Method of controlling gas engine and gas engine drive system

A gas engine drive system comprising:

• a gas engine connected to a turbocharger including a compressor and a turbine;
• a fuel injection system that injects a fuel gas into air supplied to the gas engine;
• an ignition system for igniting an air-fuel mixture of the fuel gas and the air;
• and
• a controller that controls the fuel injection system and the ignition system, wherein
• the controller:
• performs a knocking control operation of optimizing an ignition timing as a steady operation;
• and
• in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increases an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retards the ignition timing and then gradually increases the actual fuel injection amount.