A detailed analysis of a seven-level selective harmonic elimination pulse-width modulation method suitable for multilevel DC-AC converters is presented in this study. Solution trajectories that cover the normal range ...
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A detailed analysis of a seven-level selective harmonic elimination pulse-width modulation method suitable for multilevel DC-AC converters is presented in this study. Solution trajectories that cover the normal range of modulation indices typical for the operation of multilevel inverters are documented. The properties and characteristics of these solutions with regard to the distribution of switching instants (angles) to the levels of the waveform are also reported. Selected simulation and experimental results are included for both steady state operation and under dynamic changes of the modulation index and the output frequency. The results confirm the effectiveness of the method.
selective harmonic elimination pulse-width modulation (SHE-PWM) works at low-frequency switching, which reduces switching losses, device stress, and increases energy conversion efficiency. So, it can be an effective c...
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selective harmonic elimination pulse-width modulation (SHE-PWM) works at low-frequency switching, which reduces switching losses, device stress, and increases energy conversion efficiency. So, it can be an effective control strategy for multilevel inverter working on medium-voltage, high-power industrial energy conversion application. It provides desired output voltage by retaining the requested fundamental component as well as eliminating some low-order harmonics. The application of SHE-PWM in industries is having an influence on precise solvability of complex and non-linear equations. This study presents two recently reported optimisation techniques, namely backtracking search algorithm and differential search algorithm (DSA) for obtaining a more accurate solution of the harmonics elimination problem. The superiority of the proposed optimisation algorithms over the well known ancient algorithm such as genetic algorithm, BEE algorithm and particle swarm optimisation have been established by a comparative study with respect to the possibility of attaining global minima, the rank of convergence rate, and inverter performance analysis. Simulation and experimental results validate the efficacy of the DSA optimisation technique for calculating more precise switching angles that totally eliminate 5th- and 7th-order harmonics with fulfilling the requested fundamental component.
To improve the reliability in high voltage and high power applications, the fault-tolerant control of three-level neutral-point-clamped (3L-NPC) inverter has been deeply studied. In this paper, the eight-switch three-...
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To improve the reliability in high voltage and high power applications, the fault-tolerant control of three-level neutral-point-clamped (3L-NPC) inverter has been deeply studied. In this paper, the eight-switch three-phase inverter (ESTPI) is selected as the fault-tolerant topology of 3L-NPC inverter, and the synchronous modulation strategy of ESTPI is discussed for some particular application situation working at low switching frequency. The harmonic distribution of the ESTPI is analyzed firstly under synchronous modulation. To eliminate the specific low-order harmonics including the frequency tripling harmonics, the selective harmonic elimination pulse-width modulation (SHEP WM) based synchronous modulation strategy for the ESTPI is proposed in this paper, which can ensure a good performance of output voltage for 3L-NPC inverter under fault-tolerant operation. The effectiveness and feasibility of the proposed method are verified by the experimental results.
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