CN-115333427-B - Permanent magnet synchronous motor three-phase short circuit transient modeling method and device

CN115333427BCN 115333427 BCN115333427 BCN 115333427BCN-115333427-B

Abstract

The invention discloses a permanent magnet synchronous motor three-phase short-circuit transient modeling method and device, wherein the method comprises the steps of obtaining a parameter value of a motor body, an initial value of the synchronous motor during short-circuit and constraint conditions; and establishing a three-phase short-circuit transient model based on the dq axis current value. According to the invention, a motor equation and an electromagnetic torque equation are established according to motor body parameters, and a transient analysis model of the active short circuit is deduced by determining initial conditions during short circuit, so that dq axis current and torque at any moment are obtained, an accurate data base is provided for realizing the active short circuit, and meanwhile, a controller can be helped to set reasonable compensation through the analysis model, so that accurate adjustment is realized.

Inventors

XU ZHONGBIN
BAO JIE

Assignees

中国第一汽车股份有限公司
中国第一汽车股份有限公司

Dates

Publication Date: 20260421
Application Date: 20220627
Priority Date: 20220627

Claims (4)

1. The three-phase short circuit transient modeling method for the permanent magnet synchronous motor is characterized by comprising the following steps of: Acquiring a parameter value of the motor body, an initial value and a constraint condition when the motor is in short circuit, wherein the parameter value of the motor body comprises a resistor, a direct-axis inductor, a quadrature-axis inductor, a permanent magnet flux linkage and a pole pair number, and the initial value comprises an initial torque, an initial rotating speed, an initial current amplitude and an initial current dq axis component; Determining a dq-axis current value of the permanent magnet synchronous motor based on the parameter value, the initial value and a constraint condition; Determining a dq-axis current value based on the motor body parameter and an initial value at the time of the short circuit includes determining an electromagnetic torque based on the motor body parameter; Establishing a three-phase short-circuit transient model of the permanent magnet synchronous motor based on the dq axis current value to obtain dq axis current and torque; establishing a three-phase short-circuit transient model based on the dq-axis current value includes obtaining a dq-axis current sub-model based on the dq-axis current value; The dq axis current sub-model comprises a first current sub-model, a second current sub-model and a third current sub-model, wherein the first current sub-model is a change value of dq axis current along with time when the initial value of the current is zero; Obtaining the dq-axis current sub-model based on the dq-axis current value includes determining a first current sub-model based on the dq-axis current value when the current initial value is zero, and determining a second current sub-model based on the dq-axis current value when the current initial value is non-zero.
2. A permanent magnet synchronous motor three-phase short circuit transient modeling device, characterized by comprising: The acquisition module is used for acquiring parameter values of the motor body, initial values and constraint conditions when the motor is in short circuit, wherein the parameter values of the motor body comprise resistors, direct-axis inductors, quadrature-axis inductors, permanent magnet flux linkages and pole pairs, and the initial values comprise initial torque, initial rotating speed, initial current amplitude and initial current dq axis components; a determining module, configured to determine a dq-axis current value of the permanent magnet synchronous motor based on the parameter value, the initial value, and a constraint condition; The determining module is also used for determining electromagnetic torque based on the motor body parameter, and determining the dq axis current value based on the electromagnetic torque and the current initial value; The model building module is used for building a three-phase short-circuit transient model based on the dq axis current value to obtain dq axis current and torque; the model building module is further used for obtaining a dq-axis current sub-model based on the dq-axis current value; The dq axis current sub-model comprises a first current sub-model, a second current sub-model and a third current sub-model, wherein the first current sub-model is a change value of dq axis current along with time when the initial value of the current is zero; The model building module is further used for determining a first current sub-model based on the dq-axis current value when the current initial value is zero, and determining a second current sub-model based on the dq-axis current value when the current initial value is not zero.
3. A storage medium storing a computer program, which when executed by a processor performs the steps of the method of claim 1.
4. An electronic device comprising at least a memory, a processor, the memory having stored thereon a computer program, characterized in that the processor, when executing the computer program on the memory, realizes the steps of the method as claimed in claim 1.

