Verification of High Voltage Divider with 10 · 10−6 Uncertainty

A transformer loss measurement (TLM) system calibration setup consists of three main components, a voltage divider (VD), current transformer and a power meter. The phase errors of the individual components of the reference setup for TLM system calibration should not be more than 10 µrad to achieve an overall system uncertainty of better than 20 µW/VA. We have verified the uncertainty level of the developed VD both from the component level and as a whole. Different practical conditions relevant for on-site measurements are considered, e.g. measurement cable lengths, cable types and grounding. The results shows that uncertainties of less than 10 µV/V in ratio error and 10 µrad in phase displacement are achievable.