Parameter calculation method and device for permanent magnet traction motor

Abstract

The present disclosure provides a parameter calculation method and device of a permanent magnet traction motor. The present disclosure uses a PHM board to collect the three-phase current of the permanent magnet traction motor in the operation process of the motor train unit traction converter, the resolver decoding angle, the switch state of the inverter and the intermediate voltage to monitor the inductance, resistance and permanent magnet flux of the motor train unit permanent magnet traction motor in real time, without adding other hardware facilities, saving the system cost. The parameter observation scheme of the present disclosure can quickly obtain the motor parameters according to the high sampling rate parameters, and can effectively reference the motor state fault warning.

Description

Technical Field

[0001] The present disclosure 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, an electronic device, a computer-readable storage medium, and a computer program product. Background Art

[0002] Permanent magnet traction systems, due to their numerous advantages, including high power density, high efficiency, high power factor, low noise, and energy efficiency, have seen exploratory deployment in urban rail transit, EMUs, and locomotives in recent years. As high-speed rail operating mileage and speeds continue to increase, the travelable time and space span continues to expand. High-speed trains are constantly operating in constant speed, starting, traction acceleration, braking deceleration, and frequently switching between these states. Furthermore, they are subject to complex and variable operating conditions, often influenced by external environments such as severe weather and natural disasters. As a key subsystem of high-speed rail traction systems, the health of traction motors directly impacts the safe operation of high-speed trainsets. As a complex electromechanical and electromagnetically coupled system, the permanent magnets in permanent magnet traction motor rotors are typically made of rare earth materials. In the train operating environment, harsh operating conditions such as high temperature, corrosion, and oxidation can easily lead to irreversible demagnetization of the permanent magnets, thereby affecting the normal torque output of the traction motors.

[0003] With the increasing demand for intelligent rail vehicles, ensuring operational safety and efficiency, and improving system fault diagnosis, prediction, and identification capabilities have become overarching requirements for intelligent applications. The Prognostic Health Management (PHM) solutions for permanent magnet traction systems on various vehicle models clearly address the need for permanent magnet traction motor condition monitoring and fault warning.

[0004] In the existing solutions, the status monitoring of permanent magnet traction systems mainly focuses on the observation of motor flux. The method used is also to obtain the reference voltage by dividing the speed when the train is idling. This method can only be used for status 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 provide 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] 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] determining 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 sets 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 a 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 decoded 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 voltages include phase a voltage, phase b voltage, and phase c voltage. The three-phase voltages of the permanent magnet traction motor are reconstructed according to the switching state of the inverter and the intermediate voltage according to the following formula:

[0015]

[0016] Among them, Ua, Ub, and Uc represent the phase voltage of phase a, phase b, and phase c respectively, Sa, Sb, and 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, and Uc are the three-phase voltages respectively, and Ia, Ib, and 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 based on 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 currents 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 rate of change of the excitation components of the currents 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 of 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 component of the current of the at least two groups of permanent magnet traction motors.

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

[0024] The rotational speed difference between the rotational transformer decoding angles of each two adjacent groups in the at least three groups of the rotational transformer decoding angles is calculated, and the rotational speed difference is divided by the preset time interval to obtain the electrical rotational speeds of the 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 electric 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] An acquisition module 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;

[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, based on the switching state of the inverter, 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 in a set of steady-state switching states at preset time intervals;

[0034] a first calculation module, configured to calculate a 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;

[0035] a second calculation module, configured to obtain the electric speed of the permanent magnet traction motor according to the selected at least three groups of decoded 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 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:

[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 electric 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 the processor implements the computing method of the first aspect when executing the program.

[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, comprising 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 disclosure 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 status 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 disclosed in the present disclosure 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 following briefly introduces the drawings required for describing the embodiments. 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 by 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 showing parameter observation results of a permanent magnet traction motor provided by 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] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention is further described in detail and completely below with reference to the accompanying drawings and specific embodiments. It is apparent that the embodiments described are only a portion of the embodiments of the present disclosure, and not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative effort 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 (Prognostic 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 connected to the permanent magnet traction motor 10, the inverter 20, the intermediate link 30, and the rectifier 40, respectively, to collect various parameters during the operation of the traction converter in real time. The three phases a, b, and c of the permanent magnet traction motor 10 are connected to terminals a, b, and c of the inverter 20, respectively. The inverter 20 has three switching states: Sa, Sb, and Sc. The various parameters during the operation 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 resolver decoded angle θr collected based on the resolver signals of the permanent magnet traction motor 10, the inverter switching states: Sa, Sb, and Sc, the intermediate voltage Udc, and the rectifier switching 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 at the transformer end, which will not be described in detail.

