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.

This paper presents new and efficient modulation techniques applied on the recently introduced compact nine-level switched-capacitor inverter (C9LSCI). The paper also discusses the performance of the inverter under selective harmonic elimination (SHE) and mitigation (SHM) based on the heuristic Bat-Algorithm (BA) technique. Two new modulation techniques employing CD-type carrier waves and M-type carrier waves are proposed, showing a rise in efficiency, an increase in RMS voltage, reduction in capacitor voltage ripple, and a reduction in harmonic distortion (THD). Four recently introduced modulating signals, namely the third harmonic injection, thirty-degree bus clamped PWM (THTDBCPWM), third harmonic injection sixty-degree bus clamped PWM (THSDBCPWM), one pole clamped PWM (OPCPWM). Loss balancing two-pole clamped PWM (LBTPCPWM) are applied to the inverter with the proposed carriers, and a comparative analysis is carried out on different performance parameters. The proposed carriers' efficacy in Alternate Phase Opposition Disposition (APOD), Phase Opposition Disposition (POD), and Phase Disposition (PD) is validated.Further, Bat algorithm (BA) is applied as a heuristic approach to determine the optimum angles for the application of SHE and SHM. The efficacy of all the above techniques on the C9LSCI is verified in MATLAB/Simulink environment and further validated on an experimental setup.

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In this paper, a novel integrated SHE -NLC control is proposed for the mitigation of unwanted lower-order harmonics in the cascaded H-bridge multilevel inverter. The proposed algorithm has been developed by hybridizing the NLC and SHE methods, in an attempt to keep the merits of both the individual control. The switching angles and nearest levels are calculated by applying the Genetic Algorithm (GA). The proposed technique reduces the calculation time and implementation complexity, thus can be a viable alternative to the real time implementation for SHE. Integrated NLC-SHE control is tested by varying the modulation index and load dynamics. This technique resulted in the reduction in Total Harmonic Distortion (THDs) in load voltage and current. Comparative analysis of NLC, SHE and Integrated NLC-SHE technique is also performed on the CHB nine-level inverter. There is significant reduction in voltage and current THD values and power losses. Efficiency of the inverter is increased. The efficacy of the proposed control CHB nine-level is tested on MATLAB Simulink environment and further validated by experimental results.

This work presents hysteresis control applied to UXE-type inverter topology with a PI (Proportional Integral) controller, where thegains are derived by Particle Swarm Optimization (PSO). The investigated UXE inverter can generate a thirteen level output voltage waveform, which results in lower switching losses. It can boost the output voltage to 1.5 times the applied input DC source voltage. Satisfactory inverter operation is ensured by employing twelve-band hysteresis current control. The tuning of the PI controller required for the closed-loop hysteresis current control is achieved by nature-inspired PSO algorithm. A comparative analysis is also performed after obtaining the results applying natureinspired PSO and conventional Ziegler Nichols (ZN) methods. The effectiveness of the control strategy is verified in the MATLAB Simulink and further validated in experimentusing TMS320F28379D and also with Typhoon Hardware in Loop Technology.