Research on dynamic characteristics and control strategy of energy release process of liquid air energy storage system

The liquid air energy storage (LAES) technology has received widespread attention for its advantages of high energy storage density, a wide range of applications, safety, environmental protection and hygiene, flexible device regulation, and large energy storage scale and is developing toward high-parameter and large-capacity energy storage. However, due to the late start of research in China, large-scale LAES has not been put into commercial operation so far, and the lack of in-depth understanding of the dynamic characteristics of LAES has seriously impeded the development of the system design and regulation technology, which limits the development and popularization of LAES. In this study, a dynamic mathematical model of the liquid air energy storage system is established based on the SIMULINK platform of MATLAB software. The dynamic characteristics of the system in the energy release stage are analyzed, a control model of the grid-connected speed control system is established, and an optimized control strategy is obtained by using a linear active disturbance rejection controller and by analyzing the response under typical disturbances. The model and the results of this study provide a reference for the understanding of the dynamic characteristics of LAES and the control of the speed control system, and the control strategy can effectively reduce the problem of high overshooting of the rotor of the expander and reach a stable state in a shorter time, which is of practical significance for promoting the application and popularization of LAES.