Patent ID: 8344550

Claim:
A power generation system comprising: a renewable power source for producing source power; a source side converter for converting the source power to converted DC power; a source side controller for driving the converted DC power towards a maximum power point; a DC link for receiving the converted DC power; a grid side converter coupled to the DC link for converting DC link power from the DC link to AC output power for a grid; a grid side controller for controlling the AC output power of the grid side converter to achieve grid interconnection requirements; an electrical energy storage device; an energy storage converter coupling the energy storage device to the DC link; an energy storage controller for controlling the energy storage converter to achieve a desired power balance on the DC link, a state of charge (SOC) manager for receiving a SOC signal from the energy storage device and, if the SOC signal is lower than an acceptable SOC operating range, for enabling charging of the energy storage device by providing a grid side low SOC adjustment signal to the grid side controller to reduce the AC output power and/or providing a source side low SOC adjustment signal to the source side controller to increase the source power, and, if the SOC signal is higher than the acceptable SOC operating range, for enabling discharging of the energy storage device by providing a grid side high SOC adjustment signal to the grid side controller to increase the AC output power, by diverting power from the DC link to a braking resistor, and/or by providing a source side low SOC adjustment signal to the source side controller to reduce the source power, wherein the source and grid side controllers each operate independently when the SOC of the energy storage device is within the acceptable SOC operating range.