The “double high” characteristics of new power system make its frequency stability face a huge challenge. Energy storage assisted thermal power unit frequency regulation technology has become a key core technology to ensure the stable operation of the new power system. The mainstream form of energy storage used in this technology

lithium battery storage

suffers from short lifespan and poor safety in use. The features of supercapacitor energy storage like high power

long cycle life

and high security

are highly compatible with the energy-storage requirements of frequency regulation of the energy storage assisted thermal power unit

but the supercapacitor's response to the continuous unidirectional command is poor. Therefore

it is necessary to explore the technical route of hybrid energy storage to achieve complementary advantages of the two types of energy storage. The hybrid energy storage capacity configuration of supercapacitor and lithium battery was studied

the energy storage capacity configuration method based on the actual AGC frequency regulation command was designed

considering the characteristics of power-type energy storage devices and energy-type energy storage devices. Moreover

the frequency regulation performance and economy of three typical capacity configuration schemes were compared

and the optimal scheme was determined. Finally

engineering verification was carried out. The actual operation data show that

the supercapacitor hybrid energy storage system can improve the frequency regulation performance of the thermal power unit by 59.77%

extend the service life of the lithium battery to 3.6 times

and improve the system economy.