Abstract

Power quality disturbances, such as voltage sags, harmonics, and transients, pose significant challenges to electrical power systems, particularly impacting the performance and lifespan of transformers, which are essential components in power distribution networks. Poor power quality leads to inefficient operation, accelerated wear, and increased maintenance costs of transformers. This study aims to develop a model that simulates the effects of these disturbances on transformer performance, with the objectives of analyzing how voltage sags, harmonics, and transients influence transformer efficiency and lifespan, as well as assessing the effectiveness of protective devices in mitigating these effects. The research employs Ansys Maxwell and MATLAB/Simulink to model transformer behaviour under varying power quality conditions, introducing disturbances such as voltage sags and harmonic distortions to simulate real- world scenarios. The study focuses on medium-voltage transformers typically found in industrial and residential systems. The findings reveal that power quality disturbances, particularly voltage sags and harmonics, increase core losses and thermal stress, reducing transformer efficiency. However, transformers equipped with harmonic filters and voltage stabilizers showed improved resilience, maintaining optimal performance and extending operational life, thus reducing maintenance costs. This study provides valuable insights into enhancing transformer resilience and offers solutions for improving the design and protection of transformers in power systems.