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

  • Sayed M. Said Aswan University, Aswan, Egypt
  • Emad A. Mohamed Aswan University, Aswan, Egypt
  • Bálint Hartmann Budapest University of Technology and Economics, Budapest, Hungary.
  • Yasunori Mitani Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka 804-8550, Japan.


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.

Author Biographies

Sayed M. Said, Aswan University, Aswan, Egypt
Department of Electrical Engineering, Faculty of Engineering, &Ph.D. at Department of Electric Power Engineering, Budapest University of Technology and Economics, Budapest, Hungary.
Emad A. Mohamed, Aswan University, Aswan, Egypt
Department of Electrical Engineering, Faculty of Engineering
Bálint Hartmann, Budapest University of Technology and Economics, Budapest, Hungary.
Department of Electric Power Engineering.
Yasunori Mitani, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka 804-8550, Japan.
Department of Electrical and Electronic Engineering.


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How to Cite
SAID, Sayed M. et al. Coordination Strategy for Digital  Frequency Relays and Energy Storage in a Low-Inertia Microgrid. Journal of Power Technologies, [S.l.], v. 99, n. 4, p. 254–263, jan. 2020. ISSN 2083-4195. Available at: <>. Date accessed: 29 july 2021.
Energy Conversion and Storage


digital protection; load frequency control; low-inertia microgrid; superconducting magnetic energy storage

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