A motor protection method for automobile based on rotor magnet steel temperature

Abstract

A motor protection method for an automobile based on rotor magnetic steel temperature includes adopting a rotor magnetic steel temperature on-line estimation system to realize rotor magnetic steel temperature monitoring, and protecting the automobile motor according to current rotor magnetic steel temperature. The rotor magnetic steel temperature online estimation system comprises a flux observer,a temperature estimation module and a motor protection module. The input signal of the flux linkage observer is stator voltage and current, the output signal is rotor magnetic steel flux linkage signal, the rotor magnetic steel flux linkage signal is calculated according to the stator voltage and current, and the rotor magnetic steel flux linkage signal is output to the temperature estimation module; the temperature estimation module receives the output signal of the flux linkage observer, calculates the rotor magnetic steel temperature, and transmits the calculated rotor magnetic steel temperature to the motor protection module; and the motor protection module receives the rotor magnet steel temperature and takes protective measures for the automobile motor according to the rotor magnetsteel temperature.

Description

technical field [0001] The invention relates to the field of motors, in particular to a method for protecting a vehicle motor based on the temperature of a rotor magnetic steel. Background technique [0002] Due to its high energy density and easy control, permanent magnet synchronous motors have been widely used in current industrial production and transportation. Especially in the new energy vehicle industry, the market share of permanent magnet synchronous motors has always been high. During the operation of the permanent magnet synchronous motor, the temperature of the stator and the motor controller need to be monitored in real time to prevent the risk of overheating of the motor or the controller. Due to its own structure and characteristics, the rotor magnet is prone to demagnetization when the temperature is too high, and this change is irreversible. Once the rotor magnet demagnetizes, it will greatly affect the performance of the motor, making the car uncontrollabl...

AI Technical Summary

Problems solved by technology

Due to its own structure and characteristics, the rotor magnet is prone to demagnetization when the temperature is too high, and this change is irreversible. Once the rotor magnet demagnetizes, it will greatly affect the performance of the motor, making the car uncontrollable during operation. risks of

[0003] (1) However, since the rotor is always in a state of high-speed rotation, it is very difficult to install a temperature sensor on it

[0004] (2) The traditional method is to use the current value of the motor and the corresponding value of the rotor magnet flux linkage and the motor under no-load conditions to perform vector calculations on the corresponding rotor magnet flux linkages at different speeds to obtain the current rotor magnet flux of the motor. However, this method still needs to install a slip ring sensor inside the motor in the experimental stage to ensure the accuracy of the experiment. The experimental work is more complicated and the experimental cost is expensive.

[0005] (3) The traditional motor temperature protection strategy often only considers the temperature of the motor stator. Due to the low requirements on the safety performance of the applied system, the motor rotor magnet temperature safety protection strategy is often not implemented. When the motor is running at high temperature and high torque, it is easy to Demagnetization of the rotor magnet of the motor

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