Discrete-Time Dynamic-Decoupled Current Control for LCL-Equipped High-Speed Permanent Magnet Synchronous Machines

This article proposes a discrete-time dynamic-decoupled current controller for an <italic>LCL</italic>-equipped high-speed permanent magnet synchronous machine with only the motor currents measured. The controller is designed in the synchronous coordinate based on a complex <inline-formula><tex-math notation="LaTeX">$\boldsymbol{z}$</tex-math></inline-formula>-domain transfer function. The main contribution of the proposed current controller is the robust dynamic decoupling performance to achieve better transient behavior. Moreover, an effective coefficient selection method is developed to acquire sufficient phase margin and gain margin, even with the system parameters varying <inline-formula><tex-math notation="LaTeX">$\boldsymbol{\pm 50\%}$</tex-math></inline-formula>. Additionally, the stable region of the <italic>LCL</italic> resonance with the proposed method is discussed. Finally, the effectiveness of the proposed method is verified by driving the tested motor to 100 kr/min.