Optimal Under-Frequency Load Shedding Scheme Based on PSO

Power system stability represents a significant challenge for security of system operation. When the load exceeds the generation, the system stability is affected. This can lead to cascading outages and shut-down of a major part of the power system that results in frequency decaying. Fast load shedding is the best way to avoid cascading outages and power system blackout. This paper proposes a novel scheme to control the optimal sheddable amount of the load at each stage for the under-frequency relay using Particle Swarm Optimization (PSO) technique. The proposed technique can be used to minimize the sheddable amount of loads at all stages. The proposed technique is applied to two different systems; IEEE 9-bus and IEEE 39-bus test system to verify its accuracy and effectiveness. The attained results prove the effectiveness of the proposed scheme to achieve the prescribed objectives. The comparison between the two systems is done.