Parameter calculation method and device of permanent magnet traction motor

Abstract

The invention provides a parameter calculation method and device of a permanent magnet traction motor. The PHM board card is used for collecting the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the on-off state of the inverter and the intermediate voltage in the operation process of the traction converter of the motor train unit, so that the inductance, resistance and permanent magnet flux linkage of the permanent magnet traction motor of the motor train unit are monitored in real time, and other hardware facilities do not need to be added; according to the parameter observation scheme disclosed by the invention, the motor parameters can be quickly obtained according to the high-sampling-rate parameters, and an effective reference can be provided for motor state fault early warning.

Description

Technical Field

[0001] The present invention belongs to the technical field of permanent magnet traction of EMUs, and specifically relates to a parameter calculation method and device for a permanent magnet traction motor, electronic equipment, a computer-readable storage medium, and a computer program product. Background Art

[0002] Permanent magnet traction system has many advantages such as high power density, high efficiency, high power factor, low noise and energy saving. In recent years, it has also begun to be explored in urban rail, EMU and locomotives. With the continuous increase in the operating mileage and operating speed of high-speed rail, the travelable time and space span is constantly expanding. High-speed trains are in constant speed, starting, traction acceleration, braking deceleration and frequent switching of different states for a long time. They are also affected by external environments such as bad weather and natural disasters, and their service conditions are complex and changeable. As a key subsystem of the high-speed rail traction system, the health status of the traction motor directly affects the safe operation of the high-speed rail train set. As a complex electromechanical electromagnetic coupling system, the permanent magnets of the permanent magnet traction motor rotor are usually made of rare earth materials. In the train operation environment, high temperature, corrosion, oxidation and other harsh conditions can easily lead to irreversible demagnetization of the permanent magnet, thereby affecting the normal torque output of the traction motor.

[0003] With the continuous improvement of the intelligent requirements for rail vehicles, ensuring the safe and efficient operation of locomotives and vehicles and improving the system fault diagnosis, fault prediction and fault identification capabilities have become the overall requirements of intelligent applications. The fault prediction and health management (PHM) solutions for permanent magnet traction systems of different models clearly put forward the application requirements for permanent magnet traction motor status monitoring and fault warning.

[0004] In the existing solutions, the state monitoring of permanent magnet traction systems mainly focuses on the observation of motor flux. The method used is also obtained by dividing the reference voltage and the speed when the train is idling. This method can only perform state monitoring under special working conditions. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a parameter calculation method and device, a computer-readable storage medium and a computer program product capable of online real-time monitoring of a permanent magnet traction motor.

[0006] In order to achieve the above objectives, in a first aspect, an embodiment of the present disclosure provides a method for calculating parameters of a permanent magnet traction motor, comprising:

[0007] Collecting the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the on / off state of the inverter and the intermediate voltage during the operation of the traction converter;

[0008] reconstructing the three-phase voltage of the permanent magnet traction motor according to the switching state of the inverter and the intermediate voltage;

[0009] Determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase current, the three-phase voltage, and the decoded angle of the rotary transformer;

[0010] Based on the switching state of the inverter, in a set of steady-state switching states, at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer are selected according to a preset time interval;

[0011] Calculating the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motor;

[0012] Obtaining the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer;

[0013] When the current change rate is greater than a preset threshold, the parameters of the permanent magnet traction motor are calculated according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor.

[0014] In some embodiments, the three phases are phase a, phase b and phase c, and the three-phase voltage includes phase a voltage, phase b voltage and phase c voltage; according to the switching state of the inverter and the intermediate voltage, the three-phase voltage of the permanent magnet traction motor is reconstructed according to the following formula:

[0015]

[0016] Among them, Ua, Ub, Uc represent the phase voltage of phase a, phase voltage of phase b and phase voltage of phase c respectively, Sa, Sb, Sc represent the three switching states of the inverter corresponding to phase a, phase b and phase c respectively; Udc represents the intermediate voltage.

[0017] In some embodiments, the voltage of the permanent magnet traction motor includes an excitation component of the voltage and a torque component of the voltage; the current of the permanent magnet traction motor includes an excitation component of the current and a torque component of the current; the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor are calculated according to the following formula:

[0018]

[0019] Ud and Uq are the excitation component of the voltage and the torque component of the voltage respectively; Id and Iq are the excitation component of the current and the torque component of the voltage respectively; θr is the decoding angle of the rotary transformer; Ua, Ub, Uc are the three-phase voltages respectively, and Ia, Ib, Ic are the three-phase currents respectively.

