Fault Current Limiter Controller for the Protection of Inverter Based Distributed Generation

Abstract

Power systems are becoming more vulnerable to different faults due to high current. This threat is increasing day by day due to the shift of power system from conventional generation to power electronic-based distributed generation. Such inverter-based distributed generation (IBDG) system is adopted to integrate different renewable energy sources especially solar photovoltaic (PV) to the grid. In this work bridge type fault current limiter (BFCL) has been suggested as a solution to the fault problem in IBDG system. The BFCL is connected to the AC side of the IBDG system and a proper controller is designed and implemented to control the reactance of BFCL. The voltage at the point of common coupling (PCC) is used as input of the BFCL activation controller. Outer controller loop is proposed for controlling the DC link voltage of IBDG, where an inner current controller is designed for controlling the power exchange between AC and DC sides of the IBDG. Both the balanced and unbalanced faults are applied in the AC side of the IBDG system to demonstrate the effectiveness of the suggested controller. A great improvement in the system performance is observed with the proposed fault current limiter based control strategy. The proposed strategy is also compared with the traditional control strategy and it is observed that the proposed one outperforms the classical one.