METHOD FOR THE PRIMARY CONTROL IN A COMBINED GAS/STEAM TURBINE INSTALLATION

摘要

The aim of the invention is to improve a method for the primary control so that reserve power that is practically completely available for the effective frequency boost within seconds is available also in the steam turbine part of a gas/steam turbine installation. To this end, the pressure stage is operated with a control valve (6, 7, 8) that is throttled to such an extent that a frequency boost power reserve is built up. Said power reserve is used for frequency boosting in the event of an underfrequency by correcting the desired value depending on the underfrequency. Said corrected value corresponds to an effective area of flow that is increased vis-à-vis the throttled condition of the control valve (6, 7, 8) and acts on the effective area of flow of the control valve (6, 7, 8) with an impressed signal that approaches zero after a predetermined time. Said signal is chosen in such a manner that, despite the correction of the desired value, a stable operative condition is maintained in accordance with the response behavior of the gas/steam turbine installation to the increased effective area of flow.