CASPIAN JOURNAL
MANAGEMENT AND HIGH TECHNOLOGIES
Modern instrument transformers
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Read | Urakseev Marat A., Khoteev Aleksey L. Modern instrument transformers // Caspian journal : management and high technologies. — 2012. — №3. — pp. 41-48. |
Urakseev Marat A. - D.Sc. (Engineering), Ufa State Academy of Economics and Service, 145 Chernyshevsky st., Ufa, 450078, Russia,, alexleohot@mail.ru.
Khoteev Aleksey L. - post-graduate student, Ufa State Academy of Economics and Service, 145 Chernyshevsky st., Ufa, 450078, Russia,, alexleohot@mail.ru.
Instrument current and voltage transformers of high voltage transmission lines, based on electromagnetic principles, have drawbacks: phenomena of saturation, hysteresis, resonance, residual magnetization. The consequence of these shortcomings is to increase the measurement errors. The studies of other physical principles allowed to form measuring devices devoid of shortcomings of instrument transformers of the previous generation. In modern instrument current transformers magneto-optical Faraday effect is used, and in voltage transformers linear electro-optical Pockels effect is used. In both cases, voltage or current measurement is reduced to the measurement of light intensity at the output of analyser. Using fibre-optic cable measuring equipment can be placed at a considerable distance from primary transducers and transmission line, which introduces the error in measurements by strong electromagnetic fields. Patents of foreign companies reveal the essence of voltage transformers based on electro-chemical elements. The economic effect of the use of voltage transformers with electro-optical Pockels cell as compared with electromagnetic instrument transformers is achieved by eliminating risk of fire or explosion of primary voltage transducer as well as costs of copper winding. Appropriateness of using optical instrument transformers is confirmed by the favorable experience of their exploitation in the United States and Canada.
Key words: Instrument transformers,Electro-optics,High-voltage transmission lines,Linear electro-optical effect,Intensity of light flux,Birefringence,Pockels cell,Plane-polarized beam