Single-Current Feedback Active Damping Control for High-Speed PMSM With LLCL Filter

As it is well recognized, LLCL filter effectively reduces the total inductance of the sinewave filter. In this paper, a unified single-current feedback active damping method is proposed for LLCL-equipped high-speed permanent magnet synchronous motor. With the unified discrete model, this method can be utilized in both inverter current feedback-only and motor current feedback-only systems. The coefficient selection and simple digital implementation methods are developed to design the damping system efficiently. The proposed method performs well even with mismatched parameters, such as a $\pm$ 15% error in filter parameters and a $\pm$ 40% error in motor inductance. Additionally, the study confirms the advantages of LLCL filter over LCL filter in terms of total inductance in high-speed motor drives. Finally, the effectiveness of the proposed method is validated by experimental results of a 12kr/min(1000 Hz) HSPMSM.