Charging load from large-scale plug-in hybrid electric vehicles: Impact and optimization

In this paper, a stochastic model of large-scale plug-in hybrid electric vehicles´ (PHEV) charging loads is developed in Matlab to investigate its impact on power grid. In this model, two main types of PHEVs are defined: public transportation vehicles and private vehicles. Different charging time schedule, charging speed and battery capacity are considered for each type of vehicles. The simulation results reveal that there are two huge load peaks (at noon and in evening) when the penetration level of PHEVs increase continuously to 30% in 2030. Therefore, optimization is introduced to shift peak loads. This optimization process is based on real time regional pricing and wind power output data, so as to make better use of surplus wind power. With the help of smart grid, power that is allocated to each vehicle could be controlled. As a result, this optimization process could fulfill the goal to shift peak loads to valley areas where real time price is low or wind output is high depending on system operator´s preference.