Quality Assessment of Power Transformers Differential Protection Behavior Using Harmonic Restraint Techniques

Abstract

This paper assesses the implementation of harmonic restraint and harmonic blocking and highlights how these techniques are performed in transformer differential protection modern relays, including how these techniques affect the speed and safety of transformer differential protection. Moreover, the paper highlights the wide range of the percentage values of the harmonics in the magnetization current. The harmonics resulting from both a simulation and practical measurements in the field will be analysed.