Effective Measures for Load Leveling of EV Charging Considering Convenience of EV Users

Abstract

Large-scale deployment of electric vehicles adds electric load to the power system. Without control of the temporal distribution of EV charging, steep load peaks could arise in the power system. Therefore, we propose two charging algorithms for the purpose of load leveling. The first algorithm uses off-peak rate period. We test this algorithm in two cases: in the first, all EVs are assigned at the same off-peak rate period; in the second, all EVs are divided into two groups, and each group is assigned at its individual off-peak rate period separately. The second algorithm changes the starting time of charging according to the charging duration required for full charge of EV. We test this algorithm in two cases: in the first, charging start time varies linearly with charging duration; in the second, charging start time varies quadratically with charging duration. The results shows that the algorithm that changes the charging start time based on the quadratic function is the most effective for load leveling.