Detection of winding radial deformation in power transformers by confocal microwave imaging

In this article, a new bi-static method for the detection and determination of magnitude and location of winding radial deformation in power transformers has been proposed. In this method, which is based on confocal microwave imaging, a ultra-wideband transceiver is utilized to emit a short pulse toward the transformer winding and determine its reflection at several points along a linear path. The measured signals are then processed to obtain a 2D image of the winding. The effectiveness of this algorithm for radial deformation is demonstrated through four different experiments. The resultant image provides satisfactory information of the magnitude and position of the radial deformation in transformer.