Phase locked loop-based permanent magnet synchronous motor rotor position and speed observation method

The invention provides a phase locked loop-based permanent magnet synchronous motor rotor position and speed observation method. Firstly, an alpha axis component and a beta axis component of a motor rotor magnetic pole flux linkage which are well observed in advance are read; then, motor angle estimation error and output of a phase locked loop controller at the kth sampling time are calculated; and finally, output of a phase locked loop integrator is obtained, that is, a motor rotor position estimation value at the kth sampling time. The calculated motor rotor position and speed estimation value can replace an actual motor rotor position and speed estimation value, the method can be used for motor vector control, position sensorless control on the motor can be realized, and a position and speed sensor can be saved.