| 摘要 |
PURPOSE:To improve the follow-up performance at a time of a speed up operation by allowing a regulating valve to be kept open before the number of revolution reaches a value within the stated range of deviation at the early stage of a start-up operation of a steam turbine so that a PI blind controller is shifted to a control mode after the PI blind controller is permitted to track an actual valve opening. CONSTITUTION:A deviation signal C between the set number of revolution NR and an actual number of revolution N is inputted into a PI blind controller 13 allowing the control signal to be transmitted to a regulator valve drive device through a signal selector 27. A signal selector 26 determines the initial opening LGVI of a steam regulating valve as a function of steam pressure PL or PH in such a manner that the output from a function generator 23 is selected when low steam pressure PL exceeds the reference value PLT, and the output from a function generator 24 is selected when PL is lower than PLT. On start-up command St being inputted, a flip-flop 30 is set up, the PI blind controller 13 is in a tracking mode allowing a discriminator 28 to be initiated when both speed up and deviation in the number of revolution and become smaller. Subsequently, this allows the flip-flop 30 to be reset permitting the PI blind controller 13 to be shifted to a control mode. |
