Date of Award

Spring 5-2023

Document Type


Degree Name

Master of Science (MS)


Electrical Engineering

First Advisor

Prashanna Bhattarai


This thesis presents the design and analysis of a digital model of an incremental-quantity-based directional protective relay element using the electromagnetic transient program (EMTP). The digital model is based on a similar protective element present in commercially available time-domain-based relays and provides directional fault detection using incremental quantities. Such models are not readily available in transient study programs.

The element’s operating principles are discussed in detail, and the digital design process is outlined. The digital model is designed in a simplified test system, and upon validation using a real-world time-domain-based relay, its performance is analyzed using the model of a real power transmission network. An automation script is developed to perform more robust testing. The development of the automation script is also discussed in detail within this thesis.

The digital model is intended to predict the performance of the same element in commercially available time-domain relays. Model performance was compared with a commercially available relay and the results were found to be similar.