Voltage Distortion Minimization in Cascaded H-Bridge Inverters
Multilevel inverters based on the series connection of H-bridges are the most modular multilevel inverter family. The use of a large number of these devices connected in series, controlled by modulation based on the fundamental frequency, allows to obtain an output voltage of the inverter with low harmonic distortion and low losses in the inverter. This paper analyses the main characteristics of a fundamental frequency modulation method applied to multilevel inverters based on cascaded H-bridges (CHB). Particular emphasis is given to the harmonic distortion of the output voltage and the range of variation of the amplitude of the fundamental component in static and dynamic conditions. It is also discussed the implementation of the algorithm in real-time and in an FPGA platform. Simulation and experimental results are presented with a different number of H-bridges.
KeywordsCascaded H-bridge inverters Multilevel inverters Square-wave modulation Total harmonic distortion
This work was financially supported by: Project POCI-01-0145-FEDER-006933/SYSTEC - Research Center for Systems and Technologies funded by FEDER funds through COMPETE 2020 and by national funds through the FCT/MEC, and co-funded by FEDER, in the scope of the PT2020 Partnership Agreement. Abel A. Ferreira gratefully acknowledges the financial support from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme FP7/2007-2013/ (Grant Agreement no. 317221), project title MEDOW.
- 5.Dahidah, M.S., Konstantinou, G., Agelidis, V.G.: A review of multilevel selective harmonic elimination PWM: formulations, solving algorithms, implementation and applications. IEEE Trans. Ind. Electron. 30(8), 4091–4116 (2015)Google Scholar
- 9.Faria, J., Martins, A.: Analysis and characterization of a square-wave modulation method for single-phase cascaded H-bridge multilevel inverters. In: Proceedings of the International Conference on Renewable Energies and Power Quality (ICREPQ 2012), 28–30 March 2012, Santiago de Compostela, Spain (2012)Google Scholar