See in #4 how you used the delay(500) to update the duty cycle I can't use that because after a while it will not be able to accommodate the times. I am making a three phase space vector modulated inverter and every period i will have to calculate new duty cycles to load into each channel. Depending on the supply frequency you want the period in which these duty cycle calues must be calculated will be extremely small. If you want to find out more detail about how this works you can take a look at this page:
https://hvdc.ca/webhelp/Master_Library_Models/HVDC_and_FACTS/Space_Vector_Modulation/SVM_Theory.htm