Voltage collapse: case studies

This paper presents an analytical approach for the identification of optimal locations and sizes of reactive power compensation required to improve power system voltage stability. The paper also describes reactive compensation planning necessary to avoid a power system collapse similar to that which occurred in Australia´s Hydro-Electric Corporation (HEC) power system. This incident, caused initially by a bus fault and followed by a multiple contingency outage condition, resulted in the loss of about two thirds of the power system load for a period of about two hours