Improved transformer temperature monitoring

This article discusses transformer temperature monitoring where a strategy of reduction in maintenance costs and outages, by replacing older ancillary technology with modern IEDs, can offer a reduction in maintenance costs, while providing an increase in availability and reliability. Winding temperature indicators are critical devices on a transformer as they not only control the cooling system, but also provide the transformer with thermal protection. Utility experience indicates that a significant part of transformer maintenance is devoted to winding temperature indicators. With the advent of on-line monitoring, the preferred transformer temperature monitoring solution is to use fully electronic devices, which continuously calculate the winding hottest temperature based on the measured values of top oil temperature and load current measurements