Distribution Networks Planning Containing Micro-grid And Electric Vehicle Charging Facillties

Electric vehicles(EVs) use electric power instead of fossil fuels,and this can greatly reduce pollutant emissions. Government has introduced a variety of policies to encourage the development of electric vehicle industry, and the "100city1000EVs"project has been launched.These measures promote the EVs charging facilities and other infrastructure facilities construction to develop rapidly. Using photovoltaic power to generate power is considered an effective way to solve the energy crisis. But its high cost limits the development. The efficient of Microgrid which is consists of photovoltaic power generation and EVs charging facilities is proved higher from using energy. However, distribution networks planning containing such microgrid becomes more complex in load forecasting, connection modes, and modeling. Distribution networks planning workers will force more challenge.The conclusion is drew through analyzing the mathematical model of the PV array and its output characteristics that temperature and sunlight intensity are the major factors that effect the output of PV array. Charging time and charging models of four types of EVs(buses,taxis,service car and private car)are analyzed,and the load characteristic of EVs charging facilities is given while the numbers of four types of EVs are known. One year is divided to three parts that summer is one part, winter is one part, spring and autumn is the last part. One day containing24hours is also divided to five parts. Then the load characteristic of microgrid and EVs charging facilities can be known. Finally, this unsure load can be used in the distribution networks planning model by this way.This paper makes substation sites planning model is made for minimizing the distance from loads to the substation that supply power to the loads. And networks planning model is also made for minimizing the investment and the cost of operating and losses. Maximum load of microgrid and EVs charging facilities is used to ensure reliability. To prevent two-way flow, one constraint condition is considered that microgrid can not sent back power. An improved particle swarm optimization algorithm is used to solve the nonlinear planning model.Finally, take distribution networks planning of a regional for an example. By using the planning model raised in this paper optimized distribution networks planning program is got.