Analysis and design of a decoupling current controller for AC machines: a unified transfer-matrix approach

This paper makes an analysis on decoupling current controllers designed in the synchronous reference frame using a transfer matrix for salient/non-salient AC machines, and proposes a novel anti-windup method under voltage constraint based on geometrically realizable reference modification. The analysis describes mathematical conditions by model-matching technique for d-and q-axes current controllers to be decoupled with one-degree-of-freedom and extended to two-degree-of-freedom. The relationship with the conventional proportional-integral type is also discussed. This work takes example by a permanent-magnet synchronous machine. The simulation and experimental results show the feasibility and performance of the proposed anti-windup technique.