Effective space vector modulation switching sequence for three phase Z source inverters

A new approach in the PWM technique is proposed through proper choice of active vectors and placement of a shoot through (ST) states for three phase Z source inverter (ZSI). Compared to the existing modulation method, the power conversion interval is maximum in this technique which improves the output voltage at higher modulation indices. Also with the inclusion of ST states, the number of switching is less avoiding the switching losses. The switching is performed at higher operating frequency which reduces the voltage stress and the size of LC components. In each sector, the ST interval is properly selected to improve the bus utilisation thus increases the voltage gain of ZSI. Furthermore, the analysis is performed by deriving the expression for the RMS flux ripple over a sub-cycle and evaluated in terms of switching instants which facilitates immediate comparison for all the presented methods. The proposed method is verified through the simulation and experimental results.