Energy storage component plays an important role in the operation and control process of microgrid which consists of wind and solar. It can be used as a main networking power in the islanded operation of microgrid, in order to maintain the system voltage and frequency stability. For energy storage component controller, a tricyclic feedback control strategy which consists of a power ring, a filter capacitor voltage ring and a filter inductor current ring is designed. And its role in the process of the stable operation of the microgrid and the island / network switching is analyzed. A microgrid system including the energy storage components, wind power and photovoltaic is simulated in MATLAB, and an experimental platform is established. Simulation and experimental results show that the control strategy can maintain voltage and frequency stability of the microgrid in islanding, networking, and the process of switching. It can also achieve a smooth switch between island / network mode of microgrid.