Research on Parameter Online Tuning Technology of Speed Controller of Permanent Magnet Synchronous Motor

For the problem of parameter self-tuning for speed controller in the vector control system of permanent magnet synchronous motor (PMSM), an online self-tuning method based on gradient search is proposed to tune the proportional and integral coefficients. The method uses the integral of the speed error square as a cost function. It calculates the gradient of cost function at each sample interval, and updates speed controller parameters according to gradient descent method. The proposed method does not need to identify the motor parameters at each iteration and it utilizes low computational resources. Because of short computation time and small memory space, the proposed method is easy to be implemented in practice. This paper simulates the performances of the speed controller implementing the proposed method under different conditions, and it compares the performances with traditional PID controller. The simulation results show that the proposed method adapts to the load change effectively and the system is stable.