Changing PWM Firing Angle

Hey guys,

Going to try and keep it short. I'm trying to design a 3 Phase Inverter, where I am controlling my IGBT Diode's with a PWM Generator. In order to control the level of the AC Output Voltage I am trying to get my PWM Generator output to look like the attached sketched image.

I'm having a hard time understanding whether its possible to have a PWM Generator output like the one in the attached sketch? That PWM Generation is what I need for my desired output. I'm unsure whether its possible for Triggers 1 and 2 to be both off at the same time (and the same for T3&4, & T5&6).

Any help is much appreciated! Ali.