Capacity Optimization Of Energy Storage Unit In Distribution Generation System Considering Electric Vehicle

Nowadays, because of the environment pollution and the increasing of energy exhaustion, the application of distributed generation has become a hotspot of the whole world. Distributed generation has the advantages of eco-friendly, high efficiency and saving the initial investment, etc. Compared with the conventional energy, the distributed power system has the impact on the stability of power system as its uncontrollable and random characteristics. The energy storage technology is an effective way to improve the effectiveness of distributed generation systems which can provide the energy buffer, the reserve balance and back-up for distributed power. With the development of electric vehicle technology, especially the battery technology and the support of relevant national policies, the growing number of electric vehicles connect to the distributed power generation system. As electric vehicle is a kind of removable energy storage and vehicle, it is necessary to analyze the characteristics of distributed powers and electric vehicle models and study the access of electric vehicle impact on the configuration of the capacity of energy storage device.Firstly, according to the working principle of distributed power, several distributed models such as photovoltaic cell, wind power, fuel cell and lead-acid battery are established by the Visual C++programming software. Their associated output or volt-ampere characteristics are simulated through these models. The experimental results show that these models can reflect the characteristics of these types of distributed power and can be used in the following studies.Secondly, as the electric vehicle is a special transport, when it is as a load only, its high-volume access to grid charging will have some impacts on the stability of power system; when it is as an energy storage device in a suspended state, it can be complementary regulation with distributed power supply. Taking advantage of this complementary characteristic, it can get together remaining power in suspended vehicle battery to inject to the distributed generation system when requiring power; However, the distributed generation system can charge vehicle battery when its power is surplus. Thus, it can achieve complementary dispatch and improve the system stability. At the same time, electric vehicle classification, the three commonly used charging modes and the impact of its access to the grid power are briefly introduced. The statistical model of the electric vehicle power demand is also established.The researched results show that electric vehicle can increase the peak load of the grid as a large-scale charging load connecting to the grid, while increasing the capacity of the energy storage system unit and the cost. However, it can improve the distributed power utilization and gentle load curve through the use of V2G technology and corresponding dispatching strategies.