A Novel Application of Modular Multi-Level Converters for Partially Shaded PV Systems

Abstract

This paper proposes a novel application of a modular multi-level converter (MMC) for photovoltaic (PV) generation system to maximize the efficiency in partial shading conditions. A DC/DC boost converter is placed between each sub-module (SM) of the MMC and the PV array to extract the maximum PV power. Furthermore, the proposed topology is enhanced with an independent active/reactive power control strategy for demand response purposes. The effect of circulating currents is also minimized using a proportional resonance (PR) controller. The proposed system is validated using time-domain simulations via MATLAB/Simscape power system toolbox on a 10 MW three-phase grid-connected MMC system.