1
Takao Kuwabara, Hisao Inoue, Hiroto Nakagawa, Eizo Kita: Variable speed pumping-up system. Hitachi, The Kansai Electric Power, Fay Sharpe Beall Fagan Minnich & McKee, June 25, 1991: US05026256 (48 worldwide citation)

The operation of a variable speed electric driven pump turbine is monitored continuously during pumping to detect the operation point of the pump turbine, and to prevent it from falling into a hump characteristic region, which is recognizable on a graph of total dynamic head versus flow rate. Stalli ...


2
Akihiro Sakayori, Takao Kuwabara, Akira Brando, Yasuteru Oono, Shigeaki Hayashi, Isao Yokoyama, Kenzyu Ogiwara: Variable-speed pumped-storage power generating system. Hitachi, Fay Sharpe Beall Fagan Minnich & McKee, March 28, 1989: US04816696 (39 worldwide citation)

A variable-speed pumped-storage power generating system includes a variable-speed generator/motor, a frequency converter connected to an electric power system, and a pump/turbine driven by the generator/motor. The power generating system comprises an optimum rotation speed function generator calcula ...


3
Takao Kuwabara: Method and apparatus for controlling variable-speed hydraulic power generating system. Hitachi, Beall Law Offices, November 25, 1986: US04625125 (32 worldwide citation)

A method and apparatus for controlling a variable-speed hydraulic power generation system using an induction generator of wound-rotor type is disclosed, in which variation in frequency of the power system connected to the power generation system or power demand from the power system is detected and ...


4
Junichi Shiozaki, Akira Bando, Takao Kuwabara, Eiji Haraguchi, Hiroto Nakagawa: Control apparatus for variable-speed hydraulic power generating system. Hitachi, The Kansai Electric Power Co, Fay Sharpe Beall Fagan Minnich & McKee, June 28, 1988: US04754156 (30 worldwide citation)

Disclosed is a control apparatus for a variable-speed hydraulic power generating system comprising a variable-speed a.c. electric generator connected to an a.c. electric power system and a hydraulic machine system including a water turbine for driving the generator and a guide vane for controlling a ...


5
Takao Kuwabara, Hiroto Nakagawa, Eizo Kita: Control system for a variable speed hydro-power plant apparatus. Hitachi, Kansai Electric Power Co, Fay Sharpe Beall Fagan Minnich & McKee, April 24, 1990: US04920277 (21 worldwide citation)

A variable speed hydro-power plant includes a pump turbine (2) having a S-shaped characteristics at the turbine operation. A current time turbine operating point is grasped on a turbine characteristics diagram of the pump turbine (2). A limit operation characteristics curve (nr) of the pump turbine ...


6
Takao Kuwabara, Akira Bando, Eiji Haraguchi, Hiroto Nakagawa: Control system for variable speed water-wheel generator apparatus. Hitachi, Fay Sharpe Beall Fagan Minnich & McKee, April 18, 1989: US04823018 (21 worldwide citation)

A control system for a variable speed water turbine generator apparatus includes a first function generator that is responsive to an output command signal. The first function generator produces a rotation number command signal. A speed adjuster produces an output signal in accordance with a differen ...


7
Takao Kuwabara, Eizo Kita: Pump system operable by variable-speed control. Hitachi, Kansai Electric Power, Fay Sharpe Beall Fagan Minnich & McKee, November 3, 1992: US05160244 (18 worldwide citation)

A variable-speed pump system comprising: a hydraulic machine having a flow adjusting means and including at least a pumping function; a rotary machine operatively connected to the hydraulic machine and including at least a motor function for rotating the hydraulic machine; a frequency converter for ...


8
Takao Kuwabara: Solid-state radiation detector in which signal charges are reduced below saturation level. Fuji Photo Film, Sughrue Mion PLLC, February 4, 2003: US06515286 (14 worldwide citation)

In a radiation detector: a CsI:Tl (or CsI:Na) scintillator receives a number X of radiation quantums for each pixel, and emits a number L of photons constituting fluorescent light in response to each radiation quantum; photoelectric converters containing Si (or Se) as a main component are arranged c ...


9
Takao Kuwabara: Method, apparatus, and program for image processing. FUJIFILM Corporation, Sughrue Mion PLLC, February 2, 2010: US07657112 (13 worldwide citation)

Generation of ringing components during extraction of striped blue components from an image is suppressed, in an image processing apparatus for removing striped blur components from the image. A preprocess is executed on an image data set, which is obtained by detecting light with line sensors that ...


10
Takao Kuwabara: Method of and system for controlling hydraulic turbine. Hitachi, Beall Law Offices, October 9, 1984: US04475334 (12 worldwide citation)

A method of and system for controlling a hydraulic turbine including a variable throttle valve located in fluid channel upstream or downstream of the hydraulic turbine adapted to be closed simultaneously as guide vanes of the hydraulic turbine are closed at a velocity higher than a predetermined vel ...



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