Measuring transmission-line impulse voltages

THREE companion papers describe impulse tests performed on the experimental transmission lines of the American Gas and Electric Company.^1–3 When these tests were being planned, it was necessary to select voltage dividers capable of reducing the high-surge voltages to a level suitable for measurement by a cathode-ray oscillograph. Selecting dividers for measuring transmission-line surges is complicated by the necessity of obtaining a high divider impedance to prevent excessive reflections on the line while maintaining an acceptable divider response.