Northern utilities optimize lightning arrester placement

摘要

In 1994, Minnkota Power (Grand Forks, North Dakota, U.S.) embarked on a program to improve power quality within its system. The scope of the project was to provide a method of increasing system reliability by reducing lightning-caused outages. The initial plan was to add lightning arresters to the existing 69-kV transmission lines, add fault-locating distance relays and use a realtime lightning-detection system. Arrester and relay installation began in 1995, and by 1999, Minnkota Power had installed 30 fault-locating distance relays and more than 360 miles (579 km) of arresters to its transmission lines. The utility used the real-time lightning-detection system for one year before it was discontinued because of limited application. When Minnkota Power implemented the initial plan, it decided it would review the program after a couple of years to determine its effectiveness and to make any necessary modifications or changes. The utility conducted preliminary studies in 1996 and 1999, and more complete analysis in 2001. This current study contains five years of lightning and operations data from 1996 to 2000.