On-line multi-sensor monitoring system for insulation condition of oil-immersed power transformer

An on-line monitoring and diagnostic system for a 220kV oil-immersed power transformer with 3 windings has been established in a substation of China. The operation monitoring and insulation condition evaluation were integrated into this system. Many sensors were applied to monitor multiple insulation items such as partial discharge, dissolved gas, moisture in oil, oil temperature, coil hot spot temperature, iron core current, bushing condition and so on. The structure of the system was introduced and a diagnostic flow, via information fusion technology, was presented. Based on the system, it is easy to obtain the operating condition and insulation condition of the transformer.