Corona tests on reduced-scale two-conductor hybrid lines

Tests were conducted to determine the effect of various parameters on DC fields due to the interaction between energized AC and DC conductors. A summary of observations and conclusions drawn from over 25,000 readings taken in the course of more than 40 series of tests is given. Quantities measured were the ground level DC electric field strength and ion current density, and conductor corona currents. Parameters were the hybrid line geometry, the conductor conditions, the magnitude of the applied AC and DC voltages, and the polarity of the applied DC voltage