Distributed Protection for Smart Substations Based on Multiple Overlapping Units

Taking advantage of the information sharing mechanism in smart substations,a distributed protection based on multiple overlapping units is introduced in this paper.The area division and the construction of protection units are studied based on the principle of differential protection.Mutual perception and information interaction among units,calculation with multisource information and coordinated protection schemes are proposed to improve the reliability and adaptability of the substation protection system.A multi agent system(MAS)approach is used to model the units’working process in various situations,such as communication failure and sampled data failure.Test results demonstrate that the method can accelerate the backup protection as well as reduce the power-off range.