Voltage surges transferred to the secondary of distribution transformers

This paper presents a simplified model of power distribution transformers that enables the investigation of some characteristics of the voltage surges transferred to the low-voltage terminals in case of a lightning discharge in the vicinity of an overhead line. Good agreement is found on comparisons between measured and calculated transferred voltages when an 1.2×50 μs impulse voltage is applied to the HV terminals. Making use of the model, some typical situations are simulated and the transferred voltages are calculated considering four distribution transformers commonly used in Brazil