KAHENSOKUYOSUIHATSUDENSHISUTEMUNONTENSEIGYOHOHO

摘要

PURPOSE:To stably control in high efficiency to a target power by controlling the opening of a governor valve on the basis of an input power value to an induction machine by the correlation between a predetermined input power value to the machine and an efficiency with a head as a parameter. CONSTITUTION:A phase angle calculator 16 calculates the phase angle deltaof an exciting voltage to be applied to the secondary windings 6a-6c of an induction machine in response to a deviation between a power control command P0 and an effective power P. A secondary winding excitation amount setter 17 controls the exciting voltages of the windings 6a-6c on the basis of the number of rotation N and the angle delta. On the other hand, an optimum valve opening calculator 25 outputs a governor valve opening Y to meet a head command H and the power P on the basis of the characteristics of the predetermined power P and the opening Y. A servo system 14 applies an operation amount responsive to the opening Y to a governor valve 12.