Downloads: 1 | Views: 13
Research Paper | Electrical Power Engineering | India | Volume 10 Issue 7, July 2021
Accurate Method of Excitation Current and Relay Current Prediction during an Offset Fault at the Terminals of Power Transformer and Derivation of Saturated Relay Current
PV Subramanian | Ajitha Lekalappudi | Nupur Gayathri
Abstract: This article describes a method of accurately predicting CT excitation current and relay current from first principles during a terminal fault of a power transformer including AC and DC components which are required for over design values of CT flux as well as the knee point values of the CT depending on the relay applications desired. It is known that the CT secondary current is an accurate replica of the primary fault current but the relay current depends on the CT excitation current drawn. In case the relay current is to be analytically predicted the excitation current also has to be predicted accurately whose value has to be subtracted from the total secondary current. This excitation current depends on the CT saturation level and can form a considerable portion of the CT secondary current depending on the CT saturation level. Therefore an accurate method of analysis of CT excitation and relay currents becomes important. This article recommends a method of accurately deriving the excitation and relay current from first principles as a function of time taking into account both the AC and DC components for purposes of CT design and relay applications.
Keywords: Power Transformer, Excitation current, Relay current, CT saturation, CT Over design factor, Offset fault Current
Edition: Volume 10 Issue 7, July 2021,
Pages: 532 - 538
Similar Articles with Keyword 'Power'
Research Paper, Electrical Power Engineering, Iraq, Volume 10 Issue 12, December 2021Pages: 1310 - 1313
Performance Evaluation and Simulation of ON-GRID PV Plant in Baghdad-Iraq
Mohammed Adnan Hameed | Dr. Qais Matti Alias | Abeer Salman Obeid
Research Paper, Electrical Power Engineering, Algeria, Volume 11 Issue 7, July 2022Pages: 214 - 225
Evaluation of Electricity Excess in Hybrid Energy System
ADDA M'hamed | ALHAMRANI Ramadan | BENHAMOU Amina | BERKOUK El Madjid