Siemens Aktiengesellschaft

Siemens Energy Global Gmbh & Co. Kg

Michael Henning

Reinhard Frank

Oldrich Zaviska

Dieter Diegel

Peter Gottfried

Wolfgang Wiesenmüller

Helmut Bescherer

Maria Zeis

A method for operating a power plant having a gas turbine, a heat recovery steam generator, a steam turbine, an auxiliary heat source, and a control system, wherein the method includes controlling the power plant such that the heat recovery steam generator receives an input of heat from the gas turbine; determining the gas turbine is operating at its maximum capacity or at an upper end of its control range and the power plant is operating at less than a target value for a power plant capacity; determining a target pressure value immediately upstream of the steam turbine, wherein the target pressure value is derived from a primary pressure for the steam turbine and a steam turbine capacity for the steam turbine; based upon the target pressure value, controlling the heat store to release heat into the heat recovery steam generator to achieve the predefined power plant capacity.

Method for operating a power plant

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 stem turbine part of a gas/steam turbine installation. To this end, the pressure stage is operated with a control valve () 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 the flow that is increased vis-&#xe2;-vis the throttled condition of the control valve () and acts on the effective area of flow of the control value () 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.

Method for the primary control in a combined gas/steam turbine installation

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Erlangen, Germany

Michael Henning