USING THE NUMERICAL PROTECTIONS FOR MEDIUM VOLTAGE POWER LINES GROUNDED WITH PETERSEN COIL

Autor/autori: Prof. Gheorghe Hazi, PhD, Prof. Aneta Hazi, PhD, Sorin Vernica, PhD

Rezumat: In lucrarea de fata autorii analizeaza conditiile de functionare selectiva a protectiilor numerice in cazul liniilor electrice de medie tensiune cu neutral tratat prin bobina de stingere. Analiza se refera la protectia impotriva punerilor la pamant monofazate, aceste defecte ridicand problem de selectivitate in functionarea protectiilor. Concluziile se bazeaza pe determinarea prin calcul a curentilor de punere la pamant si a defazajelor dintre curentul homopolar si tensiunea homopolara. Se prezinta rezultatele obtinute pentru linii de 20 kv aeriene si in cablu.

Cuvinte cheie: punere la pamant, protectie homopolara directionata, bobina de stingere

Abstract: In this paper the authors analyze the selective operating conditions of the numerical protections in case of medium voltage power lines grounded with Petersen coil. The analysis refers to the protection against one-phase grounded, these faults raising the issue of selectivity in the operation of protections. Conclusions are based on the determination by calculation of the earth fault currents and the phase shifts between zero sequence current and zero sequence voltage. It presents the results obtained for 20 kV overhead lines and cable lines

Keywords: earth fault, earth fault protection, Petersen coil

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