Hitachi, Ltd.

The Kansai Electric Power Co., Inc.

Yasuhiro Yasaka

Osamu Nagura

Yosio Furukawa

Koji Sato

Makoto Suzuki

Hiroto Nakagawa

Masatoshi Watanabe

Yukio Hirama

Yasuteru Oono

Shinsaku Hakuta

Yasuyuki Wachi

Eiji Tsuji

Eiji Haraguchi

Shigeo Higuchi

Tsutomu Iwasaki

Hirotaka Akagawa

A method of assembling a wound rotor of a vertical type adjustable speed electric rotating machine at a power house of a hydroelectric power plant, with the method including a layer of a rotor body on its side into a pit in the power house with a top surface of an outer circumference of the rotor body extending from the pit to a height sufficient to facilitate a carrying out of field coiling assembling operations by working personnel from a foundation of the power house whereby it is possible to limit an increase in the height of the power house to a sum of an axial length of the assembled rotor body and a height of a crane lifting jig.

Method of assembling wound rotor of vertical type adjustable speed

A variable-speed power generating system comprises a variable-speed generator electrically connected at its primary winding to an electric power system and its secondary winding to the electric power system through a frequency converter and mechanically coupled to a driver driving the secondary side thereof, a phase detector generating an output signal representing a slip frequency in response to the application of a first input having a frequency component of an output generated from the primary winding of the variable-speed generator and a second input having a frequency component corresponding to the rotation speed of the driver, a controller controlling the frequency converter on the basis of a reference phase provided by the output signal of the phase detector, and regulating means for controlling the frequency converter so that, when the variable-speed generator is disconnected from the electric power system, the frequency applied to the secondary winding of the variable-speed generator may not deviate from a predetermined allowable range of variable frequency operation of the frequency converter.

Variable-speed power generating system

A rotor for electric rotating machines has a plurality of salient poles arranged in spaced relation in axial direction on the outer periphery of the rotor rim. Adjacent salient poles have opposed slots in the axial direction, into which a shielding member is fitted to bridge between said adjacent poles. The shielding member includes a plurality of rod members fitted over the entire length of said slots to extend across said opposed slots. While the rotor is running, the centrifugal force acts on each of said rod members thereby pressing the rod members against the outer periphery side wall of the slot. As a result, the centrifugal force is dispersed substantially uniformly over the entire length of the slot wall.

Salient pole rotor with shielding rods between adjacent poles

A rotor for electric rotating machines has a plurality of salient poles arranged at certain intervals with each other along the outer periphery of the rotor rim. Each of the shield plates of the rotor has a plurality of reinforcing ribs arranged between adjacent salient poles and extending along the periphery of the rotor. The eddy currents flowing in the shield plates are reduced, thus reducing the eddy current losses.

Rotor with salient poles and shield plates between the poles

Growing community of inventors

Hitachi, Japan

Yasuhiro Yasaka