Determination of Corona Inception Voltages of Rod-Plane Electrode Systems

This paper presents experimental and numerical evaluations of corona inception voltages for rod-plane electrode systems. Brass electrodes with hemispherical terminals were used as rod electrodes. The radius of the hemispherical design was 1 cm and the total lengths of the rod electrodes were 100 cm. The plane electrode was made of aluminum material, and it had 1 m x 1.4 m dimensions with 0.6 cm thickness. The corona onset voltages of the electrode systems were determined up to 100 cm electrode spacings with 10 cm intervals under AC, (+) DC and (-) DC voltages. Ambient temperature of the test room was kept constant whereas humidity was changed to determine the humidity effects on the corona onset voltages. In addition to the experimental work, numerical studies were performed using Finite Element Method, and maximum electric field strengths corresponding to the corona onset voltages were determined.