Compressed air energy storage is an effective energy storage technology to solve the instability of wind power in distributed energy resources. In this paper, a multistage compressed air energy storage system optimization model is constructed based on the energy conservation equation. Then the system is optimized by differential evolution to improve the system efficiency. Optimal pressure ratios are proposed to distribute the pressures of compressors and expanders. The impact of pressure ratio distribution curve on the system energy efficiency suggests that the change curve of the characteristics vary in different heat exchanger performance. Results show that the change of thermal transfer reactor performance leads to the variety of optimal distribution pressure ratio and energy efficiency of the system. In addition, the differential ratio distribution factor can be effective on the pressure ratio of reasonable allocation. System efficiency optimization results increased by about 1% compared mean value.
