Analysis of operation of voltage transformers during interruptions and dips of primary voltage

Short transient states during interruptions and dips of the supply voltage of the voltage transformer are the cause of low power quality and source of impulsive conductive disturbances which are transferred to secondary side of the voltage transformer. Maximal values of these impulses are able to exceed even several times rated rms values of primary and secondary voltages. This may lead to abnormal operation of measuring and protection apparatus connected to the secondary side of voltage transformer or even to their damage. In this article used methods of measurements for calculation of the factor of transfer of impulsive disturbances from primary to secondary sides of voltage transformer are presented as well as results of analysis of the influence of construction parameters of windings and their operation conditions on the amount and quality of this transfer.