Control of an engine-driven generator to address transients of an electrical power grid connected thereto

An apparatus comprising:

• an electric power generator configured to couple to an electric power grid;
• a spark-ignited internal combustion engine to drive the generator;
• a sensing device;
• and
• a controller responsive to the sensing device to regulate operation of the generator and the engine, the controller being configured:
• to determine a low voltage condition of the electric power grid, and
• in response to the low voltage condition, to
• provide one or more output signals to change spark ignition of the engine and adjust a field of the generator, the changing of the spark ignition including retarding a timing of the spark ignition so as to reduce power output and preserve synchronization with the utility grid,
• wherein the retarding the timing of the spark ignition comprises modulating the timing between a maximum retarded timing and a nominal timing based on a speed of the engine during the low voltage condition.

A method, comprising:

• providing electric power to a utility grid, which includes driving a field-adjustable alternator coupled to the grid with a direct injection compression-ignition internal combustion engine with fuel injection;
• detecting a low voltage condition of the utility grid;
• in response to the low voltage condition:
• changing ignition of the engine by altering the fuel injection, the altering of the fuel injection including retarding a timing of the fuel injection so as to reduce engine power output and preserve synchronization with the utility grid;
• and
• adjusting a field produced by the alternator,
• wherein the fuel injection is altered when a speed of the engine exceeds an upper threshold, and
• wherein the fuel injection is restored to an unaltered state once the speed drops below a lower threshold.

An apparatus comprising:

• an electric power generator configured to couple to an electric power grid;
• a compression ignition internal combustion engine to drive the generator, the engine including one or more cylinders with fuel injection;
• a sensing device;
• and
• a controller responsive to the sensing device to regulate operation of the generator and the engine, the controller being configured:
• to determine a low voltage condition of the electric power grid, and
• in response to the low voltage condition,
• to provide one or more output signals to change the fuel injection to alter engine ignition and adjust a field of the generator, the changing of the fuel injection including one or more of halting injection, reducing an amount of injected fuel, and retarding injection timing on one or more cylinders of the engine so as to reduce engine power output and preserve synchronization with the electric power grid,
• wherein the fuel injection is changed when a speed of the engine exceeds an upper threshold, and restored to an unaltered state once the speed drops below a lower threshold.