Matsui M.,Franklin Japan Corporation |
Takano N.,Sankosha Corporation |
Takano N.,Sagami Techno Center
2010 Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2010
This paper discusses evaluation of Lightning Location accuracy of Japan Lightning Detection Network (JLDN). JLDN has observed lightning activities since 1998. It has been said that the nominal location accuracy of JLDN is less than 500 meters in most area of Japan. But, the actual location accuracy of JLDN has not been evaluated. Sankosha Corporation installed lightning video camera system on the roof top of their building in Sagami Techno Center. They have observed lightning with it around Sagamihara city, Kanagawa, Japan. We show some video images and estimate actual lightning location. We compare them with location observed by JLDN. We also discuss the differences between lightning location estimated with video images and lightning location observed by JLDN. Finally, we report the actual location accuracy of JLDN regarding cloud to ground discharges in this paper. © 2010 IEEE. Source
Sekioka S.,Shonan Institute of Technology |
Hayashi T.,Sankosha Corporation |
Miyazaki T.,Electric Power Development Co. |
Sakamoto Y.,Electric Power Development Co. |
Okabe S.,Electric Power Development Co.
IEEJ Transactions on Power and Energy
This paper describes experimental results of flashover characteristics of medium-voltage insulators to support an insulated cable which is used in Japanese power distribution lines. The experimental study is targeted for direct lightning strokes to a shielding wire or top of a reinforced concrete pole in the distribution line. Lightning impulse voltage is applied to a metallic cross arm to represent the direct lightning stroke. 50% flashover voltage, voltage vs. flashover time characteristic and a photograph of the discharge are measured. This paper investigates the flashover characteristics of three types of cable support system such as suspension support, dead-end support and strain support. The flashover characteristics are dependent on the supporting system. Surface discharge on the insulated cable due to the flashover is observed, causes the discrepancy of the flashover characteristics. This paper presents constants in the integration method, which is a flashover model and can consider the influence of applied voltage waveform in order for accurate lightning surge analysis. © 2010 The Institute of Electrical Engineers of Japan. Source
Sankosha Corporation | Date: 2012-03-02
Sankosha Corporation | Date: 2010-09-13
A protection element (e.g., an arrester) protects a piece of equipment to be protected, from surge currents line terminals and an earth terminal. Surge current detection devices are provided on respective conductors connected to the arrester. Each of the surge current detection devices is to detect the surge current penetrated into a conductor for a short period of time, and includes a magnetic flux concentration member by which a magnetic flux produced by the penetrated surge current is concentrated in a given detection area at a high density, and a ferromagnetic material sheet positioned on the given detection area. The ferromagnetic material sheet includes a recording layer which is able to record and erase the penetration state of the surge current. A plurality of microcapsules are arranged in the recording layer, and each of the microcapsules contains a suitable liquid, and a plurality of magnetic particles suspended in the suitable liquid. An orientation state of the magnetic particles is varied by the concentrated magnetic flux, and can be visually recognized.
Sankosha Corporation | Date: 2015-09-21
A surge protective system has a plinth for wiring and is connected between a plurality of line side wires and a ground wire. A plurality of surge protective devices (SPDs) and one surge detector are disposed in parallel and detachably fitted into and attached to the plinth. The plinth has a wiring metal fitting for connecting the plurality of SPDs and the one surge detector. When a lightning surge current enters into the surge protective system from the line side wires, the lightning surge current flows to the surge detector through the SPDs, a 1st plinth contact part in the wiring metal fitting, a connection part and a 2nd plinth contact part. The lightning surge current flowing to the surge detector is discharged to the ground through the ground wire.