Kabushiki Kaisha Toshiba

Yukio Kanazawa

Hiroshi Furuta

Masahiro Hanai

Susumu Nagano

Hiromichi Ito

Tadashi Mori

Shinobu Sekito

Makoto Tari

Norikazu Arima

Takeshi Tanii

The invention provides a gas insulated switchgear, and a method for detecting arc damage in a part used in a gas insulated switchgear, which detect directly when an electric contact or a peripheral part reaches an initially set wear limit. An insulating nozzle of a circuit breaker contains a marking substance that releases a gaseous substance inside a circuit breaker gas container as a result of wear by an arc. For ensuring heat resistance and insulation properties, the insulating nozzle is ordinarily formed of a fluororesin, but in the present invention, it is formed of the ordinarily used fluororesin having uniformly mixed therein, as the marking substance, a chlorine-containing resin which has excellent heat resistance and insulation properties such as polyvinylidene chloride.

Gas insulated switchgear and method for detecting arc damage in a gas insulated switchgear part

A pair of electric contacts include a pair of first units which are provided on the surfaces of the end sides of the electric contacts, and generate light having first characteristics at the time of opening and closing of the electric contacts, and a pair of second units which are covered with the first units, and generate light having second characteristics differing from the first characteristics when abrasion of the first units reaches abrasion detection positions due to opening and closing of the electric contacts.

Electric contacts, electric contact apparatus and method for detecting abrasion of the electric contacts

A remaining life of a stator coil resulting from galvanic corrosion between different kinds of metals in a rotating machine adopting a water cooling system and remaining life of a stator coil's insulating layer resulting from a wet heat degeneration can be positively and integrally evaluated according to the present invention by sampling a brazing section between the stator coil clip and copper wires, cutting off the sampled brazing section in a copper wire array direction, measuring a joined section brazed with a brazing material as a copper wire direction length and finding an effective sealing length of that brazing section or sampling an insulating layer of the stator coil, finding infrared spectra of the insulating layer, comparing the infrared spectra of the insulating layer of the stator coil with infrared spectra of a healthy stator coil's insulating layer not penetrated by water, finding difference spectra of an ester group of an epoxy resin used as a bonding agent of the insulating layer and predicting a period of water penetration into the stator coil's insulating layer as a wet heat degeneration period, on the basis of the difference spectra of an ester group, with the use of a relation between the difference spectra of the ester group initially found and an aging time.

Method for evaluating a remaining life of a rotating machine coil

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Yokohama, Japan

Yukio Kanazawa