Modified Inverter Control of Distributed Generation for Enhanced Relaying Coordination in Distribution Networks

This paper presents a modified power control to integrate inverter-based distributed generation (DG) in distribution networks. This control is designed for mitigating the maloperation of the overcurrent protection coordination, due to the DG current contribution during the fault. The proposed power control introduces a new approach to perform the inverter control by using new orthogonal components of the grid voltages that provide a modified controlled power. Using the proposed methodology, the injected current to the grid during faults is limited to the DG-rated level. By controlling the reference power based on a proposed function of the per-unit terminal voltage, the injected current is limited to a desired value. The results of the simulated system corroborate the control capability to completely limit the inverter-based DG effects on protection coordination in the distribution level.