An optimally controlled charging scheme motivating EV owners for supporting grid stability

摘要

Electric Vehicles (EVs) significantly support green transportation while alleviating pressure of oil export and carbon emissions. Abrupt and uncontrolled charging of these active storage units may increase peak loading and cause complications like need for reinforcement of distribution grid to maintain stability. Simultaneous charging scenario, active mostly at peak hours, also increases the charging cost burden on EV owners. To maximize benefits of using EVs, regulated and optimized charging control needs to be provided for vehicles by Load Aggregators (LAs) with the perspective of minimizing charging cost. LA being a commercial entity aims at revenue maximization. Considering this, an optimal EV charging scheduling problem for a LA is developed by considering its revenue and EV owner's demands and costs. Adaptive charging rate or power is proposed for each vehicle to attain grid stability. Static charging scenario is considered in which vehicle movement patterns are known to the LA in advance. The Linear Programming Problem is solved using simplex method in MATLAB. Simulation results based on real electricity price and load data are presented to show the revenue gains and cost savings by optimal charging scheduling. Comparative analysis of LA's revenue and charging costs is carried out for uncontrolled and controlled charging scenarios. Additionally, their sensitivity towards number of vehicles and upper charging rate limit is analyzed. Results show interesting trends regarding the economics of EV charging, grid stability and charging rate control.