Patent ID: 7408268

Claim:
A method for controlling a power supply system connected to a power grid, the power supply system including an electrical power source, the method comprising the steps of: a. delivering power from the power source; b. detecting a characteristic indicating an islanding condition of the power supply system; c. in response to detecting the characteristic indicating an islanding condition, causing a temporary variation in the power delivered by the power source; d. while the power delivered by the power source is temporarily varied, monitoring the power source for a characteristic indicating an islanding condition of the power supply system; e. if a characteristic indicating an islanding condition of the power supply system is detected while the power delivered by the power source is temporarily varied, interrupting the power source to remove the islanding condition; and f. if a characteristic indicating an islanding condition of the power supply system is not detected while the power delivered by the power source is temporarily varied, removing the temporary variation in the power delivered by the power source.