  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.
