Measuring installation for the research of errors of measuring current transformers in the extended frequency range 40–2500 Hz

Abstract

The use of measuring current transformers for the analysis of electrical energy quality indicators requires normalization of their metrological characteristics in the frequency range of 40–2500 Hz, the upper limit of the range corresponds to the value of the 50th harmonic at the frequency of the industrial network of 50 Hz. The metrological support for determining the characteristics of measuring current transformers at the frequency of the industrial network is considered and it is shown that it is necessary to expand the frequency range used, as well as to be able to assess the influence of the harmonic composition of the measured sinusoidal current on the metrological characteristics of these devices. As a result of the work performed, a measuring installation was created to study the metrological characteristics of measuring current transformers in the extended frequency range of 40–2500 Hz. Possible methods of studying the characteristics of measuring current transformers are described and a differential-zero measurement method is selected. A study of the measuring installation was carried out and its characteristics were obtained – the range of reproducible frequencies; the range of reproducible current in the measuring circuit in a given frequency range from 40 to 2500 Hz; uncertainties in the transmission of units of the coefficient and the angle of the scale conversion of the sinusoidal current to measuring current transformers. The results are relevant for assessing the metrological characteristics of current converters used in power engineering and industry, and for the development of metrological support for measuring current transformers in the extended frequency range.