Design and Performances of Thyristor-Based Electronic On-Load Tap Changer

On-load tap changers (OLTCs) are critical components in modern power grids, serving to regulate grid voltage by adjusting the effective turns ratio of transformers. However, the deep integration of renewable energy demands enhanced switching cycle capabilities and faster tap-changing speeds. To meet these demands, this paper presents the design and implementation of a modular, thyristor-based electronic OLTC (e-OLTC) tailored for distribution transformers. By replacing mechanical contacts with semiconductor devices, the proposed e-OLTC achieves rapid response, virtually unlimited number of switching cycles, and minimal maintenance requirements. The functionality and dynamic performance of the proposed e-OLTC are comprehensively validated through both RT-hardware-in-the-loop (RT-HIL) simulations and a dedicated experimental prototype of the basic unit under varying load conditions.