Leakage Current Effect of a Supporting Insulator on the Performance of a Resistive High-voltage

A new method is presented for measuring the insulation resistance of a Teflon insulator in a resistive high-voltage divider, which is difficult when using the bridge or voltmeter methods. Our method determines the insulation resistance from the difference in the voltage dividing ratio before and after connecting calibrated high-ohm resistors to the Teflon insulator in parallel. As the measurement results performed using this method, it is shown that the Teflon’s insulation resistance, a support of a national dc high-voltage divider, is 5 × 1014 to 2 × 1015 Ω. This means that the leakage resistance effect on the voltage dividing ratio was less than 0.4 × 10−6, representing an insignificant impact on the divider’s performance.