SUMMARYThis paper proposes an improved binary multi-objectives particle swarm optimization (IB-MOPSO) for solving optimal multiple protective devices placement using improved reliability model in a microgrid (MG) system. The multi-objectives are to minimize system average interruption frequency index, system average interruption duration index, and total cost including investment and interruption cost. Binary multi-objectives PSO (B-MOPSO) is enhanced by using a bell shape function and three particle movement strategies including global guidance located in the least crowded areas, perturbation with different evolution method, and coverage of unexplored search space in the non-dominated front. For MG planning, IB-MOPSO can find better locations and number of protective devices including reclosers, switches, and fuses than B-MOPSO and ant colony optimization on the 51 section Provincial Electricity Authority of Thailand MG distribution system.