Determination of Long-Term Voltage Stability of High Voltage Divider Having Bandgap Voltage References

The reference HVDC voltage divider constructed in 2012 is not a conventional voltage divider made up of resistive elements but has shunt type voltage references in its structure. The components in the uncertainty calculations are based on the temperature coefficient of the voltage reference, the current dependence of the measurement system, the leakage current and the corona effect, the short term stability caused by the thermal dependence and the DC voltage measurement uncertainty components. The uncertainty calculation has been done without long term stability effect since there is no data for the long-term deviation of the voltage divider. The measurement uncertainty was calculated to be 5 μV/V without considering this effect. According to the IEC 60060-2, the long-term stability of measurement systems has a direct impact on the measurement uncertainty. For this reason, the deviation of the reference measurement system is examined in the period between 2012 and 2017 and it is ensured that the uncertainty calculations include this effect. In this study, the long-term stability of a 20 kV reference DC high voltage measurement system based on the shunt type voltage references in its structure was analyzed and uncertainty were recalculated considering this effect