Research on dispatch scheduling model of micro-grid with distributed energy

Abstract

With the increase of distributed energy connected into power grid, the traditional power gird is changing from centralized control into interactive power system with two-way flow of information and energy. Both the distributed generation and electricity from power grid can meet the load demand of this micro-grid system. So it is quite different from the traditional dispatch model consisted of power generation, transmission, dispatching and consuming. In order to ensure the safety of power grid and the optimization of micro-gird, it is needed to research a power grid side dispatch scheduling model of the micro-grid. In this work, a micro gird, which can purchase electricity from power grid, is presented. This micro grid also contains other distributed energy including solar photovoltaic arrays, wind turbines, micro turbines, and storage batteries, self-owned power plants. The operation object of the micro-grid is to minimize the total cost which contains the distributed energy generation cost, electricity purchase cost and sewage cost. From the power gird point of view, this micro-grid can be tread as a load. So in the case of minimizing the total cost, the electricity demand of the micro-grid should be studied carefully in order to establish a dispatch scheduling model. In this work, the output power of solar photovoltaic arrays, wind turbines, micro turbines, and storage batteries, self-owned power plants are modeled separately according to their power generation features. Considering the volatility of the wind speed, a rolling real-time forecast is used in wind power model. Also the impact of real-time lighting and the temperature of the panels are considered, when modeling the power output of the photovoltaic array. Furthermore, in the model, safety constrain conditions are added to solar and wind power to limit their impact on the safety of power gird. Then the 24-hour electricity demand of this micro-gird under different electricity price level can be figured out, which is helpful for operators in power grid control center to operate and control of this interaction power grid.