US Patent 7365444 Active anti-islanding system and method

An engine control system suited for use with an engine that outputs electrical power to a local load and is electrically connected to an electrical grid. The engine generates power at a power output value and the load consumes power at a load value. The engine control system includes a sensor that measures an electrical parameter indicative of a difference between the power output value and the load value, and a master control system that varies the engine power output value to prevent the electrical parameter from reaching zero.