LAUSR

This paper addresses reliability evaluation of microgrid with distributed generation and directional protection considering protection failure. A second-order Markov-based method that considers up to two simultaneous faults and a first order approximate method have been proposed. AC Optimal Load Shedding (AC-OLS) is adopted in each state considering network constraints in all resulted islands. Simulation results are given to assess the effect of protection failure probability on reliability indices. The effects of tie-lines, loop operation, switching time, energy storage and network constraints are investigated. The proposed method can be used for studying feasibility of investment on protection upgrade and preventive maintenance to reduce protection failure probability. The proposed algorithms can also be utilized for evaluating effect of protection schemes and coordination on reliability.