[0020] In some embodiments, the current change rate includes a change rate of an excitation component of the current and a change rate of a torque component of the current; and calculating the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motors includes:

[0021] Calculating a first current difference between the excitation components of the current of each two adjacent groups of the at least three groups of the permanent magnet traction motors, and dividing the first current difference by the preset time interval to obtain a change rate of the excitation components of the current of the at least two groups of the permanent magnet traction motors;

[0022] Calculate the second current difference between the torque components of the current of each two adjacent groups among the torque components of the current of the at least three groups of permanent magnet traction motors, and divide the second current difference by the preset time interval to obtain the change rate of the torque components of the current of at least two groups of permanent magnet traction motors.

[0023] In some embodiments, obtaining the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of the rotary transformer decoding angles includes:

[0024] The rotational speed difference between every two adjacent groups of the rotary transformer decoding angles in the at least three groups of the rotary transformer decoding angles is calculated, and the rotational speed difference is divided by the preset time interval to obtain the electrical rotational speeds of at least two groups of the permanent magnet traction motors.

[0025] In some embodiments, the parameters of the permanent magnet traction motor include an excitation component of the inductance of the permanent magnet traction motor, a torque component of the inductance, a resistance of the permanent magnet traction motor, and a permanent magnet flux linkage;

[0026] When the current change rate is greater than a preset threshold, the parameters of the permanent magnet traction motor are calculated according to the following formula:

[0027]

[0028] Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d(k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

[0029] In a second aspect, the present disclosure further provides a parameter calculation device for a permanent magnet traction motor, the device comprising:

[0030] A collection module, used to collect the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the switching state of the inverter and the intermediate voltage during the operation of the traction converter;

[0031] A reconstruction module, configured to reconstruct the three-phase voltage of the permanent magnet traction motor according to the switching state of the inverter and the intermediate voltage;

[0032] A determination module, configured to determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase current, the three-phase voltage, and the decoded angle of the rotary transformer;

[0033] A selection module, configured to select at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer according to a preset time interval in a group of steady-state switching states based on the switching state of the inverter;

[0034] A first calculation module, configured to calculate a current change rate of the permanent magnet traction motor according to at least three selected groups of currents of the permanent magnet traction motor;

[0035] A second calculation module, configured to obtain the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer;

[0036] The third calculation module is used to calculate the parameters of the permanent magnet traction motor according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor when the current change rate is greater than a preset threshold.

[0037] In some embodiments, the parameters of the permanent magnet traction motor include the excitation component of the inductance of the permanent magnet traction motor, the torque component of the inductance, the resistance of the permanent magnet traction motor and the permanent magnet flux linkage; the third calculation module is specifically used to calculate the parameters of the permanent magnet traction motor according to the following formula when the current change rate is greater than a preset threshold:

[0038]

[0039] Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d (k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

[0040] In a third aspect, the present disclosure further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the computing method of the first aspect described above is implemented.

[0041] In a fourth aspect, the present disclosure further provides a computer-readable storage medium storing a computer program for executing the computing method of the first aspect.

[0042] In a fifth aspect, the present disclosure further provides a computer program product, including a computer program / instruction, which implements the steps of the computing method of the first aspect when the computer program / instruction is executed by a processor.

[0043] The present invention utilizes a PHM board to collect the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the on / off state of the inverter, and the intermediate voltage during the operation of the EMU traction converter to perform real-time monitoring of the inductance, resistance, and permanent magnet flux of the EMU permanent magnet traction motor. No other hardware facilities need to be added, thus saving system costs. The parameter observation scheme of the present invention can quickly obtain motor parameters based on high sampling rate parameters, which can serve as an effective reference for motor status fault warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a permanent magnet traction converter provided in an embodiment of the present disclosure;

[0046] Figure 2 A flow chart of a method for calculating parameters of a permanent magnet traction motor provided in an embodiment of the present disclosure;

[0047] Figure 3 A waveform diagram of the switching state of an inverter collected by a PHM according to an embodiment of the present disclosure;

[0048] Figure 4 A waveform diagram of a voltage of a permanent magnet traction motor and a current of the permanent magnet traction motor provided in an embodiment of the present disclosure;

[0049] Figure 5 A diagram of parameter observation results of a permanent magnet traction motor provided in an embodiment of the present disclosure;

[0050] Figure 6 A structural block diagram of a parameter calculation device for a permanent magnet traction motor provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail and completely in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0052] In a first aspect, an embodiment of the present disclosure provides a method for calculating parameters of a permanent magnet traction motor, which can be applied to a permanent magnet traction converter.

