Operational measures to alleviate the possibilities of supply failure

Most electric utilities expend considerable time and effort, on a daily basis, in ensuring correct operational planning to ensure that their transmission system does not get into the region where automatic or manual defence plans are required. While such defence plans generally exist, considerably less time is expended on them. Black start plans are a necessary requirement as there must be a method of restarting the system if complete failure has taken place. It is interesting to attempt some analysis on whether the time spent on each subject is correctly allocated. Consideration has been given to the average amount of time each year spent in normal and other modes of operation, and into the energy lost due to failures of supply in each of these modes of operation. The product of these two quantities may be considered as a measure of the time that ought to be spent on activities concerned with each of the modes of operation