Earthquake Monitoring System for the Electrical Substations in the South Korea

KEPCO (Korea Electric Power Corporation) Research Institute has developed earthquake monitoring system that provides earthquake ground-motion (GM) intensities at the sites for the nationwide 900 high-voltage (154/345/765kV) electrical substations in the South Korea. The GM intensities at the site can be used to evaluate the earthquake induced damage status of the electrical facilities. For now, only 56 electrical substations are equipped with seismometers that could directly provide the earthquake GM intensities at the sites. In order to indirectly monitor the other numerous electrical substations, the KEPCO earthquake monitoring system is integrated in real-time with the national seismic networks composed of ~ 300 seismic stations around the nation. The KEPCO earthquake monitoring system is designed to estimate the damage status of the 900 high-voltage electrical substations within 10 minutes after the earthquakes event based on the earthquake source parameters such as the earthquake magnitude, location, and the time of occurrence that are provided on-line by the Korea Meteorological Administration. The quality control of the seismic records from the electrical substations equipped with seismometers is frequently and automatically performed by comparing nearby seismograms from national seismic stations for the small earthquakes (M > 2.0) that occur 2–3 times per month. If the poor quality of data is found, the GM at the site can be predicted by using nearby (<30km) national seismograms. KEPCO has a plan to utilize the earthquake early warning service from the Korea Meteorological Administration and expand the earthquake monitoring system for electrical substations to the large-scale power plants sites including fossil and nuclear power plants. In the end, these efforts will contribute to enhancing the resilience of the power grid from the earthquake disaster in the South Korea that has the disadvantage of single large isolated power grid network.

I. Earthquake Damage of Power Facilities

Earthquakes are unpredictable and the uncertain natural phenomena require appropriate initial rapid response in the event of an earthquake of power facilities. For this purpose, many related departments and representatives must quickly share accurate earthquake damage information. In general, the earthquake damage of power equipment occurs when the earthquake ground-motion levels in the power facility site located near the earthquake exceeds the seismic design criteria of the facility. Power equipment is a facility necessary to deliver power produced in the power plant to the various acceptor through transmission lines, substations and delivery networks. These facilities are linked nationwide like neural networks, and if an earthquake damage occurs in some facilities, it can cause a wide range of power outages even in remote acceptors, which can lead to complex disasters with enormous social and economic ripple effects. Therefore, earthquake damage monitoring of power facilities cannot be limited to specific facilities, but should be targeted for wide-area facilities scattered nationwide. The most ideal way to monitor earthquake damage is to use seismometers installed at the facility site. However, in cases where the number of facilities subject to monitoring is numerous, such as power facilities, direct earthquake monitoring through the installation of seismometers in the facilities is practically impossible, necessitating the development of related technology.