[0053] Figure 1 Schematic diagram of a permanent magnet traction converter provided by an embodiment of the present disclosure. Figure 1As shown, the permanent magnet traction converter includes a PHM (fault prediction and health management) board 50, a permanent magnet traction motor 10, an inverter 20, an intermediate link 30 and a rectifier 40. The PHM board 50 is respectively connected to the permanent magnet traction motor 10, the inverter 20, the intermediate link 30 and the rectifier 40, and is used to collect various parameters in the operation process of the traction converter in real time. Among them, the three-phase a phase, b phase and c phase of the permanent magnet traction motor 10 are respectively connected to the a end, b end and c end of the inverter 20, and the inverter 20 has three groups of switch states: Sa, Sb, Sc. The various parameters in the operation process of the traction converter include but are not limited to the three-phase currents Ia, Ib and Ic of the permanent magnet traction motor 10, the rotary transformer decoding angle θr collected according to the rotary transformer signal of the permanent magnet traction motor 10, the switch states of the inverter: Sa, Sb and Sc, the intermediate voltage Udc and the rectifier switch states: S1 and S2. Among them, academically, the voltage between the positive and negative busbars is called the intermediate voltage Udc.

[0054] It is understandable that if Figure 1 As shown, the permanent magnet traction converter also includes a transformer, a contact network, a decoding chip, etc., which are also connected to the PHM board 50. The PHM board 50 can also collect the grid-side voltage Unet of the contact network and the grid-side current Inet of the transformer end, which will not be described in detail.

[0055] Figure 2 A flow chart of a method for calculating parameters of a permanent magnet traction motor provided in an embodiment of the present disclosure, which method can be applied to the above Figure 1 Permanent magnet traction converter in. Figure 1-2 As shown, the parameter calculation method specifically includes:

[0056] S1. Collect the three-phase currents Ia, Ib, Ic of the permanent magnet traction motor, the decoding angle θr of the rotary transformer, the switching states Sa, Sb, Sc of the inverter, and the intermediate voltage Udc during the operation of the traction converter.

[0057] Specifically, the PHM board 50 utilizes its high-precision acquisition characteristics to accurately acquire various state parameters during the operation of the traction converter.

[0058] S2. Reconstruct the three-phase voltages Ua, Ub, and Uc of the permanent magnet traction motor according to the switching states Sa, Sb, and Sc of the inverter and the intermediate voltage Udc.

[0059] Specifically, when observing the parameters of the permanent magnet traction motor 10, three-phase voltage is required. However, due to the high cost of voltage sensor components, only current sensors are provided in the inverter 20, and voltage sensors are generally not provided. Among them, the three-phase voltage of the permanent magnet traction motor 10 is closely related to the switching state of the inverter 20. The embodiment of the present disclosure can accurately reconstruct the three-phase voltage of the permanent magnet traction motor 10 based on the switching state and intermediate voltage of the inverter accurately collected by the PHM board 50.

[0060] S3. Determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase currents Ia, Ib and Ic, the three-phase voltages Ua, Ub, Uc, and the decoding angle θr of the rotary transformer.

[0061] Specifically, the voltage of the permanent magnet traction motor includes the excitation component Ud of the voltage and the torque component Uq of the voltage; the current of the permanent magnet traction motor includes the excitation component Id of the current and the torque component Iq of the current. Among them, the excitation component (iD) mainly controls the magnetic field of the motor, is parallel to the rotor magnetic field, and represents the excitation current of the motor. The adjustment of the excitation component can be achieved by changing the magnitude and direction of the excitation current, thereby affecting the torque and efficiency of the motor. The torque component (iQ) is mainly responsible for generating torque and is perpendicular to the rotor magnetic field. The adjustment of the torque component is achieved by changing the magnitude and direction of the torque current, which in turn affects the load capacity and operating efficiency of the motor. This distinction makes the motor control more refined. By independently controlling the excitation component and the torque component, more efficient energy conversion and better motor performance can be achieved. In vector control (FOC), this distinction is particularly important because it allows more precise control of the motor to achieve the required torque and speed.

