On-line parameter identification and self-commissioning of current controller for servo motor drives considering time delay in both modeling and control

The main theme of this paper is to propose an online parameter identification and self-commissioning of current controller for servo motor drives as time delay is taken into consideration. The advantages of considering time delay include increase of current controller bandwidth and easy to achieve delay compensation. The electrical parameters and time delay required for self-commissioning of current controller are identified on-line through injecting signal and real-time Fast Fourier Transform (FFT) under standstill. The current controller gains are determined based upon the magnitude optimal method as the delay is considered while retaining the maximum phase margin. The experimental results will be shown, which are derived from DSP-controlled PMSM servo drives. With the proposed parameter identification method, in which time delay identification is included, the measured bandwidth of current loop is improved as compared with that without such consideration. These results confirm the effectiveness and claims of the proposed method.