Adaptive Nonlinear Active Disturbance Rejection Current Controller for Distributed Generation System Considering Uncertain Ripples

The onboard distributed generation system with high-speed permanent magnet synchronous generator (PMSG) faces significant current ripples issue due to the low stator inductance. The complex operating conditions of the electric vehicles lead to uncertain periodic and nonperiodic disturbances in the current loop, which deteriorates the control performance of current loop. To address this issue, this article proposes an adaptive nonlinear active disturbance rejection current controller for the distributed generation system of onboard high-speed PMSG. The improved adaptive nonlinear controller offers disturbance rejection capabilities for different forms of nonperiodic disturbances avoiding complex cascade structure. Additionally, an adaptive internal model controller is embedded within the current controller to suppress periodic disturbances. Compared with the traditional method, this method improves the tracking ability of high-frequency periodic signals and shows strong robustness against dc offsets. The proposed method reduces current distortion by approximately 8% and decreases the frequency identification convergence time by about 40%. The stability of the closed-loop system is analyzed, and the controller parameters are tuned. Finally, the feasibility and effectiveness of the proposed current control strategy are validated on a 60 kW gas turbine-driven PMSG generation platform.