Adapted Technique for Calibrating Voltage Dividers of AC High-Voltage Measuring Systems

This paper presents an adapted technique to calibrate the AC voltage divider of AC high-voltage measuring systems up to 200 kV at the Egyptian National Institute of Standards. Two identical capacitors have been used as two similar AC high-voltage capacitive dividers. Firstly, the dividing ratios of two capacitors have been achieved by calibrating each capacitor via a traceable reference standard AC high-voltage divider up to 100 kV. Then, both capacitors have been connected in series to perform as one 200-kV AC voltage divider. They have been calibrated via the same 100-kV reference standard divider to experimentally get their actual dividing ratios up to 100 kV. In order to get their dividing ratios from 100 to 200 kV, a mathematical derivation has been determined. The concept of this derivation is when applying the doubled voltage to two identical pre-calibrated voltage dividers connected in series, their input voltage is almost equally divided across these two dividers. Finally, these calibrated two series capacitors have been used to calibrate a voltage divider of a 200-kV AC HV measuring system. The uncertainty contributions for all the results have been estimated. Enhanced uncertainties have been acquired using this proposed adapted calibration technique.