[0062] S4. Based on the switching state of the inverter, in a set of steady-state switching states, at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angles θr(k), θr(k+1), and θr(k+2) of the rotary transformer are selected according to a preset time interval Δt.

[0063] Specifically, at least three groups of voltages of the permanent magnet traction motor are selected, including at least three groups of voltage excitation components Ud(k), Ud(k+1), Ud(k+2) and voltage torque components Uq(k), Uq(k+1), Uq(k+2); at least three groups of currents of the permanent magnet traction motor are selected, including at least three groups of current excitation components Id(k), Id(k+1), Id(k+2) and current torque components Iq(k), Iq(k+1), Iq(k+2), wherein k, k+1, k+2 are respectively three selected moments.

[0064] S5. Calculate the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motor.

[0065] Specifically, the current change rate of the permanent magnet traction motor includes the change rate of the excitation component of the current and the change rate of the torque component of the current. According to the three groups of currents of the permanent magnet traction motor, the change rates of the excitation components of the two groups of currents ΔId(k), ΔId(k+1) and the change rates of the torque components of the two groups of currents ΔIq(k), ΔIq(k+1) can be obtained.

[0066] The voltage and current change rates on the output side of the converter determine the back EMF of the current, and the back EMF of the current can be estimated by calculating the change rate of the current.

[0067] In the prior art, a DSP chip is usually used to sample the current change rate, and the sampling method in the prior art makes the accuracy of the sampling result low. Compared with the prior art, the embodiment of the present disclosure can collect high-frequency information through the high-speed collection characteristics of the PHM board 50, and infer the back electromotive force of the current through the collected high-frequency information, so that the final current back electromotive force is more accurate.

[0068] S6. Obtain the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer.

[0069] Specifically, the three groups of rotary transformer decoding angles can obtain the electrical rotation speeds ω(k) and ω(k+1) of the two groups of permanent magnet traction motors.

[0070] S7. When the current change rate is greater than a preset threshold, the parameters of the permanent magnet traction motor are calculated according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor.

[0071] Specifically, the embodiment of the present disclosure is obtained through real-time calculation, therefore, the current change rate should not be too small. If the current change rate is too small, a large error may be introduced in the real-time calculation process, which will eventually affect the accuracy of the parameter calculation of the permanent magnet traction motor. Among them, the preset threshold can be determined according to the selected preset time interval Δt, and of course it can also be determined according to other factors, and the embodiment of the present disclosure does not limit this. The embodiment of the present disclosure compares the rate of change of the current with the preset threshold, and calculates the parameters of the permanent magnet traction motor based on the comparison result, which can ensure that in the process of calculating the parameters of the permanent magnet traction motor, the selected voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer are valid, thereby improving the accuracy of the calculation.

[0072] The disclosed embodiment uses the PHM board to accurately collect various parameters of the permanent magnet traction converter, and the collected parameters can be used to reconstruct an accurate three-phase voltage. Further, based on the real-time collected three-phase current, the decoded angle of the rotary transformer and the reconstructed three-phase voltage, the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor can be accurately calculated, and then the current change rate can be further calculated based on the current of the permanent magnet traction motor. Finally, the parameters of the permanent magnet traction motor are calculated based on the current change rate, the electric speed and the voltage of the permanent magnet traction motor.

[0073] The present invention uses the PHM board to collect the three-phase current of the permanent magnet traction motor during the operation of the EMU traction converter, the decoding angle of the rotary transformer, the switch state of the inverter and the intermediate voltage to monitor the inductance, resistance and permanent magnet flux of the permanent magnet traction motor of the EMU in real time, without adding other hardware facilities, saving system costs, and ensuring both real-time and accuracy. The parameter calculation scheme disclosed in the present invention can quickly obtain the parameters of the permanent magnet traction motor according to the high sampling rate parameters, which can serve as an effective reference for the motor state fault warning of the permanent magnet traction motor.

