TY JOUR TI Improving the Efficiency of the Electric Locomotive Drive with a Controllable Converter for Traction Motor Excitation KW Electric drive of single-phase DC electric locomotives KW independent excitation of collector traction motors KW controlled semiconductor transistor excitation converter KW control algorithms JO Bulletin of scientific research results AU Mihal'chuk, N.L. AU Popov, Y.I. AU Savos'kin, A.N. AU Pudovikov, O.E. AU Chuchin, A.A. PY 2023 IS 2023 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"