Method for calibrating key parameters of asynchronous motor of electric vehicle

Abstract

The invention discloses a method for calibrating key parameters of an asynchronous motor of an electric vehicle. The method comprises the steps: on a motor twin-trawling table, for different rotatingspeeds n and different torque instructions Te* under a current rotating speed, calibrating a d-axis given current value, a q-axis given current value and a rotor time constant value of the asynchronous motor of the electric vehicle by adopting a Proximal Policy Optimization (PPO) algorithm; storing a calibrated result in a motor controller in a form of a table so that the asynchronous motor of theelectric vehicle queries and uses the parameter can be inquired during actual operation. According to the method, the rotor time constant of the asynchronous motor of the electric vehicle is calibrated, and the d-axis given current and the q-axis given current of the motor are also calibrated; meanwhile, the calibrated parameters can enable the motor to have the maximum torque-current ratio characteristic under any rotating speed n and torque instruction Te*.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a method for acquiring key parameters of an asynchronous motor based on an electric vehicle. Background technique [0002] In the field of modern electric vehicle technology, power performance and cruising range are the key issues for the development of electric vehicles, and electric vehicle motors are the heart of electric vehicles. The performance of the motor directly affects the overall performance of electric vehicles. Generally speaking, during the operation of electric vehicles, it is hoped that the motor can accurately respond to the torque command issued by the vehicle controller, and the motor can always maintain the optimal torque-current ratio (that is, use the minimum current output Maximum torque), thereby improving the efficiency of the motor and extending the cruising range of the vehicle. [0003] In the field of motor control of electric vehicles, in ord...

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Problems solved by technology

In fact, only the calibration of the physical model parameters of the motor can only make the motor output the maximum torque at the current current, but this does not mean that the motor can output the torque command with the minimum current. For example, the patent "A method based on improved In "Asynchronous Motor Parameter Identification Method Based on Particle Swarm Optimization Algorithm (CN106953577B)", only the time constant of the rotor of the asynchronous motor is calibrated, and the d and q axis currents are not adjusted according to different speed and torque commands. Obviously, the asynchronous The motor is kept at the optimal current ratio state; as another example, in the patent "Asynchronous motor key information tracking method based on improved particle swarm algorithm (CN104362927A)", only the rotor time constant and excitation inductance are adjusted. Adjusting the d and q axis currents with the torque command cannot keep the asynchronous motor in the optimal current ratio state

Therefore, the traditional calibration method of electric vehicle asynchronous motor parameters can only make the motor run at a higher torque and higher efficiency state, but it cannot strictly guarantee that the motor can run at the optimal torque under any torque command. state of current ratio

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