A Carrier-Based Multiswitch Virtual Space Vector Modulation With Dead-Time Effect Elimination for Multiport DC–AC Converters

Multiport dc–ac converter has gained attention due to its power density and low cost. However, in virtual space vector pulse width modulation (VSVPWM) where common-mode voltage (CMV) reduction and power control are considered, there are multiple switching actions in a period, which can be called multiswitch-VSVPWM (MS-VSVPWM). This leads to complex vector synthesis rules, and dead-time effect (DTE) needs to be analyzed due to variable port voltages. To simplify computation, a carrier-based MS-VSVPWM with DTE elimination is proposed. First, according to volt-second balance and dwell time relations, variable and fixed modulation waves are derived. Then, final output sequences are obtained by using phase opposition disposition (POD) carrier. Second, shifted modulation wave is derived on this basis. The drive signals are obtained by the variable/fixed modulation wave and the shifted modulation wave, respectively. Thus, DTE is eliminated on the premise of avoiding shoot-through of power switches. In addition, a variable shift value strategy is investigated to obtain the maximum shift value. Finally, the proposed method is verified experimentally on photovoltaic (PV)-battery hybrid system prototype, showing its high efficiency and relatively low output harmonics based on CMV reduction and power control.