Heat pump energy storage system

The invention relates to a heat pump energy storage system, the operation of the heat pump energy storage system is divided into a charging cycle and a power generation cycle, the charging cycle consumes electric energy to generate high-temperature heat energy and low-temperature cold energy, the heat energy and the cold energy are respectively stored by using a heating medium and a refrigerant, and the power generation cycle generates power by using a high-low temperature difference established by the heating medium and the refrigerant, so that electric energy storage is realized. By controlling the number of stages of compression and expansion in the system, it is guaranteed that the low temperature is not too low while the high temperature is obtained in the charging cycle, and the power generation cycle is fully matched with the high temperature and the low temperature generated by the charging cycle. The system has the characteristic of high charge and discharge round-trip efficiency, the refrigerant doe