Steep Front Short Duration Low Voltage Impulse Performance of Distribution Transformers

An extensive literature search [1] of steep front short duration (SFSD) impulse sources, their characteristics and effect on power system equipment has led to the specification of a test program [2] to evaluate key apparatus and insulations. Distribution transformers, although not overly susceptible to impulse damage, have been selected as one of the candidate apparatus for low and high voltage SFSD impulse tests. This paper covers the low voltage SFSD impulse response of conventional oil insulated shell form and core form distribution transformers. This research work is sponsored in part by the Office of Energy Storage and Distribution of the Department of Energy (DOE).