Optimal Operation of Droop-Controlled Islanded Microgrids

Abstract

Recently researchers have focused on the optimal operation of droop-controlled islanded microgrids (DCIMG). However, most of the papers consider only the economic objective. But, with increasing focus on environmental compliance, it has also become necessary to reduce emission from generation activities. Furthermore, most of the previous papers do not consider the heat demand in the microgrid and the uncertainties involved in load and renewable generation forecasting. This paper bridges all these gap areas by presenting a method for determining optimal droop settings of dispatchable distributed generation units in a DCIMG. The objectives are to minimize the operational cost and minimize the emission in the islanded droop-controlled microgrid while meeting all the operational constraints. The proposed formulation takes into account the electricity demand, the heat demand, load uncertainties, and renewable power uncertainties in the microgrid. Load and renewable power uncertainties are modeled by a stochastic scenario based approach. The multiobjective optimization problem is solved using fuzzified particle swarm optimization. The proposed method is validated on a 33-bus DCIMG test system. The results show the effectiveness of the proposed method.