Active Fault Tolerant Control of Grid-Connected DER: Diagnosis and Reconfiguration

In this paper, an actuator active fault-tolerant controller (FTC) is proposed for the voltage source converter (VSC) which interfaces a distributed energy resource (DER) to the power grid. The proposed active FTC includes two units: diagnostic and reconfiguration. By testing the consistency of the known input signal and measured output current with the faultless model of the system, the actuator fault is identified by diagnostic unit. Using virtual actuator (VA) in the case of actuator failure, the reconfiguration unit adopts the controller to the faulty VSC model so that the active and reactive output powers of VSC track the reference values desired by the power grid. The performance of the proposed FTC is shown by the numerical simulation of a grid-connected VSC.