Hitachi, Ltd.

The Chugoku Electric Power Co., Inc.

Chugoku Electric Mfg. Co., Ltd.

Eichi Okamoto

Shingo Shirakawa

Seizo Nakano

Seiichi Maruyama

Kenji Kohara

Makoto Matsuzaki

A mounting construction of a tank-type lightning arrester for a neutral point of a transformer includes a transformer having a transformer winding contained within a transformer tank, the transformer winding having a neutral point, and a tank-type lightning arrester having an overvoltage protection element contained within a lightning arrester tank. A first opening is formed in an upper portion of a side surface of the transformer tank, and a second opening is formed in the lightning arrester tank, and the first and second openings are connected together through an insulating spacer having a central conductor, and the neutral point of the transformer winding is connected to the overvoltage protection element via the central conductor. The lightning arrester tank is supported solely by a mounting portion provided on a side surface of the transformer tank.

Mounting construction of a tank-type lightning arrester for a neutral

A transmission line protection system arranged such that a leakage current detector is provided at an end of an insulating device such as an insulator connected at one end to a corresponding one of arms of a steel tower and connected at the other end to a transmission line of each phase, thereby detecting an arrester leakage current flowing in the transmission line of each phase, an output signal of the leakage current detector being led to a repeater through an optical fiber cable, an output of the repeater being transferred to a control/supervisory board in a substation through an optical fiber cable. In the control/supervisory board, preferably, a received digital signal which was converted from an analog signal at said leakage current detector is displayed on a cathode ray tube. In such an arrangement, it is possible to smoothly perform supervision of the status of the transmission lines without causing maloperations due to influences from the transmission lines.

Transmission line protection system

Growing community of inventors

Hiroshima, Japan

Eichi Okamoto