Static starting device for the start-up of the gas turbine using position sensorless control method

Static starting devices, also called static frequency converters (SFCs), have been utilized to start gas turbines in gas turbine combined cycle (GTCC) power plants, etc. In general, a gas turbine is started using a generator as a synchronous motor with a single-shaft arrangement that is rotated by the electric power fed from the SFC. Because the rotor position signal of the generator is indispensable for controlling the SFC, a mechanical position sensor is installed beside the rotor shaft. However, such mechanical position sensors require considerable time for installation and adjustment at the site. Therefore, a sensorless control method called the advanced position sensor (APS) has been developed and applied to an SFC. In this paper, we describe an SFC that employs this position sensorless control method. Further, we investigate the applicability of the APS by comparing the pulses of the two systems-APS and the traditional position sensor- observed during start-up.