Permanent magnet synchronous motor rotor temperature estimation method and device, motor and vehicle

The invention relates to a permanent magnet synchronous motor rotor temperature estimation method and device, a motor and a vehicle, and the method comprises the steps: building a flux linkage observer of a continuous model based on a voltage equation in a d-q coordinate system, introducing a difference between an estimated current and an actual current as feedback, and building a corresponding relation between a rotor temperature and a flux linkage; and estimating the real-time rotor temperature according to the value of the flux observer, and carrying out temperature post-processing according to the working condition of the motor. The rotating speed or the current is used as a condition for enabling the observer, when the rotating speed or the current is smaller than a threshold value, the output temperature is kept unchanged, and the temperature keeping condition is used as a reset condition from meeting to not meeting. When the temperature maintaining condition is not met, the temperature is obtained and