Cyber–physical energy system toward safety in smart grids

Abstract

The power system operation, stability, and reliability are strongly dependent on the network protection system performance. On the other hand, the penetration of the renewable energy power plants into power grids drastically affects power networks and smart grids’ stability and reliability because of their fast dynamics in comparison to conventional power generators. Hence, power networks are considered as a complex cyber–physical energy system with vast interactions and communications among consumers and generators. In this condition, a reliable monitoring and control system can augment the safety, security, and operation of such an intricate system. Suitable time coordination between the operations of power grids protection relays is one of the most challenging issues to protect the power system properly. In this paper, a reliable supervisor system (RSS) with fast and precise control ability is proposed to improve power systems and smart grids protection system operations. The device utilizes a safe robust communication way which provides a condition for the available relays on two sides of a line to share their data. For this reason, the proposed device is able to diagnose the fault on a short transmission line quickly upon the event occurrence. In other words, fast communication between two sides of a short transmission line helps the protection system to work faster in the presence of a fault. In addition, quick handshaking and data sharing of the network different points provided by the RSS enable grid circuit breakers to disconnect a fault from the system as fast as possible. The proposed system, then, can easily find a defect location and disconnect a faulty line from the grid. According to the experimental results provided in this paper, the RSS can effectively corroborate the network stability.