Optimization of Permanent Magnet Synchronous Motor Speed and Rotor Position Detection Based on High Frequency Pulsation Voltage Injection Method

Permanent magnet synchronous motor is an important power device in industrial system. To enhance its performance at idle speed, this paper designs a new rotor observer using the conventional voltage signal injection method as a reference. A generalized second-order integrator with center frequency adaptively varying according to the speed is used to extract the response signal of currents, and a square-wave signal with the same frequency as the injected signal and the extracted signal are multiplied instead of a low-pass filter. The simulation model was then built and tested, and after continuous testing it was found that using the new rotor observer designed reduces the speed convergence time by 0.79 s when the motor is started at no load and by 0.6 s when running a sudden load increase at constant speed. It reduces the position error by 0.29 rad when running a speed switch at no load and reduces the position error by 0.11 rad and the speed error by 0.24 r/min when running a sudden load increase at constant speed. The observer designed in this paper can reduce the speed convergence time and rotor position error, has better dynamic performance, and has certain application value.