Working Principle of a Diesel Generator

A diesel engine drives a generator to convert diesel energy into electrical energy. Within the diesel engine cylinders, filtered clean air from the air filter mixes thoroughly with high-pressure atomized diesel fuel injected through fuel injector nozzles. Compressed by the upward movement of pistons, the mixture's volume decreases while its temperature rapidly rises to diesel's ignition point. When ignited, the combustible mixture undergoes violent combustion, causing rapid volumetric expansion that drives the pistons downward, and this process is termed the "power stroke". As cylinders fire in sequence, the thrust on pistons is transmitted through connecting rods to rotate the crankshaft.

By installing a brushless three-phase synchronous AC generator coaxially with the diesel engine's crankshaft, the engine's rotation drives the generator's rotor. Through electromagnetic induction principles, the generator produces an induced electromotive force, generating electric current when connected to a closed load circuit.

Diesel generator sets represent a type of self-contained AC power supply system - compact independent power generation equipment using internal combustion engines to drive synchronous AC generators. Modern diesel generator sets integrate multiple components into a rigid unit: diesel engine, three-phase brushless synchronous generator, control panel, radiator, coupling, fuel tank, silencer, and common base.

The diesel engine's flywheel housing axially connects with the generator's front end shield through shoulder positioning, forming an integral unit. A cylindrical elastic coupling directly transmits rotation from the flywheel to the generator, with screw-fastened connections ensuring crankshaft-rotor concentricity within specified tolerances. To reduce vibration, shock absorbers or rubber damping pads are typically installed at connection points between major components (diesel engine, generator, radiator, electrical control panel) and the common base.