Scheduled Charging and Discharging of Electric Vehicles for Charging Cost Optimization

Naveen .; Dr. Puneet Pahuja

Abstract

The growing number of Electric Vehicles (EVs) will have remarkable impacts on the power grid as it leads to the increase in total energy consumption. This increases the overall burden on the grid which would require new power plants. However, it is possible to minimize the impact by proper scheduling for charging and discharging of electric vehicles. In this paper, three optimal schemes have been compared i.e. global optimal scheduling scheme and local optimal scheduling scheme and equal allocation scheme for EV charging and discharging. The first objective is to flatten the load profile. The EVs can be charged during off peak hours when the demand is less and can be discharged during peak hours when the demand is high. It will result in the constant power demand from the grid. The second objective is to minimize the total charging cost through scheduled charging and discharging.The globally optimal scheduling scheme provides the globally minimal total cost but this scheme is impractical as it require information about future base loads and arrival time of each EV and charging periods of EV’s that will arrive in future. While local optimal scheduling scheme is quite practical as it considers only current ongoing EV sets. This scheme is scalable and resilient to dynamic EV arrival. In equal allocation scheme; the charging power of an EV is allocated based on the electricity price on the previous day in an interval. Secondly, the charging power is equal in each interval. The total cost for each scheme is calculated. Moreover, through the software tool, we demonstrate that the locally optimal scheduling scheme can achieve a close performance compared to the globally optimal scheduling scheme.

Abstract

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