Distance protection functional testing for a 33kv traction network using hardware in the loop real-time simulation

Abstract

The thesis focuses on designing a distance protection scheme for a medium-voltage system (33kV). Transmission and distribution lines form a critical part of the power system infrastructure. The reliability and high performance of these lines are essential for the efficient transmission of electrical power. To ensure the integrity of the infrastructure, power system protection schemes are crucial. High-level standards and knowledge are necessary for designing effective protection schemes. The thesis centers around the design of a distance protection scheme for a medium-voltage system operating at 33kV. While line differential and overcurrent protection schemes are common for medium voltage systems, the study introduces the Mho distance scheme for short distribution lines. The 4-bus IEEE network serves as the basis for simulation in DigSilent and RSCAD power simulation software. Two distinct protection relay testing techniques are developed: Laboratory relay testing and Hardware-in-the-loop simulation using the RTDS (Real-Time Digital Simulator) simulator. The primary goal is to prevent significant damage to the 33kV network infrastructure during abnormal conditions. The Mho distance scheme is applied specifically to protect short distribution lines operating at 33kV. Simulations are conducted using DigSilent and RSCAD, demonstrating a comprehensive analysis of the designed protection scheme. Laboratory relay testing involves physical testing of protection functional on mho distance relays. The hardware-in-the-loop simulation uses the RTDS simulator to emulate real-world conditions for testing the protection scheme. In summary, the thesis contributes to the field of power system protection by proposing a Mho distance protection scheme for short distribution lines in a medium-voltage system. The comprehensive approach includes simulation in two software tools and the development of relay testing techniques to validate the effectiveness of the proposed mho distance protection scheme. This research is valuable for enhancing the reliability and performance of medium-voltage power systems.