Int J Performability Eng ›› 2023, Vol. 19 ›› Issue (1): 20-32.

### Effect on Transient Stability and Analyses Resulting from a Cyber-Attack on Frequency Relay Device

Darius Muyizerea,*, Lawrence K. Lettingb, and Bernard B. Munyazikwiyec

1. aAfrican Centre of Excellence in Energy and Sustainable Development, College of Science and Technology,University of Rwanda, KN 67 Street Nyarugenge, Kigali P.O. Box 3900, Rwanda;
bElectrical & Communications Engineering, Moi University, Eldoret 30100, Kenya;
cDepartment of Mechanical and Energy Engineering, College of Science and Technology, University of Rwanda,KN 67 Street Nyarugenge, Kigali P.O. Box 3900, Rwanda
• Contact: *E-mail address: Muyizere_218014544@stud.ur.ac.rw
• About author:Darius Muyizere is a PhD Candidate at the African Center of Excellence in Energy for Sustainable Development (ACE-ESD), University of Rwanda (UR) in electrical power system. His research interests include control systems, renewable energy, and power control improvements.
Lawrence K. Letting is a senior lecturer of the Electrical & Communications Engineering Department at the Moi University Kenya. His research interests include Microgrids & Smart Grids; Renewable Energy; State estimation in water distribution systems; optimization techniques.
Bernard B. Munyazikwiye received the B.Sc. degree in electromechanical engineering from the Kigali Institute of Science and Technology, Rwanda, in 2004, and the M.Sc. degree in mechanical engineering from the Jomo Kenyatta University of Agriculture and Technology, Kenya, in 2010. He received his Ph.D. degree in mechatronics with the University of Agder, Grimstad, Norway. He is a lecturer of Control Systems Engineering with the College of Science and Technology, University of Rwanda, Rwanda. His main research interests include modeling and simulation of dynamic systems, different models simulations (with a mathematical modeling approach), and control of electromechanical systems.

Abstract: Intelligent networks are the most common form of cyber-physical networks, which provide a strong connection between cyber communications and physical networks. As smart grid applications and technologies are developed and put into use, cyber security is becoming a serious problem. Therefore, it is crucial to research how cyber-attacks affect the frequency relay device of smart grids. This study investigates how cyber-attacks that increase latency in communications infrastructure affect system dependability. These were finished utilizing information gathered from a STATCOM or SVC that was linked to the grid. This paper presents two new approaches based on nonlinear controllers (NL) and PI controllers to minimize the negative impacts of cyber-attacks on the mentioned relay, as well as a novel detection and mitigation methodology for the FACTS based on the voltage threshold. There are case studies that examine the effects of fixed communication delays on transient angles and voltage stability just in electricity networks. Two methods of cyber-attacks were reviewed, and their impacts were demonstrated using the MATLAB Simulink-implemented Kigali national grid (KNG). According to simulation studies, certain communication delays resulting from cyber-attacks might lead the network to become unsustainable. Suggestions are made to improve electrical security in the event of cyber-attacks, damage, and delays in future power system grids against potential cyber-attacks.