Description

Permanent magnet synchronous motor three-phase short circuit transient modeling method and device Technical Field The disclosure relates to the technical field of permanent magnet synchronous motor model construction, in particular to a permanent magnet synchronous motor three-phase short-circuit transient modeling method and device. Background Currently, environmental and energy sources are becoming an increasing concern. In the field of automobiles, high-efficiency, energy-saving and environment-friendly new energy automobiles become one of the necessary development trends of the automobile industry. The permanent magnet synchronous motor driving system can achieve the purposes of low energy consumption and zero emission, and has great market prospect. In the control of permanent magnet synchronous motors, in particular for vehicles, often unpredictable faults and harsh conditions are encountered. When the fault level reaches a certain degree (overcurrent, overvoltage, stall, etc.), a method is necessary to quickly discharge the energy so as to achieve the effect of quick stopping. At present, two modes of realizing active short circuit are generally adopted, one mode is realized by a hardware design mode, an active short circuit is designed, the working state of a motor is monitored by a software design mode, whether the motor needs to enter a safe state or not is judged, when the motor needs to enter the safe state, back electromotive force line voltages at two moments are calculated according to the rotor positions of a motor controller at the current moment and the next moment, an enabling signal of the motor controller is generated based on the motor entering the safe state and a motor threshold value, the dq axis current of the motor is controlled to be a characteristic current, and a control action signal is output, so that a driving signal can safely control an inverter to conduct a corresponding switch. However, by detecting the current, the voltage and the motor rotation speed, comparing with the set threshold, after the threshold is reached, the three-phase bridge inverter is controlled to enter a short circuit mode, mathematical analysis and description are not performed on the transient process of active short circuit, dq axis current and torque at any moment cannot be obtained, and the motor current and torque are easy to be out of control. Disclosure of Invention In view of the above, the present disclosure aims to provide a method and a device for modeling a three-phase short-circuit transient state of a permanent magnet synchronous motor, so as to solve the technical problem that current and torque of a dq axis at any moment cannot be predicted in the prior art, and current and torque are easy to be out of control. In order to achieve the aim, in a first aspect, the disclosure provides a three-phase short-circuit transient modeling method of a permanent magnet synchronous motor, which comprises the steps of obtaining a parameter value of a motor body, an initial value and a constraint condition when the motor is in short circuit, determining a dq axis current value of the permanent magnet synchronous motor based on the parameter value, the initial value and the constraint condition, and building a three-phase short-circuit transient model based on the dq axis current value to obtain dq axis current and torque. In some embodiments, the motor body parameters include resistance, direct axis inductance, quadrature axis inductance, permanent magnet flux linkage, pole pair number. In some embodiments, the initial values include a starting torque, a starting rotational speed, a starting current amplitude, a starting current dq axis component. In some embodiments, the determining the dq-axis current value based on the motor body parameter and the initial value at the time of the short circuit includes determining an electromagnetic torque based on the motor body parameter, and determining the dq-axis current value based on the electromagnetic torque and the initial value of the current. In some embodiments, the establishing a three-phase short-circuit transient model based on the dq-axis current value includes obtaining a dq-axis current sub-model based on the dq-axis current value, and determining a braking torque sub-model based on the dq-axis current model. In some embodiments, the dq-axis current sub-model comprises a first current sub-model, wherein the first current sub-model is a time-dependent value of the dq-axis current when the initial value of the current is 0, and a second current sub-model, wherein the second current sub-model is a time-dependent value of the dq-axis current when the initial value of the current is other than 0. In some embodiments, the obtaining the dq-axis current sub-model based on the dq-axis current value includes determining a first current sub-model based on the dq-axis current value when a current initial value is 0, and determining a second current sub-mode