Research On Economic Scheduling Strategy Of Microgrid Based On Combined Cooling,Heating And Power

With the continuous development of the global economy, human's dependence on energy is also increasing. Fossil fuels are becoming increasingly depleted, so that the rapid development of renewable energy utilization. Distributed generation is a form of renewable energy production, it will bring some negative factors to the operation of large power grid when directly connected. As a form of operation and organization of power system production and consumption, microgrid plays an important role in the production of renewable energy. It economic dispatch is also different from the large power grid, which needs to be studied and solved according to the operating characteristics of microgrid and the characteristics of microgrid.Based on the analysis of the structure of microgrid bus, the power output model and economic model of microgrid system including wind turbine, photovoltaic array, combined cooling heating and power (CCHP) system based on micro turbine, fuel cell and battery are established. And the method of HOMER software to synthesize the basic data of annual load,wind speed and light intensity is given. Then the mathematical model and scheduling strategy of microgrid economic dispatch are established, which includes the cost objective function and electrothermal equilibrium constraints and inequality constraints for maintaining microgrid security and stability. The total cost as a objective function. Two objective and three objective function of the generation cost classified according to the type of cost and the type of generating unit are given. Based on the constraint conditions of microgrid operation, two economic operation scheduling strategies of microgrid under the operation mode of "ordering power by heat (cool)" and "ordering heat (cool) by power"respectively of the CCHP system are proposed.Through a specific example of microgrid, according to the typical daily load in winter and typical daily load in summer, the two scheduling strategies are adopted in the CCHP system, which are "ordering power by heat (cool)" and "ordering heat (cool) by power",using particle swarm optimization algorithm to scheduling optimization. The results show the effectiveness of the economic scheduling strategy of microgrid.