Model-based micro-grid modeling and optimal PEV charging control

Micro-grid systems can support distribution network to avoid insufficient electricity supply by effectively integrating renewable energy sources and energy storage systems. This paper studies the modeling of a micro-grid system using SimPowerSystems in Matlab/Simulink environment. The Micro-grid consists of ten Electric Vehicle Service Equipment (EVSE), a Photovoltaics (PV) farm, an Energy Storage System (ESS), and a commercial building. To minimize charging cost as well as limit the micro-grid peak load, the Non-Integer Generic Algorithm (NIGA) optimization method is used to obtain optimized Plug-in Electric Vehicle (PEV) charging/discharging schedule with time-varying charging rate. The time-of-use (TOU) price and discharge incentive are applied to implement the cost minimization. The simulation results show that the total load is flattened corresponding to TOU price structures. The optimization that considers both discharge incentive and micro-grid load limit can generate a cost-power win-win result.