Either a conventional motor starting system or a static starting system can be used to accelerate a large gas turbine from standstill to self-sustaining speed. In the motor-starting configuration, the gas turbine rotor is accelerated by a cranking electromotor. In a static starting configuration, a current with a variable frequency is supplied to the generator stator. The synchronous generator then operates — during the start-up — as a synchronous motor, accelerating the gas turbine rotor. The static starting system has a “soft start” capability, i.e., the power required for start-up increases gradually, without surging.
This paper outlines the operating principle of the static starting method. A comparative analysis of the reliability and availability of the conventional motor starting and static starting configurations is presented.