[0074] In some embodiments, in step S2, the three phases are phase a, phase b and phase c, and the three-phase voltages include phase a voltage Ua, phase b voltage Ub and phase c voltage Uc; according to the switching state of the inverter and the intermediate voltage, the three-phase voltage of the permanent magnet traction motor is reconstructed according to the following formula:

[0075] Among them, Ua, Ub, Uc represent the phase voltage of phase a, phase voltage of phase b and phase voltage of phase c respectively, Sa, Sb, Sc represent the three switching states of the inverter corresponding to phase a, phase b and phase c respectively; Udc represents the intermediate voltage.

[0076] Figure 3 The waveform diagram of the switching state of the inverter collected by a PHM according to an embodiment of the present disclosure is shown in FIG. Figure 3 As shown in FIG. 1 , the switch state of the inverter includes three groups of switch states Sa, Sb, and Sc corresponding to the three, respectively. When the switch state is 0, it means that the switch state corresponding to the inverter is "off", and when it is 1, it means that the switch state corresponding to the inverter is "on". Figure 3 It can be seen that the phase difference between the three switching states of Sa, Sb and Sc is 120°.

[0077] It is understandable that the embodiments of the present disclosure may also reconstruct the three-phase voltage in other ways, and the present disclosure is not limited to this.

[0078] In some embodiments, the voltage of the permanent magnet traction motor includes an excitation component Ud of the voltage and a torque component Uq of the voltage; the current of the permanent magnet traction motor includes an excitation component Id of the current and a torque component Iq of the current; step S3 specifically includes calculating the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the following formula:

[0079]

[0080] Ud and Uq are the excitation component of the voltage and the torque component of the voltage respectively; Id and Iq are the excitation component of the current and the torque component of the voltage respectively; θr is the decoding angle of the rotary transformer; Ua, Ub, Uc are the three-phase voltages respectively, and Ia, Ib, Ic are the three-phase currents respectively.

[0081] Figure 4 The following is a waveform diagram of a voltage of a permanent magnet traction motor and a current of the permanent magnet traction motor provided by an embodiment of the present disclosure. Figure 4 As shown, the relationship between the excitation component and the excitation component of the voltage and current can be obtained more intuitively based on the waveform diagram.

[0082] In some embodiments, step S5, calculating the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motors, comprises:

[0083] Calculating a first current difference between the excitation components of the current of each two adjacent groups of the excitation components Id(k), Id(k+1), and Id(k+2) of the current of the at least three groups of permanent magnet traction motors, and dividing the first current difference by the preset time interval Δt to obtain the excitation component change rates ΔId(k) and ΔId(k+1) of the current of the at least two groups of permanent magnet traction motors;

[0084] The second current difference of the torque components of the current of each two adjacent groups of the torque components of the current of the at least three groups of the permanent magnet traction motors Iq(k), Iq(k+1), and Iq(k+2) is calculated, and the second current difference is divided by the preset time interval Δt to obtain the torque component change rates ΔIq(k) and ΔIq(k+1) of the current of the at least two groups of the permanent magnet traction motors. That is:

[0085] Among them, ΔId and ΔIq are the change rates of the excitation component of the current of the permanent magnet traction motor and the change rate of the matrix component of the current, respectively, k, k+1, and k+2 are three selected moments, and Δt is a preset time interval.

[0086] In some embodiments, step S6, obtaining the electrical speed of the permanent magnet traction motor according to the selected at least three groups of the rotary transformer decoding angles θr(k), θr(k+1), and θr(k+2), comprises:

[0087] Calculate the speed difference of the rotary transformer decoding angles of each two adjacent groups of the at least three groups of rotary transformer decoding angles θr(k), θr(k+1), and θr(k+2), and divide the speed difference by the preset time interval Δt to obtain the electrical speeds ω(k) and ω(k+1) of at least two groups of permanent magnet traction motors. That is:

[0088]

[0089] In some embodiments, the parameters of the permanent magnet traction motor include the excitation component Ld of the inductance of the permanent magnet traction motor, the torque component Lq of the inductance, the resistance R of the permanent magnet traction motor, and the permanent magnet flux linkage Ψr. Step S7 specifically includes: when the current change rate is greater than a preset threshold, calculating the parameters of the permanent magnet traction motor according to the following formula:

[0090]

[0091] Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d (k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

[0092] In some embodiments, before executing step S7, it also includes: determining whether the current change rate is greater than a preset threshold value to obtain a determination result; when the determination result is that the current change rate is greater than the preset threshold value, executing step S7.

