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

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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.

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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
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