Self-tuning Technique of PMSM Current Loop Based on Active Damping

Dual PI current controller based on dq shafting is the most widely used current control mode in PMSM servo system, but its parameter self-tuning technology is still a big challenge in the industry, especially considering the influence of digital delay such as calculation, sam-pling and updating. In this paper, a self-tuning scheme of current loop based on active damping is proposed. The ideal maximum gain of the controller without over-shoot is determined by root locus analysis, and active damping is adopted to provide two degrees of freedom control branches to improve the disturbance rejection characteristics of the system. Compared with the tradi-tional maximum gain tuning method, the proposed scheme provides the system with greater stability mar-gin and stronger disturbance resistance. The effective-ness of the proposed scheme is verified by experiments.