With the rapid development of wind power and solar PV power

the frequency regulation resource in power system is more and more important. Inverter based Energy Storage System(ESS) technologies such as battery energy storage

flywheel energy storage

and super-capacitor energy storage have fast response capabilities

which assisting coal-fired generation unit in frequency regulation is a significant technical means to improve the frequency regulation performance of coal-fired generation unit. Firstly

this paper introduces the principle of coal-fired generation unit & ESS hybrid system in power grid frequency regulation; Secondly

the control strategy and method of coal-fired generation unit & ESS hybrid system participation in power grid frequency regulation are introduced; Finally

the primary frequency regulation output of coal-fired generation unit & ESS hybrid system is verified and discussed.