History

Distance Protection: The Early Developments

This article discussed only the industry's initial approach to protection and selectivity.  The Zoned Voltage Drop Protection...At the beginning of the 20th century, effective protection coordination using overcurrent or directional overcurrent relays was no longer sufficient due to high clearing times and operation with spur lines and rings circuits. Distance protection became the most important protection technology... More

Relion advanced protection & control.
BeijingSifang June 2016