[0093] Specifically, the parameters of the permanent magnet traction motor in the embodiment of the present disclosure are obtained by real-time calculation, so the current change rate should not be too small. If the current change rate is too small, a large error may be introduced in the real-time calculation process, which will eventually affect the accuracy of the parameter calculation of the permanent magnet traction motor. Only when |ΔId(k)|, |ΔId(k+1)|, |ΔIq(k)|, |ΔIq(k+1)| are all greater than the preset threshold value Ilim, the Ld, Lq, R, Ψr parameters of the permanent magnet traction motor calculated according to step S7 are accurate.

[0094] Figure 5 A diagram of parameter observation results of a permanent magnet traction motor provided in an embodiment of the present disclosure.

[0095] In some embodiments, the method further includes: based on the calculated parameters of the permanent magnet traction motor, issuing an early warning for the state fault of the permanent magnet traction motor. Compared with the state monitoring of the permanent magnet traction system in the prior art, which focuses more on the observation of the motor flux, the method selected is also obtained by dividing the reference voltage and the speed when the train is idling. The methods in the prior art can only perform state monitoring under special working conditions. The method proposed in the present disclosure utilizes the high-precision acquisition characteristics of PHM to obtain the real-time voltage and current of the permanent magnet traction motor, and calculates the parameters of the permanent magnet traction motor in real time based on the real-time obtained voltage and current, and performs parameter observation based on the calculated parameters of the permanent magnet traction motor. The observation results can be found in Figure 5 , and its observation results are guaranteed in real time and accuracy.

[0096] The present invention utilizes the PHM board to collect the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the switching state of the inverter and the intermediate voltage during the operation of the EMU traction converter to monitor the inductance, resistance and permanent magnet flux of the EMU permanent magnet traction motor in real time without adding other hardware facilities, thus saving system costs. The parameter observation scheme of the present invention can quickly obtain motor parameters based on high sampling rate parameters, which can serve as an effective reference for motor status fault warning.

[0097] On the second aspect, based on the same inventive concept, the embodiments of the present disclosure also provide a parameter calculation device for a permanent magnet traction motor.

[0098] Figure 6 This is a structural block diagram of a parameter calculation device for a permanent magnet traction motor provided by an embodiment of the present disclosure. Figure 6 As shown, the device 600 includes a collection module 610 , a reconstruction module 620 , a determination module 630 , a selection module 640 , a first calculation module 650 , a second calculation module 660 and a third calculation module 670 .

[0099] Among them, the acquisition module 610 is used to collect the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the switching state of the inverter and the intermediate voltage during the operation of the traction converter.

[0100] The reconstruction module 620 is used to reconstruct the three-phase voltage of the permanent magnet traction motor according to the switching state of the inverter and the intermediate voltage.

[0101] The determination module 630 is used to determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase current, the three-phase voltage, and the decoding angle of the rotary transformer.

[0102] The selection module 640 is used to select at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer according to a preset time interval in a group of steady-state switching states based on the switching state of the inverter.

[0103] The first calculation module 650 is used to calculate the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motor.

[0104] The second calculation module 660 is used to obtain the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer.

[0105] The third calculation module 670 is used to calculate the parameters of the permanent magnet traction motor according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor when the current change rate is greater than a preset threshold.

[0106] In some embodiments, the reconstruction module 620 reconstructs the three-phase voltages Ua, Ub, and Uc according to the following formulas:

[0107]

[0108] In some embodiments, the determination module 630 calculates the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor specifically according to the following formula:

[0109]

[0110] Ud and Uq are the excitation component of the voltage and the torque component of the voltage respectively; Id and Iq are the excitation component of the current and the torque component of the voltage respectively; θr is the decoding angle of the rotary transformer; Ua, Ub, Uc are the three-phase voltages respectively, and Ia, Ib, Ic are the three-phase currents respectively.

