Disturbance Rejection Control of Power Conversion System Based on Uncertainty and Disturbance Estimator

ABSTRACT The power conversion system (PCS) serves as the core device for power transfer between energy storage systems and the grid, effectively dispatching electricity generated by intermittent sources like renewable energy to match load demands. Conventional grid‐connected PCS architectures typically employ PI regulators for closed‐loop control of the power outer‐loop and current inner‐loop. However, this approach cannot effectively suppress disturbances caused by parameter command variations and grid condition changes. Consequently, traditional PCS systems exhibit degraded quality in grid‐connected output current during power command transients or sudden changes in grid voltage amplitude and frequency. To address these issues, this paper proposes a dual‐loop control method for PCS based on the Uncertainty and Disturbance Estimator (UDE). The dual‐loop parameters of the UDE control are systematically designed. Simulation and experimental results verify that the proposed control method significantly enhances the disturbance rejection capability of the PCS. The experimental results show that the response time of the PCS using the UDE controller can be reduced by more than 50% compared with that using the PI controller.