Test instrument for the automatic compliance check of cast resin insulated windings for power transformers

In this paper a new instrument specifically designed for the compliance check of windings for Medium Voltage/Low Voltage (MV/LV) cast resin insulated power transformers is presented. The proposed instrument, based on the SFRA (Sweep Frequency Response Analysis) measuring technique, has been designed to carry out automatic measurements during the industrial production of the windings. In this paper the main hardware and software instrument features are presented, with particular consideration of the algorithm adopted for the compliance check. Finally, results obtained during both the lab instrument characterization and the on-field validation at the BTicino winding production factory is also presented.