Design and Investigation of a New Multilevel Inverter with Reduced Number of Semiconductors for Photovoltaic Systems

In this research, a single-phase multilevel inverter with a reduced number of switches and driver circuits is introduced for analysis in photovoltaic systems. The proposed multilevel inverter consists of two parts, basic circuit, and H-bridge, which are responsible for generating voltage levels and symmetry of voltage levels (positive and negative), respectively. The proposed basic circuit in this paper consists of six unidirectional switches and three input sources and doesn’t use any capacitors or diodes, which reduces the volume and complexity of the control system. In this paper, the seven-level proposed structure is simulated in the MATLAB/Simulink software and the utilized modulation to generate the output voltage levels is level shifted pulse width modulation. Moreover, photovoltaic systems are exploited to supply the proposed inverter’s input sources, which work with perturb and observe algorithm at the maximum power point. In the simulation section, the voltage, current, power waveforms of the photovoltaic system, and the voltage of the proposed inverter input sources are demonstrated, and the voltage and current waveforms of the inverter for different conditions such as radiation and modulation index change are given. Finally, to show the merits and features of the proposed topology, the inverter is compared with some recent symmetrical structures in terms of the number of components and the rated voltage of the switches.