Switching loss characteristics of advanced DPWM methods using space vector based double switching clamping sequences

This paper analyzes the inverter switching loss characteristics of space vector based double switching bus-clamping sequences. The two sequences considered in detail are 0121 and 7212 sequences. Utilizing these two sequences and varying the zero state at a spatial angle ¿ = ¿ (where ¿ is between 0° and 60°) an infinite number of advanced discontinuous PWM (ADPWM) methods can be generated. It is a proven fact that, the double switching clamping sequences reduce the steady state line current distortion during high modulation indices significantly compared with the conventional SVPWM (CSVPWM) as well as the existing discontinuous PWM (DPWM) methods. But since in the double switching clamping sequences one of the three phases switches twice in a switching period, thus adding additional switching losses, it is necessary to analyze the PWM methods using these two sequences. Simulation results are presented for concluding the effectiveness of these methods in reducing the inverter switching losses.