Experimental validation of metaheuristic and conventional modulation, and hysteresis control of the dual boost nine-level inverter

In this article, various modulation strategies and hysteresis-band control of a recently introduced dual-boost nine-level inverter (DB9LI) are implemented. DB9LI is a switched capacitor based inverter capable of generating symmetrical nine output voltage levels by employing a single DC source. The topology generates a boosted bipolar voltage at the output side without applying end-side H-bridge (usually employed to generate negative levels), which contrasts with some of the switched-capacitor topologies. The capacitors employed have an inherent self-balancing feature. Additionally, due to lower individual and total standing voltages, switches of low voltage ratings are required. As a result, the cost of switches and the inverter reduces considerably. Metaheuristic-based selective harmonic elimination and mitigation (SHE and SHM) and various sine-triangular pulse width modulation techniques are implemented and compared on various parameters. Finally, a robust eight-band hysteresis control is designed and implemented, which helps to obtain sinusoidal load current with a unity power factor. The modulation strategies and the hysteresis control are validated on the MATLAB simulation environment and an experimental prototype.