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Comparison of Low-Frequency-Commutation Modulation Techniques in a Symmetrical Cascaded H-Bridge Multilevel Inverter
  • Pedro Martín García Vite,
  • Juan H. Almazán Covarrubias,
  • Juan M. Ramírez Arredondo
Pedro Martín García Vite
Instituto Tecnologico de Ciudad Madero
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Juan H. Almazán Covarrubias
Instituto Tecnologico de Ciudad Madero

Corresponding Author:[email protected]

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Juan M. Ramírez Arredondo
Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Guadalajara
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Abstract

Among the power inverters, modular multilevel converters (MMC) have gained popularity due to their advantages over conventional two-level inverters. Although the MMC utilizes more power switches than traditional inverters, the former exhibits notable benefits such as low total harmonic distortion, low switching losses with lower voltage stress, high power quality, reduced electromagnetic interface, and modularity with numerous degrees of freedom to synthesize output waveforms. Concerning the synthesized voltage quality, several low-frequency modulation techniques have been proposed to produce output voltage with low harmonic content. A particular case of study consisting of a three-phase even-level MMC inverter is taken as a benchmark to comparatively evaluate four methods for synthesizing high-quality output voltage. The employed techniques are ( i) selective harmonic elimination (SHE), ( ii) generalized SHE, ( iii) THD Voltage Minimization, and ( iv) Optimum Nearest Level Modulation, selected based on the phase and line-to-line output voltage THD. The model is formulated to compute the commutating angles to control the MMC submodules. Simulations show individual performance under the same operating conditions. A lab-scale prototype is built to corroborate the theoretical approach. The results allow the selection of the most convenient modulation technique based on the number of commutations and harmonic spectrum.
13 Mar 2023Submitted to International Journal of Circuit Theory and Applications
14 Mar 2023Assigned to Editor
14 Mar 2023Submission Checks Completed
14 Mar 2023Review(s) Completed, Editorial Evaluation Pending
31 Mar 2023Reviewer(s) Assigned
08 May 2023Editorial Decision: Revise Major