Comparison of Charging Strategies of Electric Vehicles Using Local Power Production to Minimize Carbon Emissions

摘要

The German WINNER research project aims at controlling and optimizing local power production, distribution, and consumption in residential areas. Beside residents, who consume electrical energy uncontrollable, there are electric vehicles of a car sharing provider as well. Their charging process can be monitored and controlled. Furthermore, we have a mid-size photovoltaic (PV) power plant on the roof of the residential building. Within this local area, we measure energy consumptions and productions. This paper covers subsequent investigations on the possibility of using different charging strategies of electric vehicles from the view of the grid side. Thus, we have to measure energy consumption and production, calculate the surplus and store this excessive energy in the vehicle accumulator. We aim to be neutral against the local energy grid or at least not unhelpful, i. e., we have to avoid power withdrawal if possible. In this paper, we abstract from real use case with electric vehicles. We are using a simple battery model and make some assumptions on the energy consumption and PV production referring to our measurements. Afterwards, a recurrent approach is used to schedule charging and discharging processes along the day. We consider various charging aims over time, i. e., we vary the charging states and times, at which the aimed battery charging state should be reached. Finally, we use our system to answer the question, if our approach to lower the grid load was worth it. For low PV power days and cloudy days, we found usable strategies. Referring to PV peak days we had to do more intensive investigations.