Русская версия English version

Analysis of frequency-dependent characteristics of digital current and voltage transformer current sensors

V.D. Lebedev, D.G. Grigoriev

Vestnik IGEU, 2024 issue 3, pp. 29—38

Download PDF

Abstract in English: 

Background. Digital measuring current and voltage transformers (DCVT), which incorporate various current and voltage sensors are the key sources of information about processes at modern digital substations. Classic small-sized current transformers, Rogowski coils, magnetotransistor sensors, Hall effect sensors, fiber-optic Faraday effect sensors, as well as shunts can be used as current sensors in DCVTs. For redundancy purposes, current channels are performed in several copies and on different sensors. Sensors that are different in nature have their own set of advantages, which together makes it possible to obtain the effect of eliminating the shortcomings of specific sensors. For example, they may not have a saturation effect or transmit the direct current component quite accurately, which is a significant advantage over classic current transformers. At the mains frequency, the behavior of these sensors is predictable, but their behavior is not well studied at higher and lower frequencies. Thus, it is decided to study the frequency response and phase response of these sensors in a wide frequency range.

Materials and methods. To solve the problems within the framework of this study, physical experiment, analytical and empirical solution methods have been used.

Results. As a result of the study, the frequency response and phase response of current sensors of DCVT in a wide frequency range have been obtained. Analog filter has been designed to correct the signal of the magnetotransistor sensor.

Conclusions. The results obtained coincide with theoretical data and can be considered when developing digital relay protection and automation algorithms.

References in English: 

1. Draxler, K., Styblikova, R. Using instrument transformers in a wider frequency range. 2011 IEEE International Instrumentation and Measurement Technology Conference. Hangzhou, China, 2011, pp. 1–4. DOI: 10.1109/IMTC.2011.5944298.

2. Cataliotti, A., Di Cara, D., Di Franco, P.A., Emanuel, A.E., Nuccio, S. Frequency response of Measurement Current Transformers. 2008 IEEE Instrumentation and Measurement Technology Conference. Victoria, BC, Canada, 2008, pp. 1254–1258. DOI: 10.1109/IMTC.2008.4547234.

3.  Plakidin, R.S., Ul'yanov, D.N., Khromtsov, E.I., Andreev, P.I., Mokeev, A.V. Voprosy primeneniya tsifrovykh transformatorov toka na osnove katushki Rogovskogo dlya TsPS [Issues of using digital current transformers based on Rogowski coils for digital substations]. Mezhdunarodnaya nauchno-tekhnicheskaya konferentsiya «Releynaya zashchita i avtomatika energosistem – 2023» [International scientific and technical conference “Relay protection and automation of power systems – 2023”]. Sochi, 2023. Available at: https://enip2.ru/Publication/rza_23_es_6.3_1_RRC_06_plakidin.pdf (accessed 18.04.2024)

4.  Chen, Y., Huang, Q., Jing, S., Mo, C., Zhen, W., Wu, J. Development of the test platform for the characteristics of the Rogowski coil electronic current transformer. 2016 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE). Chengdu, China, 2016, pp. 278–283. DOI: 10.1109/ICSGCE.2016.7876069.

5.  Ji, J., Yuan, Y., Pang, F., Zheng, Y. Investigation on anti-interference of Rogowski coil current transformers in smart substations. 2017 IEEE Conference on Energy Internet and Energy System Integration (EI2). Beijing, China, 2017, pp. 1–6. DOI: 10.1109/EI2.2017.8245234.

6.  Grechukhin, V.N. Elektronnye transfor-matory toka i napryazheniya. Sostoyanie, perspektivy razvitiya i vnedreniya na ORU 110–750 kV stantsiy i podstantsiy energosistem [Electronic current and voltage transformers. Status, prospects for development and implementation at outdoor switchgear 110–750 kV stations and substations of power systems]. Vestnik IGEU, 2006, issue 4, pp. 35–42.

7. Hrabcik, M., Javora, R., Prokop, V. Low-power Instrument Transformers Frequency Response and Accuracy Requirements for Harmonics. Proc. of the 25th International Conference on Electricity Distribution (CIRED 2019). Madrid, Spain, 2019. DOI: 10.34890/579.

8. Lebedev, V.D., Yablokov, A.A., Lebedev, D.A., Naumov, A.V., Mironov, S.V. Tsifrovoy transformator toka i napryazheniya [Digital current and voltage transformer]. Patent RF, no. 174411, 2017.

9.  Lebedev, V.D., Grigor'ev, D.G. Razrabotka i issledovanie podkhoda k obrabotke signalov tsifrovykh izmeritel'nykh transformatorov toka i napryazheniya [Development and research of an approach to signal processing of digital instrument current and voltage transformers]. Vestnik IGEU, 2024, issue 2, pp. 32–48. DOI: 10.17588/2072-2672.2024.2.032-048.

10.   Starodubtsev, Yu.N. Teoriya i raschet transformatorov maloy moshchnosti [Theory and calculation of small power transformers]. Moscow: IP RadioSoft, 2005. 320 p.

11. Khorovits, P., Khill, U. Iskusstvo skhemotekhniki: v 3 t., t. 1 [The Art of Electronics: in 3 vols., vol. 1]. Moscow: Mir, 1993. 413 p.

Key words in Russian: 
частотные характеристики, измерительные трансформаторы тока, цифровые трансформаторы тока
Key words in English: 
frequency characteristics, measuring current transformers, digital current transformers
The DOI index: 
10.17588/2072-2672.2024.3.029-038
Downloads count: 
6