Research of Permanent Magnet Synchronous Motor Sensorless Control Based on Fractional Order PLL

For those surface mounted permanent magnet synchronous motors (PMSM), a fractional order phase lock loop (FO-PLL) sensorless control method is proposed. On the basis of PMSM model in stationary coordinate, a rotor flux linkage observer is constructed. By designing the modified integrator and introducing the high pass filter, output saturation distortion or numeric overflow caused by integrator zero drift are solved. The observing results have no DC component. Moreover, a fractional order PLL is designed to estimate the PMSM rotor angle and speed. Parameters of FO-PLL controller are tuned and optimized via ITAE criterion. System indiscrimination degree is improved effectively. By using Oustaloup recursive filter, high order integer order approximation to fractional order integrator is realized. Last, the effectiveness and engineering application of the proposed method are verified on a MATLAB based PMSM control simulation platform.