New-age condition monitoring of on-load tap changing transformers in distributed energy systems for Industry 4.0

Sustainability is a core focus of modern advancements in energy and power systems. Citing the significance of on-load tap changing transformers (OLTCTs) in distributed energy systems, researchers and industries have studied various smart wireless technologies through which their performance and possible failure might be monitored. This study aims to provide a critical outlook on the operation of OLTCTs and on the various implementations of IoT that have shown potential in smart condition monitoring of OLTCTs. To the knowledge of the authors, this is the first extensive study focusing on the amalgamation of conventional OLTCTs with new-age smart wireless frameworks that allow optimized operation and maintenance. The major finding of this article is to identify and exemplify the advancement possibilities of OLTCT in distributed energy systems. The authors aim to pinpoint current hotspots of development in the OLTCT and condition monitoring domain, as well as nascent areas which are likely to be the focus of research in the future to circumvent current gaps in this domain. As we progress towards Industry 4.0, such hybrid frameworks shall become the new norm and hence this study is a significant foundation for researchers looking to further advance development in this domain. Initially, the work builds a panoramic view of distributed energy systems with a distinct understanding of the specific role of OLTCTs within this assembly. Following this, a discussion is undertaken about the sensory and actuation systems required to make OLTCTs compatible with modern monitoring systems. Finally, the study concludes with the envisioned future of IoT-based condition monitoring of OLTCTs and their challenges.