HVDC technologies in electric power transmission: International practices and development pathways in KazakhstanDaulet Akhatov, Bakhyt Zhautikov, Galina Sivyakova, Alexandr Nikulshin, Valery Druzhinin, Saule Kamarova, Yelena Kuntush and Tatyana SiverskayaE3S Web Conf., 638 (2025) 01005DOI: https://doi.org/10.1051/e3sconf/202563801005