Design loading resistance of current transformers of high-power unit in the mode of ground short circuit

• Main Authors: Zhuravlev, P.E., Glazyrin, V.E.
• Format: Conference Proceeding
• Language: English
• Subjects: Circuits; Current supplies; Current transformers; Power generation; Power supplies; Power systems; Protection; Protective relaying; Voltage fluctuations; Wire
• DOI: 10.1109/IFOST.2007.4798604

This paper presents the current transformer loading resistance design in the mode of ground short circuit. Design loading resistance of YCTG at high-voltage side of the unit substantially depend prefault unit conditions. At F (1) by rated prefault duty when Z cal of current transformers is maximal - indelivery of actual power to power system operating in the maximal mode that provides the maximal current of zero sequence value. In the mode of ground short circuit near the high-power generator-transformer unit operating in the power system is necessary for using as one of rated duty when definition of loading resistance of current transformers in YCTG at high-voltage side. Because design loading in such mode can essentially exceed loading at the same kinds of short circuit but in a mode of isolated unit operate. Design model of primary connections of power plant for loading definition of current transformers in YCTG at high-voltage side of the unit usually not to agree with the maximal power plant mode by calculation of short circuit currents.