THD reduction in high power V/F drives by using hybrid synchronized Space Vector Pulse Width Modulation

Abstract

In modern power converters the PWM strategy shows the major concern in reduction of switching losses and Total Harmonic Distortion (THD). In high power traction drives, the switching frequency has to be reduced to limit the switching losses, as it becomes difficult to arrange cooling for the inverter if the switching losses are huge. Usually the maximum switching frequency is limited. There are many PWM techniques available to reduce the THD in inverter output among them Space Vector Pulse Width Modulation (SVPWM) gives better performance than any other techniques. Due to flexibility in the choice of switching state in SVPWM, there can be possibility of the six different SVPWM strategies, each having good performance at particular range of modulation index. By using all six strategies a new hybrid SVPWM strategy has been developed and the performance is compared with other PWM techniques for v/f drive of maximum switching frequency 450HZ with MATLAB13a.