Development of Measurement Systems for Water Content in Transformer Insulating Oil

Transformers are crucial devices for adjusting voltage levels to meet everyday requirements. However, transformers that operate continuously over extended periods are susceptible to significant failures and damage. A key factor contributing to these issues is the deterioration of insulation, often caused by contaminants in the insulating oil, with water being a primary culprit. The presence of water compromises the dielectric properties of the oil, leading to dielectric breakdown and potential transformer damage. One effective method for detecting water content in the oil is through the use of a capacitive sensor. This sensor functions by detecting changes in electrical charge that occur due to variations in the distance, cross-sectional area, and volume of the dielectric material. The sensor’s output is a capacitance value, which is then converted to a voltage reading. Experimental results have demonstrated that the MK33-W capacitive sensor is highly sensitive in measuring water content in transformer oil. The findings show an inverse relationship between capacitance and voltage, where an increase in capacitance corresponds to a decrease in measured voltage. The developed system performs reliably, with the humidity sensor exhibiting an error margin of 2.43% and the temperature sensor achieving an accuracy of 99.8%.