Improved modulator for THD reduction in onboard generation of three phase AC voltage

AC voltage generation in rail applications (auxiliary services), usually employs optimized PWM feedforward schemes in order to control the inverter. In this kind of applications the THD reduction of the filtered output voltage together with the reduced weight of the static converters are the main goals to be reached. In order to achieve these objectives, the most commonly used optimized PWM techniques are going to be compared in terms of total harmonic distortion (THD), weighted total harmonic distortion (WTHD) and IGBT losses.