Control of a 3-Phase 9-level Symmetrical Utility Interactive Inverter for Renewable Energy Applications

In this paper, a three-phase, 9-level symmetric, utility interactive inverter that is designed for the solar powered renewable energy applications is presented. This inverter topology, designed with only 10 IGBT switches, features a lower number of switches compared to other 9-level conventional inverters that require more semiconductor switches for the operation. A comprehensive examination of multilevel carrier based sinusoidal PWM technique using phase opposition disposition (POD) is provided in this paper. A 3-phase solar powered 9-level symmetric Multilevel Inverter (MLI) connected to the utility grid is designed and its implementation is substantiated with the PSIM ® simulator. The feedback control algorithm of this utility interactive inverter is implemented using $\mathbf{C}$ programming language such that the control section’s code can be embedded directly in the feedback controller without any modifications in the microprocessor as in the case of Hardware-in-the-loop (HIL) simulation.