Current Control Scheme for LC-Equipped PMSM Drive Considering Decoupling and Resonance Suppression in Synchronous Complex-Vector Frame

Abstract

Permanent-magnet synchronous machine drive with sine wave filter has features of low insulation stress and current harmonics. However, the filter can affect the current control of machine. Specifically, the increased axes cross-coupling degrades the response performance in the transient state, and the introduced resonant frequency oscillations can make the system unstable. To solve the issues, a complex-vector frequency-domain model of LC -equipped permanent-magnet synchronous machine drive is established in this article. Moreover, a quantitative index related to the symmetrical extent of double-sided frequency responses is introduced to evaluate the performance. A decoupling strategy based on the modified complex-vector controller is proposed and compared against conventional methods in terms of decoupling performance and parameter robustness based on the aforementioned evaluation index. Furthermore, an active damping method based on virtual impedance in parallel with the stator inductance is proposed to suppress the resonance. The quantified double-sided frequency-domain analysis is performed to illustrate the relationship between cross-coupling and system stability. Then, the systematic codesign procedure of decoupling controller and active damping link in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$z$ </tex-math></inline-formula> -domain is proposed. Finally, the experimental results show that the proposed scheme can improve the overall control performance in both transient and steady states.