A New SVPWM Modulated Input Switched Multilevel Converter for Grid-Connected PV Energy Generation Systems

This paper proposes a new space vector pulsewidth modulation (SVPWM) strategy for a hybrid input switched multilevel converter for photovoltaic energy generation systems. The converter topology is a cascaded connection of input switched and H-bridge converters, which can provide 2N + 1 voltage levels for each phase. The proposed SVPWM strategy treats the multilevel converter as a two-level converter by introducing an offset vector. With a generated switching pattern, it is possible to obtain minimum number of switching-state transitions and switch the H-bridge close to line frequency; thus, the switching losses can be significantly reduced. The proposed SVPWM strategy has been realized on a seven-level converter to demonstrate the principle of operation. The advantages of the proposed scheme and architecture are verified by both simulation and experimental results.