| With the innovation and development of the active power distribution network technology, more and more demand side resources will be accepted in the grid in the future. Electric vehicles is a new and booming schedulable resources in the demand side. We can make the use of its schedulability to correctly guide the charging load of electric vehicle charging station and battery-swap station to reduce the adverse effects caused by them, even make it into a favorable effect, to optimize the overall load characteristics of distribution network. Similarly, the energy storage system has the characteristics of flexibility, scheduling and quick response, which can also be used for optimizing the load characteristic of distribution network. Under the above background, this paper will make the use of charging station, battery-swap station and energy storage system to strengthen the interaction between the power grid and the users so that the three schedulable sources can make full use of their source/load characteristics to alleviate the negative impact on the distribution network.Firstly, according to the IEEE 333bus system, in order to minimize daily loss in the distribution network, we establish a mixed integer programming model with the decision variable of access bus and energy storage system output, to design energy storage system capacity allocation and site selection optimization scheme. Analysis of the relationship between the capacity and, the upper limit of the output power of the energy storage system and the network loss.To minimize the total load variance and the total purchasing cost of distribution network, this paper establishes optimization models with the electric vehicle charging station, battery-swap station and energy storage system separately participating in the regulation and control. At the same time, a fuzzy bi-objective optimization of two kinds of single targets is considered. After solving the problem based on nonlinear programming, this paper gets optimal dispatching strategies for charging/battery-swap station/storage system separately participating in the regulation and control. Considering the synergy regulation of charging/battery-swap station/storage system, this paper establishes a joint optimization scheduling model. Joint optimal scheduling strategy shows that joint optimization has a better performance on optimizing compared with respectively optimal scheduling strategy, and can be more scientific and rational on resource allocation optimization.In actual operation, there are many uncertain factors in charging load of electric vehicle charging station and battery-swap station. This paper considered random uncertainty of electric vehicle charging station and battery-swap station, and carried out stochastic power flow calculation based on analytical method and Monte Carlo simulation method. It is concluded that the bus voltage vector changes with the random load fluctuation, and then we can get the probability distribution characteristics and its related digital feature. Then establish the chance constrained programming model of charging/battery-swap station/storage system, formulate and revise the corresponding constraint conditions. According to the conclusion of stochastic load flow calculation, the effect of power fluctuation at random load bus on voltage vector is very small, we can ignore the influence of random fluctuation in the chance constrained programming problem, and then we do not need to transfer the voltage constraint into chance constraint. The results show that the modified optimal scheduling strategy can be used to increase the flexibility of the electric vehicles’ pick-up time. The results show that the modified optimal scheduling strategy can be used to increase the flexibility of the electric vehicles’ pick-up time, which can make the electric car users and charging/battery-swap station operators maintain good cooperation and interaction mechanism. It can not only optimize the load characteristics and economic operation, but also strengthen cooperation and interaction experience between users and the grid, to achieve a win-win situation. |
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