[0111] In some embodiments, the first calculation module 650 is specifically used to calculate the first current difference of the excitation components of the current of each two adjacent groups among the excitation components Id(k), Id(k+1), and Id(k+2) of the current of the at least three groups of the permanent magnet traction motors, and divide the first current difference by the preset time interval Δt to obtain the excitation component change rates ΔId(k) and ΔId(k+1) of the current of the at least two groups of the permanent magnet traction motors;

[0112] The second current difference of the torque components of the current of each two adjacent groups of the torque components of the current of the at least three groups of the permanent magnet traction motors Iq(k), Iq(k+1), and Iq(k+2) is calculated, and the second current difference is divided by the preset time interval Δt to obtain the torque component change rates ΔIq(k) and ΔIq(k+1) of the current of the at least two groups of the permanent magnet traction motors. That is:

[0113] Among them, ΔId and ΔIq are the change rates of the excitation component of the current of the permanent magnet traction motor and the change rate of the matrix component of the current, respectively, k, k+1, and k+2 are three selected moments, and Δt is a preset time interval.

[0114] In some embodiments, the second calculation module 660 is specifically used to calculate the speed difference of the rotary transformer decoding angles of each two adjacent groups of the at least three groups of rotary transformer decoding angles θr(k), θr(k+1), and θr(k+2), and divide the speed difference by the preset time interval Δt to calculate the electrical speeds ω(k) and ω(k+1) of at least two groups of permanent magnet traction motors. That is:

[0115]

[0116] In some embodiments, the third calculation module 670 is specifically configured to calculate the parameters of the permanent magnet traction motor according to the following formula when the current change rate is greater than a preset threshold:

[0117]

[0118] Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d(k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

[0119] In some embodiments, the computing device 600 further includes a judgment module for judging whether the current change rate is greater than a preset threshold value. Only when the judgment result is that |ΔId(k)|, |ΔId(k+1)|, |ΔIq(k)|, |ΔIq(k+1)| are all greater than the preset threshold value Ilim, the Ld, Lq, R, Ψr parameters of the permanent magnet traction motor calculated by the third computing module 670 are accurate.

[0120] In some embodiments, the computing device 600 further includes a prediction module for providing an early warning of a state fault of the permanent magnet traction motor based on the parameters of the permanent magnet traction motor calculated by the third computing module 670 .

[0121] It can be understood that the specific details of the device provided in the embodiment of the present disclosure can refer to the specific details of the calculation method embodiment of the first aspect mentioned above, and will not be repeated here.

[0122] In a third aspect, an embodiment of the present disclosure further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described in any one of the first aspects is implemented.

[0123] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program of the method described in any one of the first aspects above.

[0124] In a fifth aspect, an embodiment of the present disclosure further provides a computer program product, comprising a computer program / instructions, which, when executed by a processor, implement the steps of any one of the methods described in the first aspect above.

[0125] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0126] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0127] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0128] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0129] The present disclosure uses specific embodiments to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method of the present disclosure and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present disclosure, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present disclosure.

Claims

1. A method for calculating parameters of a permanent magnet traction motor, characterized in that: The method comprises: Collecting the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the switching state of the inverter and the intermediate voltage during the operation of the traction converter; reconstructing the three-phase voltage of the permanent magnet traction motor according to the switching state of the inverter and the intermediate voltage; Determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase current, the three-phase voltage, and the decoded angle of the rotary transformer; Based on the switching state of the inverter, in a set of steady-state switching states, at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer are selected according to a preset time interval; Calculating the current change rate of the permanent magnet traction motor according to the selected at least three groups of currents of the permanent magnet traction motor; Obtaining the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer; When the current change rate is greater than a preset threshold, the parameters of the permanent magnet traction motor are calculated according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor.

2. The method according to claim 1, characterized in that The three phases of the permanent magnet traction motor are phase a, phase b and phase c, respectively, and the three-phase voltage includes phase a voltage, phase b voltage and phase c voltage; according to the switching state of the inverter and the intermediate voltage, the three-phase voltage of the permanent magnet traction motor is reconstructed according to the following formula: Among them, Ua, Ub, Uc represent the phase voltage of phase a, phase voltage of phase b and phase voltage of phase c respectively, Sa, Sb, Sc represent the three switching states of the inverter corresponding to phase a, phase b and phase c respectively; Udc represents the intermediate voltage.

3. The method according to claim 1, characterized in that The voltage of the permanent magnet traction motor includes an excitation component of the voltage and a torque component of the voltage; the current of the permanent magnet traction motor includes an excitation component of the current and a torque component of the current; The voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor are calculated according to the following formula: Among them, Ud and Uq are the excitation component of the voltage and the torque component of the voltage respectively; Id and Iq are the excitation component of the current and the torque component of the voltage respectively; θr is the decoding angle of the rotary transformer; Ua, Ub, and Uc are the three-phase voltages respectively, and Ia, Ib, and Ic are the three-phase currents respectively.

