Combined Cycle Power Plant Control During Frequency Excursions

Combined cycle power plants (CCPPs) have unique frequency response compared with conventional steam turbine power plants, because gas turbine power output is determined not only by speed but also temperature controller. In the paper, special attention will be devoted to CCPP operation under low frequency conditions. In this mode operation of CCPP controllers can result in frequency collapse. In the paper, the method is presented allowing elimination of undesired frequency conditions. It is based on active power boosting, which should be introduced at the first moment of frequency drop.