Introduction

Abstract

The basic functions of our modern society are dependent on electricity supply. Lighting, water supply, heating, traffic and fuel supply, food storage and delivery, payment transactions, telecommunication, and information systems are heavily affected by interruptions. Therefore, the electricity system can be regarded today as the most important infrastructure.

The introduction of electricity markets has brought economic aspects and cost awareness more in focus. The importance of the power system and the requirement to be effective have forced the system operators to analyze more in detail the benefits and costs of investments and maintenance in the power system. Furthermore, the effects of unreliable electricity supply on modern society have been under consideration. The method presented in this book is an approach to treat the security systematically using an established reliability method, probabilistic safety analysis, PSA. The method suits best for the power systems where the dynamic behaviour after faults plays a role and the stability has to be considered.