An economic and technical evaluation of condition monitoring for new SF6 circuit breakers

On-line condition monitoring systems for EHV SF6 circuit breakers are now commercially available from a number of manufacturers. They differ in a variety of ways, from the type of sensors used to the overall development of the system. Apart from examining the factors that influence the economic appraisal of on-line condition monitoring, the paper shows that the design and application of these systems must be considered carefully in order to minimise the effect on the reliability of the circuit breaker. The paper concludes with a discussion on the challenging issues that require further research in order to realise the full potential of condition monitoring.