Fuzzy self-tuning PI control of PM synchronous motor drives

In this paper, a new gain self-tuning method for PI controllers based on fuzzy inference mechanism has been proposed and implemented. The essential idea is: 1). Define a dynamically changed reference trajectory in the error and error derivative plain, where we call it 'sliding trajectory'. 2). Compute the error area between the sliding trajectory and the effective one with a special algorithm, use this quantity as a performance index to evaluate the system response. 3) Draw a fuzzy relationship between a PI gain correction parameter and the performance index. 4) Based on the fuzzy inference mechanism, PI gains are calculated and tuned. The proposed method has been verified through simulations, using the speed control of a PM synchronous motor drive system as testbed. The obtained results demonstrate the effectiveness of this novel method.