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MONITORING OF SHORT INTERRUPTIONS

As short interruptions are due to automatic switching actions, their recording requires automatic monitoring equipment. Unlike long interruptions, a short interruption can occur without anybody noticing it. That is one of the reasons why utilities do not yet collect and publish data on short interruptions on a routine basis. One of the problems in collecting this data on a routine basis is that some kind of monitoring equipment needs to be installed on all feeders. A number of surveys have been performed to obtain statistical information about voltage magnitude variations and events. With those surveys, monitors were installed at a number of nodes spread through the system. As with long interruptions, interruption frequency and duration of interruption are normally presented as the outcome of the survey. Again like with long interruptions much more data analysis is possible, e.g, interruption frequency versus time of day or time of year, distributions for the time between events, variation among customers.

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