Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Naoki Kasahara

Ken Yoshioka

Tokio Yamagiwa

Hiroshi Arita

Masayuki Shibata

Shingo Shirakawa

Tadasi Sonobe

Shinichi Kondo

Hideshi Fukumoto

Teruhiro Takizawa

Satoshi Watahiki

Takahide Matsuo

Fumio Suzuki

Fumihiko Goto

Shigeru Sakamoto

Yoko Kameoka

This invention is to provide a transforming system capable of satisfactorily protecting the equipment of a substation even if a aerial electric power lines is struck directly by an intense electric shock of a large energy, such as an electric shock of a waveform similar to that of a thunderbolt stroke having a long duration of wave tail. So, this invention, a transforming system comprises, a lightning arrester, a ground fault device installed near a service entrance through which the power lines are led in, a voltammeter placed on the gas-insulated switchgear, and a control device receiving a signal from the voltammeter and providing a signal for controlling the grounding device. And when detecting of said thunderbolt arising in said aerial electric power line, a control device which order said ground fault device to make the ground fault condition.

Power transforming system and method

There is disclosed a coil structure which can be rapidly energized or excited, and which reduces the generation of heat in a coil container by an eddy current due to a dynamic disturbance such as vibration and a magnetic field fluctuation, thereby suppressing the occurrence a quench. The coil container is constituted by a low-resistivity material, and a high-resistivity portion is provided at at least one portion of the coil container in the direction of the periphery of the coil container. The high-resistivity portion is provided at a position where a vibration displacement is small or a magnetic field fluctuation is small. When the coil structure is to be energized or excited, the eddy current produced in the direction of the periphery of the superconducting-coil container can be reduced at the high-resistivity portion, and when the dynamic disturbance develops, the generation of heat by the eddy current is suppressed by the low-resistivity material.

Coil structure and coil container

Growing community of inventors

Hitachi, Japan

Naoki Kasahara