Who developed a high voltage DC transmission system and in what year?

Rudolf Thury developed a high voltage direct current (HVDC) transmission system in 1899. This year is significant because it marks one of the early advancements in electrical engineering, where Thury's work focused on the efficient transmission of electricity over long distances, which was essential for the development of modern power systems. His contributions laid the groundwork for future high voltage transmission innovations and practices, demonstrating the importance of DC systems for long-range transmission compared to alternating current (AC) systems that were more common at the time.

The significance of this development is underscored by the subsequent establishment of HVDC technology as a vital component in modern electrical grids, especially for interconnecting power systems and minimizing transmission losses over vast distances.