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

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

[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 performing parameter observation of the permanent magnet traction motor 10, three-phase voltage is needed, but due to the high cost of voltage sensor elements, current sensors are generally provided in the inverter 20, and voltage sensors are generally not provided. The three-phase voltage of the permanent magnet traction motor 10 is closely related to the switching state of the inverter 20, and the three-phase voltage of the permanent magnet traction motor 10 can be accurately reconstructed based on the switching state and intermediate voltage of the inverter accurately collected by the PHM board card 50.

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

[0061] Specifically, 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. 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 realized by changing the size 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, which is perpendicular to the rotor magnetic field. The adjustment of the torque component is realized by changing the size and direction of the torque current, thereby affecting the load capacity and operating efficiency of the motor. This distinction makes motor control more refined, and 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 desired torque and speed.

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

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

[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. Based on the three sets of currents of the permanent magnet traction motor, the excitation component change rates ΔId(k) and ΔId(k+1) of the two sets of currents and the torque component change rates ΔIq(k) and ΔIq(k+1) of the two sets of currents can be obtained.

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

[0067] In the prior art, DSP chips are typically used to sample the current rate of change. This sampling method in the prior art results in low accuracy. Compared to the prior art, the present embodiment utilizes the high-speed acquisition characteristics of the PHM board 50 to collect high-frequency information. This high-frequency information can be used to infer the current back EMF, making the resulting current back EMF more accurate.

[0068] S6. Obtain the electrical rotational 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 transformers decode angles to 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, 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.

[0071] Specifically, the embodiment of the present disclosure is obtained through 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. 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. The embodiment of the present disclosure does not limit this. The embodiment of the present disclosure calculates the parameters of the permanent magnet traction motor based on the comparison result by comparing the current change rate with the preset threshold. It can ensure that in the process of calculating the parameters of the permanent magnet traction motor, the selected permanent magnet traction motor voltage, the permanent magnet traction motor current, and the rotary transformer decoding angle are valid, thereby improving the accuracy of the calculation.

[0072] The disclosed embodiments utilize a PHM board to accurately acquire various parameters of the permanent magnet traction converter. These acquired parameters can be used to reconstruct accurate three-phase voltages. Furthermore, based on the real-time acquired three-phase current, the decoded angle of the resolver, and the reconstructed three-phase voltage, the voltage and current of the permanent magnet traction motor can be accurately calculated. The rate of change of the current can then be calculated based on the current of the permanent magnet traction motor. Finally, the parameters of the permanent magnet traction motor can be calculated based on the current rate of change, the electrical speed, and the voltage of the permanent magnet traction motor.

[0073] This disclosure utilizes a PHM board to collect the three-phase current, resolver decoding angle, inverter switching state, and intermediate voltage of the permanent magnet traction motor during EMU traction converter operation. This allows for real-time monitoring of the inductance, resistance, and permanent magnet flux of the motor, eliminating the need for additional hardware, saving system costs and ensuring both real-time performance and accuracy. The disclosed parameter calculation scheme can rapidly acquire the parameters of the permanent magnet traction motor based on high-sampling-rate parameters, providing an effective reference for early warning of motor status faults.

[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. Based on the switching state of the inverter and the intermediate voltage, the three-phase voltages of the permanent magnet traction motor are reconstructed according to the following formula:

[0075] Among them, Ua, Ub, and Uc represent the phase voltage of phase a, phase b, and phase c respectively, Sa, Sb, and 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 This is a waveform diagram of the switching state of an inverter collected by a PHM according to an embodiment of the present disclosure. Figure 3 As shown in FIG, the switching state of the inverter includes three groups of switching states: Sa, Sb, and Sc, which correspond to the three. When the switching state is 0, it means that the switching state of the inverter is "off", and when it is 1, it means that the switching state of 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 does not limit 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, and Uc are the three-phase voltages respectively, and Ia, Ib, and Ic are the three-phase currents respectively.

[0081] Figure 4 The waveform diagram of the voltage and current of a permanent magnet traction motor provided by the embodiment of the present disclosure is shown in FIG. 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 this waveform diagram.

