Design of a Decentralized Wide-Area Damping Controller Resilient to Permanent Communication Failures

Wide-Area Damping Controllers (WADCs) are controllers that use remote data from Phasor Measurement Systems (PMUs) to mitigate low frequency oscillation modes of power systems with low damping ratios and are mainly effective in inter-area modes. However, communication failures or cyber attacks on the WADC channels can compromise its operation and even cause instability in the closed-loop control system. The greater the number of communication channels, the greater the susceptibility to failures. Thus, centralized control structures with multiple inputs and multiple outputs present the vulnerability of greater communication channels susceptible to failures. This work presents a method of designing a decentralized WADC to improve the damping rates of the closed-loop control system and that is robust to a permanent communication failure of the WADC channels. A decentralized WADC would have fewer connection pairs and thus be less likely to cause system problems due to a communication failure. The design method is based on an optimization model and the Particle Swarm Optimization, Crow Search Algorithm and Greylag Goose Optimization algorithms are applied and compared. Case studies were performed on the IEEE 68-bus system using modal analysis and dynamic simulation with contingencies.