Power Quality Enhancement in Grid-Connected Photovoltaic Systems Integrated with Shunt Active Power Filter Using Modulated Model Predictive Control

This paper proposes a modulated model predictive control (M2PC) method based on current control for a grid- connected photovoltaic (PV) system integrated with shunt active power filter (SAPF). In conventional finite control set model predictive control (FCS-MPC), the optimal switching state is selected at each sampling instant, which leads to a variable switching frequency and causes current ripple and DC-link voltage fluctuations due to the limited number of switching states. To overcome this issue, the proposed method introduces a vector modulation stage to improve control performance. The method is applied to a grid-connected PV system integrated with SAPF that can both supply active power and compensate harmonic currents caused by nonlinear loads. Simulation results under varying solar irradiance show that the proposed method reduces harmonic distortion and improves the stability of the DC-link voltage compared to FCS-MPC.