基于改进直流母线电压滑模控制的三相交直变换器永磁同步发电机系统

A conventional proportional-integral (PI) controller is commonly used in the dc-link voltage control outer loop of permanent magnet synchronous generator (PMSG) systems; however, it cannot achieve consistent dc-link voltage control performance across the entire operating range, resulting in poor dynamic response. In contrast, dc-link voltage sliding mode control (SMC) offers faster dynamic performance compared to conventional PI control; nevertheless, stability analysis indicates that SMC may result in voltage tracking errors when the disturbance power is significant. In order to address this issue, a disturbance power observer based on recursive least squares (RLSs) with a forgetting factor is proposed. The RLS-based observer can achieve minimum variance estimation of the total disturbance power, and its convergence speed can be adjusted by tuning the forgetting factor. By feeding forward the RLS-observed power into the SMC (referred to as SMC + RLS method), the dc-link voltage control performance is significantly improved. Experimental results demonstrate that the proposed SMC + RLS method exhibits a faster dynamic response than both conventional PI control and state-of-the-art nonlinear controllers when the operating point changes. The disturbance power can, moreover, be quickly observed by the RLS-based observer, providing the SMC + RLS method with excellent anti-disturbance performance.