Patent ID: 6767178
Filing Date: 2004-07-27
Classification: F01D,G05B

Abstract:
A method for controlling a steam turbine using a control system comprising a first controller for a value of a main controlled-parameter, a second controller for a rate-of-change of the main controlled-parameter, an actuator for manipulating a position of a steam valve or valves, and a pilot valve modulated by a pilot-valve actuator for the purpose of manipulating the steam-valve actuator, the method comprising:a) receiving a signal proportional to the value of the main controlled-parameter into the first controller; (b) calculating a first output-signal based on the signal proportional to the value of the main controlled-parameter; (c) receiving a signal proportional to the rate-of-change of the main controlled-parameter into the second controller; (d) calculating a second output-signal based on the signal proportional to the value of the main controlled-parameter; and (e) using a combination of the first and second output-signals as a position signal for the pilot-valve actuator.