Optimal coordination of overcurrent relay for offshore wind farm integrated to onshore grid with VSC-HVDC

Overcurrent (OC) relay is one of the most commonly used protective relays in the power system. Coordination of overcurrent relays is a challenging task in the field of offshore wind farm (OWF). A reliable protection system is needed for transmitting large amount of power over long distances. An optimal relay coordination using overcurrent relay is used at four different points in the OWF. The optimal coordination of OC relay is carried out by the exploration of different meta heuristic algorithm such as Genetic algorithm (GA), Particle swarm optimization (PSO) and Gravitational search algorithm (GSA) algorithm. The formulation of objective function is accomplished by two variables such as time multiplier setting (TMS) and plug setting multiplier (PSM). Thus this multiobjective optimization is explored to minimize the operating time of the associated relay that exists in the ac side of OWF.