Research methods of increase efficiency algorithms pulse width modulation for semiconductor inverter

The paper considers an electric drive with induction motor and semiconductor frequency converter. The structure of the frequency converter, which includes a three-phase bridge inverter based on fully controlled transistors, is considered. The algorithm of pulse width modulation, used at the majority of electric drives, is discussed. The characteristics and shortcomings of the algorithm are shown. An algorithm method to improve efficiency of the inverter is promodulation of the control signal. The efficiency of this method in different variations is given. The level of electromagnetic compatibility of inverter and efficiency of various control algorithms are analyzed. The conclusions about feasibility of using promodulation is drawn.