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

[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 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] Calculate the second current difference between the torque components of the current of each two adjacent groups of the torque components Iq(k), Iq(k+1), and Iq(k+2) of the at least three groups of permanent magnet traction motors, and divide the second current difference 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 permanent magnet traction motors. That is:

[0085] Among them, ΔId and ΔIq are the change rates of the excitation component and the matrix component of the current of the permanent magnet traction motor 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 sets of the rotary transformer decoding angles θr(k), θr(k+1), and θr(k+2), includes:

[0087] Calculate the speed difference between 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 the 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 permanent magnet traction motor's inductance, 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 electric 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, the method further 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 disclosed embodiment are calculated in real time. Therefore, the current rate of change should not be too small. If the current rate of change is too small, a large error may be introduced during the real-time calculation process, ultimately affecting the accuracy of the permanent magnet traction motor parameter calculation. The permanent magnet traction motor parameters Ld, Lq, R, and Ψr calculated in step S7 are accurate only when |ΔId(k)|, |ΔId(k+1)|, |ΔIq(k)|, and |ΔIq(k+1)| are all greater than a preset threshold value Ilim.

[0094] Figure 5 A diagram showing 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 of 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 method 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 a 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 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 disclosed in 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 embodiment of the present disclosure also provides 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 apparatus 600 includes an acquisition 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] The acquisition module 610 is used to acquire 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 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.

[0101] The determination module 630 is 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.

[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 based on the switching state of the inverter in a set of steady-state switching states according to a preset time interval.

[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 electric 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, and Uc are the three-phase voltages respectively, and Ia, Ib, and Ic are the three-phase currents respectively.

[0111] In some embodiments, the first calculation module 650 is specifically configured to calculate 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 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 permanent magnet traction motors;

[0112] Calculate the second current difference between the torque components of the current of each two adjacent groups of the torque components Iq(k), Iq(k+1), and Iq(k+2) of the at least three groups of permanent magnet traction motors, and divide the second current difference 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 permanent magnet traction motors. That is:

[0113] Among them, ΔId and ΔIq are the change rates of the excitation component and the matrix component of the current of the permanent magnet traction motor 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 between 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 the 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 electric 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 determination module configured to determine whether the current change rate is greater than a preset threshold. The Ld, Lq, R, and Ψr parameters of the permanent magnet traction motor calculated by the third computing module 670 are accurate only if the determination result indicates that |ΔId(k)|, |ΔId(k+1)|, |ΔIq(k)|, and |ΔIq(k+1)| are all greater than a preset threshold Ilim.

[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 the processor implements any one of the methods described in the first aspect when executing the computer program.

[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 any one of the methods described in the first aspect.

[0124] In a fifth aspect, an embodiment of the present disclosure further provides a computer program product, comprising a computer program / instruction, which, when executed by a processor, implements 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. Furthermore, 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 magnetic 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 produce 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 that can direct a computer or other programmable data processing device to work 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 The 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 operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device 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] Specific embodiments are used in the present disclosure 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 and core ideas of the present disclosure. At the same time, for those skilled in the art, according to the ideas of the present disclosure, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting 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; determining 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 sets 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 a 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 decoded angles of the rotary transformer; When the current change rate is greater than a preset threshold, calculating 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; 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 a preset threshold, the parameters of the permanent magnet traction motor are calculated according to the following formula: ； Where 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 electric 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.

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. The three-phase voltage includes the phase voltage of phase a, phase voltage of phase b, and phase voltage of phase c. 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, and Uc represent the phase voltage of phase a, phase b, and phase c respectively, Sa, Sb, and 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; and the current change rate of the permanent magnet traction motor is calculated based on the currents of the at least three groups of permanent magnet traction motors selected, including: calculating a first current difference between the excitation components of the currents 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 rate of change of the excitation components of the currents 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 of 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 component of the current of the at least two groups of permanent magnet traction motors.

5. The method according to claim 1, wherein 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 the rotational transformer decoding angles of each two adjacent groups in the at least three groups of the rotational transformer decoding angles is calculated, and the rotational speed difference is divided by the preset time interval to obtain the electrical rotational speeds of the at least two groups of the permanent magnet traction motors.

6. A parameter calculation device for a permanent magnet traction motor, characterized in that: The device comprises: An acquisition module 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; 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, based on the switching state of the inverter, 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 in a set of steady-state switching states at preset time intervals; a first calculation module, configured to calculate a 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; a second calculation module, configured to obtain the electric speed of the permanent magnet traction motor according to the selected at least three groups of decoded angles of the rotary transformer; a third calculation module, configured to calculate 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; 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: ； Where 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 electric 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. 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 according to any one of claims 1 to 5 is implemented.

8. 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 5.

9. 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 5 are implemented.

Images