On the prediction of current-voltage characteristics for positive wire-to cylinder corona discharge

The current-voltage curves in wire-to-cylinder arrangement are investigated for positive corona discharge varying the electrode gap and the emitter radius. Two well-known expressions are used to relate the corona current as a function of the voltage. Then, the dependencies of the equation parameters on geometrical characteristics of the electrodes are studied. The main results are as follows: 1) the dimensional parameter K shows a directly dependence with the emitter radius whereas an inversely dependence is observed with electrode distance; 2) the inception voltage Vo increases with both emitter radius and electrode gap; 3) the exponent m varies inversely with emitter radius and it is proportional to the electrode gap. Based on the experimental results, a derived empirical formula for positive corona current discharge is proposed as a function of the applied voltage and the geometrical characteristics of the electrodes. Finally, the empirical equation is examined with data of previous studies to assess its validity.