| 摘要 |
PURPOSE:To minimize the load fluctuation during changeover and enhance the stability of system by regulating the opening of each steam regulating valve so as to keep the load constant in the direction in which the opening conforms to the flow rate to valve opening characteristics after the changeover, when the governing system of a steam regulating valve is changed over. CONSTITUTION:A regulating valve opening request signal from the ordinary control function of a turbine is input in throttle governing changeover function 2a through 2d and nozzle cut-out governing changeover function 3a through 3d, and the signal from each changeover function is input in valve opening regulating function 6a through 6d via low selecting circuits 7a through 7d. Hereupon, bias 4a through 4d and 5a through 5d are added to the valve opening request signal. When a governing system is changed over, each bias value is gradually changed while keeping the total steam flow rate constant in accordance with the characteristic of steam flow rate to opening. Thus, the load fluctuation at the time of changeover can be minimized.
|
