Application of SVC and single-phase shunt capacitor to improve voltage profiles and reduce losses of unbalanced multiphase smart grid with PEV charging stations

In smart grids, the conventional approach of locating compensation devices based on the forecasted daily load curves is not realistic as the locations, times and durations of some loads such as plug-in electric vehicles (PEVs) and smart appliances are randomly changing during the 24 hour period. This paper proposes a new approach to improve the performance of unbalanced multiphase distribution systems consisting of single-, two- and three-phase networks with PEV charging stations. The approach is designated to perform online VRI ranking, place SVCs and single-phase capacitors at the weakest three-phase and single-phase buses, respectively; and then switch these devices in and out of the service according to the lowest voltage ranking index (VRI) values in order to improve voltage profiles and reduce total system losses. Simulation results are performed and compared for an unbalanced multiphase 13 node test feeder with PEV charging stations using DIgSILENT PowerFactory software.