Scheduled charging of electric vehicles and the increase of hosting capacity by a stationary energy storage

Abstract

The advancing electrification of the transportation andheating sector is expected to cause several operationalchallenges for distribution system operators (DSO),mainly in the form of thermal overloading of assets andvoltage limit violations. Especially, low voltage (LV)networks are prone to failure.In order to integrate electric vehicles (EVs) into LVnetworks, two charge scheduling algorithms for EVs arepresented. The scheduling algorithms, namely “Basic-Scheduling” and “Time-Of-Use (TOU)-Schedulingdistribute the power demand of EVs pro-actively to preventdetrimental effects on power grids.A simulated case study of a residential area including 20dwellings has shown that both, “Basic-Scheduling” and“TOU-Scheduling” can effectively mitigate assetoverloading. Different examinations regarding theenvironmental conditions have been carried out.Another objective pursued was the examination on how astationary battery energy storage system (BESS) canincrease the hosting capacity of a network. Commerciallyavailable Vanadium-Redox-Flow batteries (VRFB) arevirtually integrated in the network of the residential area.A 30 kW/100 kWh VRFB was able to relieve transformeroverloading in three out of four cases for uncontrolled EVcharging. Only in a modified scenario, transformeroverloading occurred. A 50 kW/200 kWh VRFB mitigatedtransformer overloading in every scenario considered.