A Decentralized Adaptive Voltage Regulation Control Strategy Based on A Novel Modular Three-Phase Integrated PV Inverter

Abstract

In recent years, cascaded H-bridges have attracted interest for applications in photovoltaic. As applications evolve to higher voltage levels, the number of cascaded sub-modules will be large, which needs complex communication and brings great challenge to the control system. In order to solve the power mismatch problem, the existing control method will also greatly increase the complexity of the control system. This paper proposes a decentralized control strategy based on a modular three-phase integrated PV inverter. The characteristic of the modular topology makes the interphase power mismatch completely avoided. And the MPPT operating range of cascaded system under the severe inter-bridge power mismatch is greatly extended by using the proposed decentralized adaptive voltage regulation control strategy that dynamically adjusting the DC-link voltage of the sub-module’s H-bridge. The feasibility of the proposed strategy is verified by simulation.