Optimum Operation of Unbalanced AC Microgrid Using PEVs and DERs Scheduling With Time-Varying Loads

Abstract

The studies pertaining to scheduling of plug-in electric vehicles (PEVs) and distributed energy resources (DERs) in unbalanced AC microgrids (MGs) usually consider time varying lumped load models. This may lead to unrealistic values and inappropriate system support as unbalanced MGs have different loading levels for each phase. Therefore, in this paper optimal scheduling of DERs and PEVs is performed in 3-phase unbalanced AC MG whilst considering different per-phase loading levels of time-varying voltage dependent (TVVD) load models. At first, the impact of lumped loading and per phase loading approach on DERs scheduling in unbalanced AC MG is investigated for TVVD load models. Then, PEVs are connected in presence of DERs whilst considering per phase loading in case of all TVVD loads to minimise the generation cost and system losses. Enhanced grasshopper optimization algorithm (EGOA) is utilised to evaluate the optimum performance of unbalanced AC MG. The results demonstrate that the values obtained through a per-phase loading approach are more realistic and PEVs integration has a significant impact on cost reduction.