Analysis on the Transfer Characteristics of Rogowski-coil Current Transformer and Its Influence on Protective Relaying

Yi Wang, Jiaman Li, Yulan Hu, Ranran An, Zexiang Cai, Ruiwen He

Electric Power Research Institute, Guangdong Power Grid Corporation, Guangzhou, China.
School of Automation, Guangdong University of Technology, Guangzhou, China.
School of Electric Power, South China University of Technology, Guangzhou, China.

DOI: 10.4236/epe.2013.54B251                

Abstract

This paper systematically analyzes the transfer characteristics of the Rogowski-coil Current Transformer and its effect on protective relaying through theoretical analysis, experiments and simulations. The frequency characteristics and transient characteristics of Rogowski transducer and Rogowski-coil Current Transformer are deeply analyzed based on the physical structure of the transformer. It is revealed that broad bandwidth of the transformer can improve the performance of protective relaying, and the bandwidth is determined mainly by the parameters of the Rogowski transducer and signal processing circuits. It is also discovered that the measurement errors of transient current mainly depend on the abilities for the current transformer to reproduce an accurate replica of the decaying dc components, which is mainly decided by the decay time constant of the aperiodic component of transient current and the parameters of the integral unit. Finally, some measures are proposed for the performance improvement of Rogowski-coil Current Transformer to meet the requirements of protective relaying system in terms of structural design and testing standards.

Keywords

Current Transformer; Rogowski-coil; Transfer Characteristics; Protective Relaying

Conflicts of Interest

The authors declare no conflicts of interest.

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