The Optimal Allocation Of CCHP Type Of Microgrid With Compressed Air Energy Storage System

With the vigorous development of renewable energy, energy storage technology also gets a wide attention as a key way to solve the intermittent and volatility, especially in the application of microgrid. In this paper, a new type of compressed air energy storage system is proposed, which fully utilize the heat/cold generated in the process of gas compression/expansion, and then applies it to CCHP type of microgrid. In order to ensure the high efficiency, cleanliness and stability of CCHP with compressed air energy storage system, the paper mainly studies on the modeling, analysis of the compressed air energy storage system, and the optimal allocation of the CCHP capacity.This paper firstly describes the advantages of compressed air energy storage system, and then focus on the structural design of CCHP type of microgrid with compressed air energy storage system. Moreover, the structure and working principle of compressed air energy storage system with heat recovery is introduced in detail. Based on that, this paper use thermodynamic principle to analyze working performance of compressed air energy storage system, and the mathematical model which is suitable for microgrid optimization is further built. At the same time, models of micro gas turbine, wind power generator and photovoltaic array are also given.Capacity optimization of CCHP type of microgrid with compressed air energy storage comes down to a nonlinear multi-objective optimization problem with constraints due to its multi-variable, complex and stochastic characteristics. To solve this problem, an improved multi-objective optimization algorithm C-NSGA-II is proposed and verified its advancements through convergence and uniformity performance tests.In order to enable decision makers to choose the reasonable allocation plan from a set of pareto optimal solutions, this paper introduces the fuzzy membership function method. And different solution selection schemes are provided to verify the superiority of the best optimal compromise solution solved by fuzzy membership function.In the last section, a multi-objective optimization model is established considering economic cost, power supply reliability and environmental benefits. According to the historical load data of a certain area, a simulation platform system is built in Matlab. The results show that the optimized CCHP type of microgrid can ensure power supply reliability, save economic cost and reduce environmental pollution. In addition, the economic and energy advantages of CCHP type of microgrid with compressed air energy storage system are analyzed quantitatively by using the output of the unit under the given control strategy in this paper.