Study of economic system at compensation for voltage drop utilizing charging power adjustment of electric vehicles

A surge of needs for the low carbon society promotes a spread of electric vehicle (EV). EVs could be charged at night simultaneously, as a result, severe voltage drop may happen. The authors have proposed the method which can compensate the voltage drop caused by EV charging by means of adjusting charging schedules and controlling reactive power. However, though the method can avoid the voltage violation, the method includes the inequality between EVs in other words, the only EV which is in terminal node in distribution system where voltage violation is likely to occur has to decrease charging power because the method is autonomous distributed control which is based on only self-voltage information. In this paper, we formulate a convenience loss of EV owner due to adjust reactive power and charging power. We propose a method to calculate the benefit of the EV owner and the cost needed by the voltage control using the EVs.