Dynamic TOU Tariff for the Hierarchical Coordination of PEV Charging

Abstract

This paper presents a three-stage methodology for the charging coordination of Plug-in Electric Vehicles (PEVs), incorporating the calculation of Time-of-Use (TOU) daily rates to mitigate the increase of energy cost of the aggregators caused by the coordination. Our previous work has been taken as a basis, where a PEV coordination methodology is proposed to minimize the Loss of Life (LOL) of Primary Distribution Transformers (PDTs) in the network supplying the charging of a set of PEVs. In the first stage, the charging power profiles of PEV aggregators, which are favorable for the Distribution System Operator (DSO), are calculated. Then, in the second stage, time-bands of TOU tariffs are computed for each aggregator to incentivize PEV charging in accordance with the result of the first stage. Such time-bands mitigate the increase in aggregator energy costs due to PEV charging coordination. Finally, in the third stage, the obtained TOU tariffs are applied to the PEV coordination methodology. The proposed methodology has been applied to a case study involving 32 aggregators. Results indicate that the increase in aggregator costs due to PDT power limitation is relatively small, while the reduction in LOL of PDT is significant.