of the track induced voltage include voltage, torque, speed, open circuit / short circuit.

12. The rail induced voltage testing method according to claim 11, characterized in that: Before respectively testing and determining the worst working conditions of the corresponding track induced voltages under different train operation modes, the method further includes: After calibrating the test instrument, set it to the maximum hold mode; The test instrument is used to perform a background noise test, including testing the environmental noise when the traction system is not powered on, and, when the traction system is powered on, separating the test cable from the aluminum tube and then short-circuiting the test cable to test the interference of the cable's own coupling; When it is determined that the background noise meets the conditions, after the traction system is powered on, the steps of testing and determining the worst working conditions of the corresponding track induced voltage under different train operation modes are performed.

13. A train and axle counter electromagnetic compatibility test and evaluation system, characterized in that: include: The first test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under the first test bandwidth; The second test antenna is used to receive magnetic field signals emitted by the train in three directions of X, Y and Z under the second test bandwidth; The first test bandwidth is lower than the second test bandwidth; An acquisition system, used for continuously acquiring the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage; Data analysis system: Based on the analog voltage data collected by the acquisition system each time, it evaluates whether the train and the trackside axle counter meet the electromagnetic compatibility. If the train and the trackside axle counter do not meet the electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method described in any one of claims 1 to 7 to control the track traction inverter.

14. A method for testing and evaluating electromagnetic compatibility between a train and an axle counter, characterized in that: Based on the implementation of the train and axle counter electromagnetic compatibility test and evaluation system according to claim 13, the train and axle counter electromagnetic compatibility test and evaluation method comprises: The first test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a first test bandwidth; the second test antenna receives magnetic field signals emitted by trains in three directions of X, Y and Z under a second test bandwidth; the first test bandwidth is lower than the second test bandwidth; The acquisition system continuously acquires the magnetic field signals respectively received by the first test antenna and the second test antenna in the form of analog voltage; The data analysis system evaluates whether the train and the trackside axle counter meet the electromagnetic compatibility based on the analog voltage data collected by the acquisition system each time. If the train to be tested and the trackside axle counter do not meet the electromagnetic compatibility, it indicates that the unbalanced traction current of the track interferes with the trackside axle counter signal system. During the actual operation of the train, the control unit of the track traction inverter adopts the method described in any one of claims 1 to 7 to control the track traction inverter.

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