PURPOSE: To reduce the capacity of a cycloconverter by correcting a guide-valve opening command value so that the speed of rotation at the stationary time is kept outside the output forbidden band of the cycloconverter.
CONSTITUTION: A power controller 17 transmits a control command over a cycloconverter 3 connected to a secondary winding 1b for a winding type induction motor 1 in response to a deviation ΔP between a generating output command P0 and a generating output PG. On the other hand, a hydraulic-turbine characteristic function generator 5 outputs an optimum rotational-speed command Nao and an optimum guide-valve opening command Yao in response to the generating output command P0 and a water-level detecting signal H. A hysteresis function generator 19 outputs a rotational-sheep command Na at an upper limit or a lower limit in the output forbidden band of the cycloconverter when the optimum rotational-speed command Nao is kept in the fobidden band. The sum of a deviation ΔN between the rotational-speed command Na and the speed of rotation N and the optimum guide-valve opening command Yao is transmitted over a drive 8 for a guide valve 9 in a hydraulic turbine 2.
NAKAGAWA HIROTO
ONO KENICHI
BANDO AKIRA
KUWABARA HISAO
HITACHI LTD
| JPS5972998A | 1984-04-25 |