Bi-level Optimization Operation Strategy For CCHP Microgrid With Compressed Air Energy Storage

Compressed air energy storage(CAES)system involves various energy forms of cooling,heating and power in the operation cycle,so that it can relate to combined cooling,heating and power(CCHP)microgrid,thus the two systems can play their respective advantages totally.The coupling system can not only suppress the intermittent,fluctuating and random characteristics of new energy,but also strengthen the correlation between energy supply and storage systems and improve the comprehensive energy utilization efficiency of the system.However,the principle of multi energy coupling of compressed air energy storage itself is complex,and the combination with CCHP microgrid makes the system architecture and technical implementation of the new system produce a lot of technical problems.Therefore,this paper uses the energy conversion characteristics of the coupling new system to put forward the control strategy of CAES connected to CCHP microgrid.So as to realize the efficient and stable operation of the system and provide the support theory and practical application guidance for promoting the development of compressed air energy storage and CCHP microgrid.Firstly,the basic system structure of compressed air energy storage and CCHP microgrid is described,and the thermodynamic models of key components such as compressor,turbine,air storage and heat exchanger are established.At the same time,analyze the operation mechanism of internal combustion engine generator(ICE),wind turbine,photovoltaic and other energy supply components in CCHP microgrid system.The mathematical models suitable for optimal control are established.Through the above analysis model,it can provide a strong basis for system characteristic analysis and optimal control.Secondly,the characteristics of CCHP microgrid with compressed air energy storage are discussed in detail.The efficiency of the compressed air energy storage system,the state and power of the energy storage,and the power generation efficiency of the internal combustion generator are analyzed.Finally,a bi-level optimization model of coordinative operation of CCHP microgrid with compressed air energy storage is proposed.The upper-level solves the initial value of the optimal gas storage pressure for each energy supply period.Based on the energy efficiency characteristics of the compressed air energy storage system,the non-dominated Sorting Genetic Algorithm(NSGA-?)is used to solve the lower-level output scheduling optimization problem under the condition of determining the optimal initial value of gas storage.The simulation results show that the proposed control strategy is reasonable and feasible.