A Modular Inverter for Multi‐Distributed Energy Integration With Modulation Strategy Optimization and Fault Protection

ABSTRACT Different types of distributed energy resources (DERs) exhibit distinct resource endowments and prominent intermittency and volatility. Unordered grid connection will threaten the stability of the power grid. To address this issue, this paper proposes a topology combining the quadruple active bridge (QAB) converter, cascaded H‐bridge (CHB) inverter, and AC voltage balancer (ACVB) to enable the integration and grid connection of multiple DERs. Taking the integrated grid connection of photovoltaic and energy storage as an example, all feasible operating modes of the modular inverter are identified, and the design ideas for the corresponding control strategies under each mode are presented. Meanwhile, aiming at the shortcomings of a complex modulation strategy and the lack of a submodule fault protection mechanism for the ACVB in this architecture, an improved modulation strategy for the ACVB is proposed to reduce system control complexity, and a submodule fault‐tolerant switching strategy is designed to ensure stable system operation under submodule faults. Finally, a laboratory prototype is built, and the feasibility of the proposed modular inverter, as well as its improved modulation strategy and fault protection strategy, is verified through experiments.