Off-Line Parameter Identification of Asynchronous Motor Based on SOGI-PLL

Obtaining the initial values of asynchronous motor parameters is an important part in the speed sensorless vector control system of asynchronous motor. Aiming at the problems of low calculation efficiency and large memory occupation in calculating the amplitude and phase difference of current and voltage signals by discrete fast Fourier transform (FFT) in the off-line parameter identification method of asynchronous motor, this paper proposes to introduce the generalized second-order integrator phase-locked loop (SOGI-PLL) to lighten the asynchronous motor control system. Firstly, this paper introduces the basic principle of SOGI-PLL and the possibility of replacing FFT in off-line parameter identification of asynchronous motor. Then, based on Matlab/Simulink, it is verified that it is consistent with the traditional method in calculating the amplitude and phase difference of AC signal. Finally, the experiment is carried out on TMS320F280049PMS hardware platform. The results show that SOGI-PLL algorithm has the same calculation accuracy as FFT, and saves 88.31% memory space while optimizing the calculation process, which verifies the feasibility and superiority of this method for off-line parameter identification of asynchronous motor.