Scientific paper ID 2745 : 2025/3

This report presents the stages of implementing a loading device in the laboratory base of the Department of ”Power Supply and Electrical Equipment of Transport” at the ”Todor Kableshkov” Higher Transport School, in order to provide realistic conditions for experimental research of relay protections used in an alternating current traction power supply system (TSS).

A teaching and research environment has been built in which the load device acts as a controllable load model, allowing simulation of various operational and emergency operating modes of TPPs. This system is used to perform measurements, tests and analyses of the behavior of digital relay protections under variable operating conditions.

The main goal is to present an integrated approach, including modern measuring and protection equipment, real protection algorithms and newly developed laboratory exercises, applicable both in student training and in research activities.

The created configuration provides a practical basis for analyzing the efficiency, speed, selectivity and adaptability of protection systems in real or simulated situations typical of railway electric transport.

The report emphasizes the importance of realistic laboratory training, its connection with the ments of modern energy infrastructure and the need for adequate engineering training for the design and maintenance of relay systems in TPPs.