Research of the State Primary Standard of the unit of scaling factor of AC voltage up to 750/√3 kV

All electrical energy is produced, transmitted and distributed at high voltages. In this case, the measurement of the amount of electricity is carried out by electricity meters together with voltage transformers (VTs). The largest capacities are transmitted and distributed on power transmission lines of voltage of class 750 kV. In Ukraine there are about two hundred measuring VTs of class 750 kV. In addition, power facilities have been actively built recently, which will also require the installation of 750 kV transformers. Working VTs of substations for a class of 750 kV may have great weight and dimensions. Their height is 7 m and weight is 4000 kg. Working measurement standards have the same weight and dimensions. Therefore, obtaining the size of a physical quantity from the measurement standards of other countries is very difficult for two reasons: it is very difficult to transport such working measurement standards abroad; only a few countries have measuring instruments with a voltage of 750 kV. The purpose of the article is to highlight the results of researches of the State Primary Standard of the unit of scaling factor of alternating current (AC) voltage up to 750/√3 kV, in particular: formation of the composition of a set of measuring instruments for the reproduction of the unit of scaling factor; establishing a method for reproducing the unit of scaling factor; estimation of uncertainty of measurements and other metrological characteristics while transferring the unit of scaling factor. The article presents the results of the research of the newly established State Primary Standard of the unit of scaling factor of AC voltage up to 750/√3 kV, which are of great practical importance. Those researches are aimed at improving the metrological traceability of AC high-voltage at the national level. Keywords: AC high-voltage; measurement standard; measurement; calibration; uncertainty of measurement.