Research on Application of Distributed Optical Fiber Sensing in Monitoring of Temperature and Winding Deformation of Large Transformer

In order to realize the distributed monitoring of the temperature and strain information of the full length of the transformer windings, a 110kV transformer was modified, and sensing fibers were arranged on its low-voltage winding and medium-voltage winding. The paper-wrapped optical fiber arrangements suitable for different types of windings could be used inside transformers, and their application range could be extended to the intelligent alteration of newly produced transformers and returned transformers. The lead-out method and wiring method of the sensor fiber inside the transformer were also explored. The modified transformer was verified by routine tests and type tests to meet the factory standards. Using BOTDR, BOTDA, ROTDR and other distributed optical fiber sensing methods, the real-time monitoring of winding temperature during the temperature rise test and the monitoring of winding deformation before and after the short circuit test can be realized. The data processing method of transformer condition monitoring based on distributed optical fiber sensing technology was explored, and the winding temperature field distribution during the operation and the strain field distribution after short-circuit impact were both obtained. © 2022 Chin.Soc.for Elec.Eng.