MODEL-BASED COMBINED CYCLE POWER PLANT LOAD CONTROL

摘要

A control system uses a modeled steam turbine megawatt (power) change attributed to a gas turbine demand change (i.e., a steam turbine to gas turbine transfer function) within a conventional closed loop feedback control scheme to perform control of a combined cycle power plant. This control system implements a form of internal model control and provides better unit megawatt (power) set-point tracking and disturbance variable rejection for overall more robust control, and thus operates to optimize the gas turbine operation of the combined cycle power plant in a manner that provides cost savings over time.

主权项

1. A power generation system, comprising:
a gas turbine power generation unit having a gas inlet, a gas burner coupled to the gas inlet to create combusted gas, a gas turbine coupled to the gas burner and powered by combustion of gas in the gas burner, and a combusted gas exhaust; a steam turbine power generation unit having a steam inlet system, a steam turbine coupled to the steam inlet system and powered by steam from the steam inlet system, and a steam outlet, wherein the steam inlet system is coupled to the combusted gas exhaust to absorb heat from combusted gas in the combusted gas exhaust to produce heated steam within the steam inlet system; an electrical energy generation unit mechanically coupled to the gas turbine and to the steam turbine to produce electrical energy based on movement of the gas turbine and the steam turbine; and a control system that develops a gas turbine control signal to control the combustion of gas within the gas burner to thereby control the electrical energy produced by the electrical energy generation unit, wherein the control system includes a controller, a process model, and a controller input signal generation unit, wherein an input of the process model is coupled to an output of the controller to produce a predicted steam turbine output, and the controller input signal generation unit develops a controller input signal for the controller by combining the predicted steam turbine output, a load set point, a measured gas turbine output and a measured steam turbine output.