Blackout Unexpected cause Hokkaido Iburi Earthquake September 8th 6:48

The blackout caused almost all of Hokkaido's power outage due to the September East Earthquake in September last year, and the major cause has been the shutdown of the largest thermal power station in Hokkaido. However, the interview with Hokkaido Electric Power Co., Ltd. revealed that unexpected blackout line problems were also involved in the large-scale blackout.

The major cause of the blackout that occurred during the September Eastern Iburi Earthquake in September last year was attributed to the fact that the largest Nakdong Atsuma Thermal Power Plant in Hokkaido was stopped by the earthquake.

However, at the time of the earthquake, the person in charge of power control at Hokkaido Electric Power responded to NHK's interview, and the transmission line supplying power from the hydroelectric power station in the eastern Hokkaido area to Sapporo was short-circuited. I explained that it was caused by the fact that I couldn't send it.

This trouble occurred in the part of the “jumper wire” that avoids short circuiting of the power transmission line with the tower.

Due to the tremendous earthquake vibration, a phenomenon called “arc discharge” occurred between the jumper line and the steel tower, the transmission line was short-circuited, and the power supply from the hydroelectric power station was cut off soon.

In addition to the shutdown of the thermal power plant, the blackout was caused by the fact that the transmission line was cut off and the supply from the hydropower plant was stopped.

In response, Hokkaido Electric Power worked to reinforce the transmission lines, and in the future, even if the same level of earthquake occurs, the supply of power will not be interrupted.

What is “arc discharge”?

The reason why the transmission line was short-circuited was that “arc discharge” occurred.

A phenomenon in which an electric current flows through a gas such as air, accompanied by strong light and heat.

In the earthquake of last year, the jumper line and steel tower approached due to shaking, causing arc discharge, and the circuit breaker automatically activated to stop power transmission to protect the equipment.

As a result, the supply from the hydroelectric power station from Hokkaido, which supported the electricity in Hokkaido, was cut off, leading to a blackout.

Hokkaido Electric Power Company President Fujii “Crushing the cause is important”

Regarding this blackout, President of Hokkaido Electric Power Company Hiroshi Fujii said, “I want to apologize again that almost all areas of Hokkaido were out of power and caused great inconvenience and inconvenience to the people. I think that is important. "