Introduction

Abstract

There was a time when power systems, and in particular transmission systems could afford to be overdesigned. However, in the last two decades power systems have been operated under much more stressed conditions than was usual in the past. There is a number of factors responsible for this: environmental pressures on transmission expansion, increased electricity consumption in heavy load areas (where it is not feasible or economical to install new generating plants), new system loading patterns due to the opening up of the electricity market, etc. It seems as though the development brought about by the increased use of electricity is raising new barriers to power system expansion.

“Je n’ai fait celle-ci plus longue que parce que je n’ai pas eu le loisir de la faire plus courte”¹ Blaise Pascal