Present practices and trends on the French power system to prevent voltage collapse

The authors present the measures taken on the French power system to prevent voltage collapse. After a brief presentation of the voltage collapse experienced in 1987 in the western part of France, the different time scales, from planning to real-time operation, are examined. The planning methodology, role of generating sets, operating rules, tools, and means of action for real-time operation are discussed. Finally, future trends and research in the field of assessing system vulnerability and detecting critical states in real time are presented