PMSM speed and position estimation method based on parameter adaptive EKF

The invention relates to a PMSM (permanent magnet synchronous motor) speed and position estimation method based on a parameter self-adaptive EKF (extended Kalman filter), which realizes double-closed-loop control of a current loop and a speed loop of a motor according to an SVPWM (space vector pulse width modulation) theory and a method for controlling a motor vector. Ualpha, ubeta and ialpha and ibeta under an alpha-beta static coordinate system are obtained through FOC control and serve as input of an extended Kalman filtering algorithm, meanwhile, phase resistance, phase inductance and flux linkage of the motor need to serve as input parameters, and the rotor rotating speed we and the rotor position theta are obtained through extended Kalman recursion. Compared with traditional extended Kalman filtering, an accurate process noise variance Q must exist when a priori estimation covariance is obtained, the improved method provided by the invention is used for obtaining the priori estimation covariance based o