Water Quantity-Based Quality Measurement of Transformer Oil Using Polymer Optical Fiber as Sensor

Measurement of transformer oil quality plays an important role in health condition monitoring of a transformer. The breakdown voltage of transformer oil is influenced by both water content and temperature variation. Therefore, accurate assessment of water content in transformer oil and variation of breakdown voltage due to change in temperature are essential for health condition monitoring of a transformer. It helps to estimate the life expectancy of a transformer. This paper presents a polymer optical fiber sensor based instrumentation system (POFSBIS) to measure the water content in transformer oil of a transformer. Furthermore, the POFSBIS is also used to detect the effect of transformer oil breakdown under controlled laboratory environment. Ultraviolet visual spectrophotometer has been employed to study the changing temperature effect and voltage breakdown effect on transformer oil. The instrumentation system measures the water content in transformer oil as well as provides the online information about the breakdown occurrence in transformer oil which helps to prevent the catastrophic losses of a transformer.