Research of on-line monitoring of moisture content in transformer oil

The moisture distribution in the transformer and variation mechanism of moisture in oil is analyzed in this paper, and using relative saturation and temperature as characteristic parameters, a detail scheme of online moisture content monitoring in transformer oil is put forward. The polyimide-based capacitive humidity sensor and temperature sensor are employed in online monitoring moisture content in oil. Computer is utilized to sample and analyze the data from sensors. The experiment on test transformer confirms that the sensors can work reliably, and accurately reflect the moisture content in transformer oil. The proposed method can realize the purpose of on-line monitoring.