Research of dependences of idle losses of transformers TM-400/10 on voltage according to synchronous measurementsPavel Zvada, Evgenii Zelenskii, Yuri Kononov, Svetlana Kostyukova and Evgeny DerninE3S Web Conf., 279 (2021) 01022DOI: https://doi.org/10.1051/e3sconf/202127901022