ADRC Strategy-Based Control for Grid-Connected PV System using a Single-Phase Modular Multilevel Converter

Abstract

This paper deals with the control design of a single-phase Modular Multilevel Converter (MMC) interfaced with a photovoltaic (PV) system. The proposed strategy aims to simultaneously achieve two main objectives: i) power factor correction (PFC) on the grid side to improve power quality, and ii) regulation of the PV voltage to ensure precise maximum power point tracking (MPPT). To fulfill these objectives, a cascaded two-loop control structure is developed, in the outer loop, a filtered proportional-integral (FPI) controller is employed, while an Active Disturbance Rejection Control (ADRC) technique is adopted in the inner loop to enhance dynamic performance and disturbance rejection capability. In addition, a comparative analysis with conventional control approaches is carried out to highlight the effectiveness and robustness of the proposed method. The performance of the suggested controller is verified using MATLAB/Simulink simulation, and the obtained results demonstrate fast dynamic response, accurate tracking performance, and stable operation under different operating conditions.