4. The method according to claim 3, characterized in that The current change rate includes the change rate of the excitation component of the current and the change rate of the torque component of the current; the current change rate of the permanent magnet traction motor is calculated according to the current of at least three groups of permanent magnet traction motors selected, including: Calculating a first current difference between the excitation components of the current of each two adjacent groups of the at least three groups of the permanent magnet traction motors, and dividing the first current difference by the preset time interval to obtain a change rate of the excitation components of the current of the at least two groups of the permanent magnet traction motors; Calculate the second current difference between the torque components of the current of each two adjacent groups among the torque components of the current of the at least three groups of permanent magnet traction motors, and divide the second current difference by the preset time interval to obtain the change rate of the torque components of the current of at least two groups of permanent magnet traction motors.

5. The method according to claim 1, characterized in that: Obtaining the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of rotary transformer decoding angles, including: The rotational speed difference between every two adjacent groups of the rotary transformer decoding angles in the at least three groups of the rotary transformer decoding angles is calculated, and the rotational speed difference is divided by the preset time interval to obtain the electrical rotational speeds of at least two groups of the permanent magnet traction motors.

6. The method according to claim 1, characterized in that The parameters of the permanent magnet traction motor include the excitation component of the inductance of the permanent magnet traction motor, the torque component of the inductance, the resistance of the permanent magnet traction motor and the permanent magnet flux linkage; when the current change rate is greater than the preset threshold, the parameters of the permanent magnet traction motor are calculated according to the following formula: Wherein, Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d (k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

7. A parameter calculation device for a permanent magnet traction motor, characterized in that: The device comprises: A collection module, used to collect the three-phase current of the permanent magnet traction motor, the decoding angle of the rotary transformer, the switching state of the inverter and the intermediate voltage during the operation of the traction converter; A reconstruction module, configured to reconstruct the three-phase voltage of the permanent magnet traction motor according to the switching state of the inverter and the intermediate voltage; A determination module, configured to determine the voltage of the permanent magnet traction motor and the current of the permanent magnet traction motor according to the three-phase current, the three-phase voltage, and the decoded angle of the rotary transformer; A selection module, configured to select at least three groups of the voltage of the permanent magnet traction motor, the current of the permanent magnet traction motor, and the decoding angle of the rotary transformer according to a preset time interval in a group of steady-state switching states based on the switching state of the inverter; A first calculation module, configured to calculate a current change rate of the permanent magnet traction motor according to at least three selected groups of currents of the permanent magnet traction motor; A second calculation module, configured to obtain the electrical rotation speed of the permanent magnet traction motor according to the selected at least three groups of decoding angles of the rotary transformer; The third calculation module is used to calculate the parameters of the permanent magnet traction motor according to the current change rate, the electric speed and the voltage of the permanent magnet traction motor when the current change rate is greater than a preset threshold.

8. The device according to claim 7, characterized in that The parameters of the permanent magnet traction motor include the excitation component of the inductance of the permanent magnet traction motor, the torque component of the inductance, the resistance of the permanent magnet traction motor and the permanent magnet flux linkage; The third calculation module is specifically configured to calculate the parameters of the permanent magnet traction motor according to the following formula when the current change rate is greater than a preset threshold: Wherein, Ld and Lq are the excitation component and torque component of the inductance of the permanent magnet traction motor respectively; R is the resistance of the permanent magnet traction motor, Ψr is the permanent magnet flux; ΔI d (k), ΔI d (k+1) are the rates of change of the excitation component of the current at time k and time k+1 respectively; ΔIq(k) and ΔIq(k+1) are the rates of change of the torque component of the current at time k and time k+1 respectively; ω(k) and ω(k+1) are the electrical speeds of the permanent magnet traction motor at time k and time k+1 respectively; Ud(k) and Ud(k+1) are the excitation components of the voltage at time k and time k+1 respectively; Uq(k) and Uq(k+1) are the torque components of the voltage at time k and time k+1 respectively; Id(k) and Id(k+1) are the excitation components of the current at time k and time k+1 respectively; Iq(k) and Iq(k+1) are the torque components of the current at time k and time k+1 respectively.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method according to any one of claims 1 to 6.

11. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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