Improving sensitivity of residual current transformers to high frequency earth fault currents

• Main Authors: Czapp Stanislaw, Dobrzynski Krzysztof, Klucznik Jacek, Lubosny Zbigniew, Kowalak Robert
• Format: Article
• Language: English
• Published: Polish Academy of Sciences 2017-09-01
• Series: Archives of Electrical Engineering
• Subjects: current transformers; earth fault currents; electric devices; electromagnetic couplings; high frequency
• Online Access: http://www.degruyter.com/view/j/aee.2017.66.issue-3/aee-2017-0036/aee-2017-0036.xml?format=INT
• ISSN: 2300-2506

For protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed the modification in the structure of residual current devices. This modification improves sensitivity of residual current devices when high frequency earth fault current occurs. The test of the modified residual current device proved that the authors’ proposition is appropriate.