Coordination Strategy for Digital Frequency Relays and Energy Storage in a Low-Inertia Microgrid

摘要

Abstract Recently, dynamic frequency stability problems have started to arise in microgrid systems with the increasing utilization of low inertia and intermittent renewable energy sources. This leads to limiting the maximum penetration of renewable sources in microgrids. In order to solve this problem and increase the penetration of renewable sources, the dynamic frequency controller of the microgrid should be enhanced. Therefore, this paper will provide virtual inertia response of superconducting magnetic energy storage coordinated with the load frequency control depending on a new optimal proportional-integral-derivative controller-based advanced swarm intelligence technique, named Moth Swarm Algorithm (MSA). Moreover, the proposed inertia control strategy is coordinated with digital frequency relay to enhance dynamic frequency stability and maintain microgrid dynamic security at high penetration levels of renewable sources and radical load change. To attest the superiority of the proposed technique, it has been examined using MATLAB/SIMULINK, considering different contingency cases and varying the inertia level of the studied microgrid. The results stated that the proposed coordination can effectively regulate microgrid frequency and maintain dynamic stability and security.