Over and undervoltage protection of weakly interconnected HV long line networks

The authors describe the voltage slide protection scheme is designed to maintain acceptable voltages to the majority of customers, who are situated electrically distant from a major generating pool, following multiple outage contingencies on the interconnecting transmission system. This is done by maintaining a reasonable reactive power balance in the load centre by switching in shunt capacitors and shedding portions of the load if necessary. If installed and set correctly this system should prevent a major brown-out or black-out of large portions of a power system, as has been the case in many large power system disturbances throughout the world