Abstract:
Background Distribution transformers in the high altitude electromagnetic pulse (HEMP) conduction environment are subjected to nanosecond electrical stress, which can easily cause insulation failure or damage between the winding leads.
Purpose This paper takes the transformer winding model as the basis to study the relationship between the volt-second characteristics of oil-immersed paper, breakdown probability, pulse voltage amplitude, and cumulative number of withstand times with different half-height widths and rising edge of the nanosecond voltage pulses (U-N characteristics) .
Methods Modify the circuit components to alter the output voltage’s half-width and rise time, thereby investigating the impact of these changes on the breakdown characteristics of oil-immersed paper. Apply the Weibull distribution function to fit and analyze the resulting data.
Result When the fixed rising edge is 20 ns, the breakdown voltage decreases as the half-height width increases; when the fixed half-height width is 500 ns, the breakdown voltage increases as the rising edge increases.
Conclusions The effects of different voltage parameters on the volt-second characteristics and breakdown probability are more obvious, and it is found that the probability of breakdown of oil immersed paper wave head decreases with the increase of full width at half maximum, and increases with the increase of rising edge, resulting in changes in breakdown probability and volt-second characteristics. The change in U-N characteristics is more affected by the magnitude of voltage amplitude, and less affected by changes in voltage characteristic parameters.
下载: