Zero Sequence Filtering in Differential Protection

Zero sequence filtering is a concept used to eliminate zero sequence current component from the secondary current of Current Transformer used in Differential Protection of Transformer. This concept is useful in Transformer having earthed Star winding. What is the Need for Zero Sequence Filtering? Let us have a detailed discussion on this topic. For better … Read more

Harmonic Restraining in Differential Protection

In this post we will discuss about the feature of Harmonic Restraining feature of Differential Protection. First we should know why Harmonic Restraining is needed? Suppose we are going to energize the Transformer, obviously the Transformer will have an Inrush current which is around 6 times of full load current. Refer “Transformer Inrush Current” for … Read more

Transformer Differential Protection

What is Differential Protection? Differential Protection is based on the fact that any fault within electrical equipment will result into the difference in current entering it and the current leaving it. Thus by comparing the two currents either in magnitude or in phase or both we can determine a fault and issue a trip decision … Read more