Tuning method for PI controllers of PMSM driving system

Based on the model of permanent magnet synchronous motor(PMSM) speed regulating systems in frequency domain, closed form expressions for current and speed PI controller parameters are derived. Combined with practical engineering, the design procedure has considered the influences of inverter, dead time, time delay, feedback filters and other non-ideal factors and clearly defined the reasonable range of open-loop cut-off frequencies and phase margins for the current loop and the speed loop. According to the system performance requirements, the proposed method achieves PI controller parameters by setting the desired cut-off frequencies and phase margins of the current loop and the speed loop. It can also inverse-calculate the cut-off frequencies and phase margins to evaluate the performance of the given K_p and K_i parameters. This approach establishes the relationship among the system frequency domain parameters, controller parameters and system performance in time domain, which has made the tuning target intuitive and clear. With clear physical meaning of the parameters and practical tuning procedure, the proposed strategy could be useful for a first and robust tuning of electric drives control architecture. A large number of simulations, as well as experimental results verify the correctness and validity of the proposed method.