PUBLICATIONS

This thesis presents a method to reduce switching losses and decrease the total harmonic distortion (THD) of current in a permanent magnet synchronous motor (PMSM) drive system using a current-based discontinuous pulse width modulation (DPWM) method and a dead-time compensation method. Switching losses are effectively reduced by implementing a phase current-based DPWM that sets the offset voltage according to the phase angle of the current and clamps the switch in the section where the absolute value of the phase current is the maximum. Additionally, determining the current polarity through the phase angle of the current and applying a dead time compensation voltage according to the current polarity allows for the reduction of the THD of the current by compensating for voltage distortion caused by dead time. The application of the current-based DPWM method and the dead-time compensation method significantly improves the efficiency of the PMSM drive system. The validity of the proposed method is verified through simulation and experimental results.