New Nine-Level Cascade Multilevel Inverter with a Minimum Number of Switches for PV Systems

Abstract

To support the grid system with high power quality from photovoltaics (PVs) and reduce the partial shading condition (PSC) effect of the PV system, as well as the mismatch power issue, in this study, we present a simple single-phase, nine-level cascade inverter architecture for photovoltaic (PV) systems with a minimum number of power components and passive parts. This reduction in the number of switches decreases the switching losses and the number of driving circuits, which causes a reduction in the complexity of the control circuit and hence reduces the cost and size. The suggested inverter shows a lower output voltage total harmonic distortion (THD) and unity power factor. In addition, this inverter’s control and switching techniques are far simpler than those of recently published designs. To evaluate the performance of the proposed inverter, we performed a comparison of the cascaded multilevel inverter (CMLI) topology, which required recent cascade topologies with the same nine voltage levels. The comparison depends on parameters such as the number of components (diode and capacitors) and the number of active switches in the inverter, in addition to total harmonic distortion. MATLAB/Simulink models for a grid-tied solar system PV application driven by the proposed nine-level inverter were built for design and validation.