Optimised phase disposition pulse‐width modulation strategy for hybrid‐clamped multilevel inverters using switching state sequences. Issue 7 (1st July 2015)

• Record Type: Journal Article
• Authors: Ma, Mingyao; He, Xiangning; Cao, Wenping; Song, Xueguan; Ji, Bing
• Is Part Of: IET power electronics. Volume 8:Issue 7(2015)
• Page Start: 1095
• Page End: 1103
• Publication Date: 2015-07-01
• Subjects: PWM invertors -- optimisation -- power capacitors -- power system harmonics -- voltage control; optimised phase disposition pulse‐width modulation strategy -- hybrid‐clamped multilevel inverters -- switching state sequences -- phase shift angle -- switching state change -- modulation optimisation purposes -- voltage imbalance problem -- dc‐link capacitors -- low‐order harmonic reduction -- power 6 kW; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2014.0748
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : This study describes an optimised modulation strategy based on switching state sequences for the hybrid‐clamped multilevel converter. Two key control variables defined as 'phase shift angle' and 'switching state change' for a five‐level hybrid‐clamped inverter are proposed to improve all switches' operation, and by changing their values, different control methods can be obtained for modulation optimisation purposes. Two example methods can solve the voltage imbalance problem of the dc‐link capacitors and furthermore avoid two switches' simultaneous switching transitions and improve the inverter's performance as compared with the traditional phase disposition pulse‐width modulation strategy. A 6 kW prototype inverter is developed and a range of simulation and experiments are carried out for validation. It is found that simulation and experimental results are in a good agreement and the proposed modulation strategy is verified in terms of low‐order harmonic reduction.