The integration of variable renewable energy sources such as photovoltaic generation or wind turbine has been greatly promoted worldwide to realize the sustainable energy society. The frequency regulation is of prime importance in power systems with a large amount of distributed generators whose generation outputs are uncertain depending on the weather condition. We have developed frequency control strategies based on the virtual synchronous generator for wind turbines or load control of electrolyzer that will be promoted for the hydrogen society, in order to realize the environmental friendly energy system such as microgrids.