Smart Characterization of Rogowski Coils by Using a Synthetized Signal

Costa

et al. 2022

Sensors

Self Cite

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.

Section: Importance Of Testingmentioning

confidence: 99%

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

Costa

et al. 2022

Sensors

Self Cite

“…Note, that studies on inductive VTs and CTs have been published for a few decades; hence, they can be considered a consolidated topic. As for the LPITs, different kinds of LPCTs and LPVTs were characterized in [ 17 , 19 , 20 ] and [ 14 ], respectively.…”

Section: Introductionmentioning

confidence: 99%

Simplified and Low-Cost Characterization of Medium-Voltage Low-Power Voltage Transformers in the Power Quality Frequency Range

Betti

et al. 2022

Sensors

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The distribution network is experiencing a massive deployment of intelligent electronic devices (IEDs) such as energy meters, protective devices, and phasor measurement units (PMUs). This phenomenon resulted, on the one hand, in (i) the availability of distributed measurement systems capable of monitoring and collecting measurements from the distribution network, and (ii) increasing awareness of the system operator about the status of the network. On the other hand, such a significant number of devices require to be characterized, over the years, and assessed in both sinusoidal and distorted conditions. However, the characterization process may require a huge investment of money and time considering the low availability of reference instruments and accredited laboratories. To this purpose, this paper presents a simple and fast test procedure, performed with cheap and low-voltage instrumentation, to characterize two off-the-shelf low-power medium-voltage sensors in the power quality frequency range. In detail, the paper describes the measurement setup developed for the characterization and the performed tests. In addition, the method was also reproduced with reference equipment for validation purposes. Lastly, for both tests, an uncertainty evaluation was performed to quantify the goodness of the proposed method. From the results, it is possible to appreciate that the designed cheap and simple test can achieve as accurate results as those of a sophisticated and expensive equipment.

“…Other studies, instead, focus on the modelling of such devices, as done by the authors in [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Combined Effect of Temperature and Humidity on Distorted Currents Measured by Rogowski Coils

Costa

2022 20th International Conference on Harmonics &Amp; Quality of Power (ICHQP)

et al. 2022

Self Cite

The necessity of accelerating towards carbon neutrality has been further pushed in recent times. Therefore, with the aim of developing smart grids, new Intelligent Electronic Devices (IEDs) are being widely installed. In this regard, Low Power Current Transformers (LPCTs) are replacing traditional inductive current transformers (CTs). Among these, Rogowski coils feature high linearity, reduced dimensions, and wide bandwidth in comparison to CTs. Hence, this work presents a study on a particular type of LPCT, the Rogowski coil, which is extensively used nowadays. In detail, temperature and humidity are simultaneously applied to three commercial Rogowski coils when measuring off-nominal, hence distorted, currents. The LPCTs performances are evaluated in terms of power quality indexes, Total Harmonic Distortion (THD) and single harmonic evaluation. From the results, THD is not significantly affected by the combined temperature/humidity presence. However, a deep analysis on the single harmonic demonstrated how they are strongly correlated to such influence quantities. It is interesting to highlight that each of the three devices under test present different behaviors. It is then crucial to in deep the investigation on the influence quantities affecting LPCTs. Furthermore, International Standards should include new details and test procedures to assess the effect on the LPCTs accuracy due to such quantities.