Coordinated Charging and Discharging of Electric Vehicles With Multiple Trips

The proliferation of plug-in electric vehicles (PEVs), especially taking vehicle to grid (V2G) into consideration, imposes operational challenges to the existing power systems and thereby calls for effective coordinated load control method. From the perspective of PEV owners, coordinated charging and discharging of PEVs can reduce their energy purchase cost and V2G enables them to participate in the energy and ancillary markets. In this paper, the aggregate PEV charging and discharging power and energy models are built first considering the trip chains of PEVs within a whole day. A coordinated PEV charging and discharging strategy is then proposed to reduce the total charging cost and promote the integration of PEVs and distributed generation (DG). Simulation results show that the proposed charging and discharging strategy for PEVs can effectively reduce the costs for PEV users, promote the integration of photovoltaic (PV) generation, and smooth the total load profile.

I. Introduction

For the sake of ameliorating climate change and energy crisis, sustainable development has been placed on the agenda by many countries. It is exigent to supplant traditional energy with alternative energy sources. Increasing the penetration rate of the supply of renewable energy and popularizing plug-in electric vehicles (PEVs) are widely recognized as two effective solutions to reducing the dependence of fossil fuels and alleviate global warming [3]. However, high penetration of distributed generation (DG) to power systems brings problems such as reverse power flow and voltage deviations.