Visible to the public Factors influencing CT saturation and its implications on Distance Protection Scheme-Analysis and Testing

TitleFactors influencing CT saturation and its implications on Distance Protection Scheme-Analysis and Testing
Publication TypeConference Paper
Year of Publication2021
AuthorsKuber, Sughosh, Sharma, Mohit, Gonzalez, Abel
Conference Name2021 74th Conference for Protective Relay Engineers (CPRE)
KeywordsCircuit faults, compositionality, current transformers, cyber physical systems, Fault currents, Internet of Things, Magnetic flux, Protective relaying, pubcrawl, Reliability engineering, remanence, Resiliency, Transient analysis
AbstractThe behavior of the Current Transformer (CTs) is of utmost importance for protection engineers to ensure reliable operation of power system. CT magnetic saturation is a well-known phenomenon when analyzing its performance characteristics. Nevertheless, transient conditions in the system might be different every time. A good understanding of the magnetic saturation of different CT designs and the effect of saturation on the protection schemes is imperative for developing a robust and dependable protection system. In this paper, various factors that affect CT saturation like X/R ratio, large current magnitudes, DC offset, burden and magnetization remanence are discussed. Analysis of CT saturation based on changes to burden and remanence is performed. In addition to that, the effect of saturation due to these factors on distance protection are presented with test results and analysis. Saturation conditions are analyzed on mho distance elements during phase to ground and three phase faults. Finally, a practical approach to efficiently test the performance of protection schemes under CT saturation conditions is proposed using COMTRADE play back. COMTRADE play back files for various scenarios of CT saturation conditions are generated and used for testing the performance of the protection scheme.
DOI10.1109/CPRE48231.2021.9429851
Citation Keykuber_factors_2021