Accuracy Type Test for Rogowski Coils Subjected to Distorted Signals, Temperature, Humidity, and Position Variations

Abstract

Low-Power Instrument Transformers (LPITs) are becoming the first choice for distributed measurement systems for medium voltage networks. However, there are still a lot of challenges related to their operation. Such challenges include their accuracy variation when several influence quantities are acting on them. Among the most significant influence quantities are temperature, electromagnetic field, humidity, etc. Another aspect that increases the importance of studying the LPITs’ accuracy behavior is that, once installed, they cannot be calibrated for several years; hence, one cannot compensate for in-field conditions. Hence, this work aims at introducing a simple type test for a specific LPIT, the Rogowski coil. First, an experimental setup to assess the effect of temperature, humidity, and positioning on the power quality accuracy performance of the Rogowski coil is described. Second, from the results and the experience of the authors it has been possible to design a specific type test. The test has the aim of finding the limits of the accuracy variations of a single Rogowski coil. Afterwards, such limits can be used to compensate for the in-field measurements, obtaining an overall higher accuracy. The results of this work may contribute to the always-evolving standardization work on LPITs.

Testing Rogowski Coil with Digital Output for Smart Grid

“…The performance of LPCT under the effect of one of the typical influence factors differs from that under the influence of other factors. Calibration becomes more difficult when the LPCT is under the influence of more than one influencing factor simultaneously [21].…”

Testing Rogowski Coils with Merging Units for Smart Grids

“…The LPCT performance can vary under the influence of different typical factors. Calibration becomes more challenging when the LPCT is subject to the simultaneous influence of multiple factors [10].…”

“…Various calibration methods for RCs are available and can be found in the listed references. For instance, in reference [10], calibration for RCs is carried out to assess the influence of temperature, humidity, and positioning on power quality accuracy, but these calibration methods are primarily designed for RCs with analogue output.…”

The Accuracy of Evaluation of the Requirements of the Standards IEC 61000-3-2(12) with the Application of the Wideband Current Transducer

“…However, their metrological properties can be affected by the self-generation phenomenon caused by the non-linearity of the magnetization characteristic of the magnetic core [ 11 ]. This behavior is not observed with electronically controlled current transformers [ 12 , 13 , 14 , 15 , 16 ].…”