Research On Optimal Schedule For Active Distribution Network Considering Air Quality And Power Supply Capacity

With the development of clean and renewable energy, such as wind and solar, var ious Distributed Generation(DG) have been accessed to the distribution network, so t he traditional distribution network` composed of passive network has turned to the Ac tive Distribution Network(ADN) composed of multi-power. On the one hand, the mul ti-power property of ADN will lead to the fact that the distribution network appears bi-directional current. It will produce a certain influence on the power supply capacity o f distribution network. On the other hand, the controlled DG and energy storage unit o f ADN will be involved in the scheduling of the network and it makes the traditional d istribution network more cost-effective and clean. In recent years, the country suffered severe haze frequently, the residential electricity and industrial loads has obvious cha nges and it makes a certain impact on the accuracy of traditional load forecasting. So we conduct the research in the following aspects in this paper:Firstly, we can look for a more accurate Short-Term Load Forecasting method at the condition of frequent severe pollution through studying the influence from air quality index on the power load. This method analyzes the influence of air pollution on the power load and combines the air quality index with Short-Term Load Forecasting. At the same time, historical data is processed by principal component analysis, and then we can get a comprehensive factor. We calculate the correlation degree and weight by the gray relation method based on the comprehensive factor and other influencing factors to calculate similarity and select the similar day. According to the similar day, we use the Extreme Learning Machine to train the data, then we build the model of short-term load forecasting based on weighted similarity and extreme learning machine to forecast the short-term load of power grid. The model can predict the power load in the situation of frequent severe pollution, which conducive to the relevant departments to adjust the grid scheduling in time and improve the technical management level and economic benefits.Then, the distributed generation is processed into different node types by the grid-connected interface types and control strategies. The corresponding mathematical model are established in flow calculation, and the improved forward and backward substitution method is used to calculate the flow. Forward-backward sweeping method is used to calculate the current operating status of maximum power supply capacity which the objective function is maximum load factor based on the flow calculation model flow calculation. This model can calculate the power margin of distribution network for a period of time in the future, thus it provides certain reference about the scheduling and planning of distribution network for the operators.Finally, after considering the indeterminate factors such as load forecasting and t he output power of distributed generation, the multi-objective scheduling optimization model of AND combined with stochastic simulation technique, which considers powe r supply capacity, is set up based on the chance constrained programming. It takes the least running cost of distribution network system, the largest power supply capability and the highest utilization of renewable energy as the objective function. It realizes th e scheduling optimization of ADN and ensures the power supply capacity is the bigge st, so that the pressure of AND is relived.