Optimal Models Of Capacity Planning And System Operation For CHP Microgrids Incorporating Heat Pumps

Microgrids arouse widespread concern as an excellent renewable energy integration pattern at home and abroad. To further improve microgrid renewable energy consumptive proportion becomes a hot issues of industry and academia. Therefore, this paper introduces heat pump apparatus to consume redundant wind power and bear part of the heat load in cogeneration heat and power microgrid. This paper has developed a strategy of cogeneration heat and power microgrid incorporating heat pump, and conduct research on configuration optimizing and optimal economic operation in cogeneration heat and power microgrid. The main contents are as follows.First, the advantage of introducing heat pump system into cogeneration heat and power microgird is analyzed. In order to reduce conventional energy consumption and abandoned wind power, an operation strategy for cogeneration heat and power microgird incorporating heat pump is developed, a mathematical model of microgrid containing wind turbine generator、cogeneration units and energy storing device is set up. Considering operating principles that the heat pump using for building heating and cooling works, potential economic benefits as introducing heat pump in micro-cogeneration grid is also analyzed.Second, a capacity optimization configuration model in micro-cogeneration grid in area with cold winter and scorching summer is set up. On the basis of the total cost of equipment investment cost、operation and maintenance cost、fuel consumption cost and abandoned wind power punishment costs, a cogeneration heat and power microgrid power capacity optimization allocation model is set up, genetic algorithm is used to solve the problem. In an example analysis using a year as a cycle, Results indicate that introducing heat pump will decrease the quantity of the CHP units and the lead-acid batteries, and increase the capacity of wind turbines, significantly reducing fuel costs and the loss of abandoned wind power, which brings significant economic benefits under the circumstances that system investment remains unchanged.Third, on the basis of capacity optimization configuration, a short-term optimal economic operation model of cogeneration heat and power microgrid incorporating heat pump is established. Aiming at minimizing the total costs of the operation and start-up costs of CHP unit, costs of energy storage loss and abandoned wind power punishment costs, particle swarm algorithm is used to solve the model. Using 24 hour as dispatching cycle, the result shows that adding heat pump can not only reduce abandoned wind power, but also reduce fuel consumption of CHP unit. As a result, the total cost in the micro grid scheduling cycle is significantly reduced.Last, On the basis of the optimal model of economic operation, the influence of coefficient of performance of heat pump on operation economy of microgrid is analyzed. Keeping the micro grid other parameters constant and making the coefficient of heat pump energy efficiency changes within a certain range, we can solve the optimal model of economic operation in different coefficient of energy efficiency. The result shows that increasing heat pump efficiency factor can improve the economic benefit of micro-cogeneration grid, however when the energy efficiency coefficient exceeds a certain value, the increase of its does not significantly reduce the system total operation cost. So we should comprehensively consider the investment cost of heat pump and system operation cost when we choose heat pump.