Patent ID: 8456878

Claim:
A power storage system for supplying power to a load by connecting a power generation system and a grid, the power storage system comprising: a power converting unit operating in one of at least two control modes including a maximum power point tracking (MPPT) control mode in which the power generation system is controlled to generate maximum power and a voltage control mode in which a boosting ratio is adjusted according to a change in an amount of power consumed by a load, the control mode being determined according to the change in the amount of power consumed by the load; a direct current (DC)/DC converter for converting an output voltage of the power converting unit into a DC link voltage; an inverter for converting the DC link voltage into an alternating current (AC) voltage appropriate for the grid; an integrated controller for controlling operations of the power converting unit, the DC/DC converter, and the inverter; and a power measuring unit for measuring the amount of power consumed by the load, wherein the power converting unit operates in the voltage control mode if the change in the amount of power consumed by the load is equal to or greater than a reference amount of power, and operates in the MPPT control mode if the change in the amount of power consumed by the load is less than the reference amount of power.