Fault Tolerant Control Method for Three-Level Photovoltaic Inverter Based on Redundant Voltage Space Vector

摘要

Power devices short circuit or open circuit fault can have serious impact on the reliability of the photovoltaic inverter system during the operational process. On the basis of analysis of the fault characteristics and types with neutral point clamped three-level photovoltaic inverter as the research object, fault diagnosis logic is given. Fault tolerant control strategy for three-level photovoltaic inverter based on redundant space vectors is proposed. The changes of photovoltaic inverter space vector are analyzed before and after the fault occurs, photovoltaic inverter will maintain fault-tolerant operation by utilizing the redundant voltage space vectors. Simulation and experiment verify the feasibility and effectiveness of the proposed fault tolerant control method and the proposed method has a good fault tolerant performance.