Shaft systems of engine generators have been designed conventionally by analyzing the generated torque of the engine body and the load torque of the generator individually, mainly for the steady state. However to deal with the increase in regeneration energy and the instability of the electrical power system in recent years, transient analysis and evaluation of the power system are taking on increasing importance. This paper reports on technology to estimate torque under transient conditions of the power system and upon the occurrence of an accident using coupled analysis of the mechanical system and the electrical power system of an engine generator.
