Investigation of the Current Conversion Error of Rogowski Coil in a Wide Temperature Range

Rogowski coils are widely used for converting high-ampere currents in electrical installations. Large number of manufacturers produce Rogowski coils in various form factors. The use of this type of converters is promising for relay protection of electric power systems equipment due to such advantages as linearity of conversion, absence of saturation and residual magnetization phenomena, high accuracy of high-ampere current conversion. The metrological characteristics of the Rogowski coil depend on various factors that do not affect traditional current converters (electromagnetic transformers). One of these factors is the ambient temperature. The impact of ambient temperature can lead to an irreversible change in the size of coil turn and a corresponding change in the measurement error. In addition, commercially available Rogowski coils have a temperature coefficient of error of the conversion ratio from 0.005 to 0.02%/°C according to datasheets. Non-traditional current converters do not have sufficient experience in the conditions of electric power facilities operating in comparison with electromagnetic transformers. A comprehensive study of the characteristics of Rogowski coils is needed before their large-scale application for current measurement in electric power systems. This article is devoted to the study of the conversion errors of Rogowski coils in a wide temperature range corresponding to a moderately cold climate.