TY CONF TI DESIGN OF UNIVERSAL CONTROL SYSTEM FOR H-BRIDGE MULTILEVEL CONVERTER KW medium voltage frequency converter KW multi-level inverter KW pulse-width modulation KW low-voltage cell JO CAD/EDA/SIMULATION IN MODERN ELECTRONICS 2021 AU Chepiga, A.A. AU Anuchin, A.S. PY 2021 PB Bryansk State Technical University