Novel random pulse position modulation for three-phase four-leg inverters. (May 2018)

• Record Type: Journal Article
• Authors: Pan, Tinglong; Wu, Haopeng; Fu, Chenghao; Wu, Dinghui
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 232:Number 5(2018)
• Page Start: 541
• Page End: 549
• Publication Date: 2018-05
• Subjects: Harmonic reduction -- three-phase four-leg inverters -- randomized pulse position modulation -- randomization effect -- Well Equidistributed Long-period Linear algorithm; Mechanical engineering -- Periodicals; Automatic control -- Periodicals; Systems engineering -- Periodicals; 621.3
• DOI: 10.1177/0959651818760110
• Languages: English
• ISSNs: 0959-6518

Abstract

Aiming at improving the harmonic spectra spreading effect, two randomized pulse position modulation strategies are proposed for three-phase four-leg inverters. Based on the volt-second balance law and the fixed switching frequency, the first proposed strategy places the center randomly during one carrier cycle with a limited degree of freedom, and the second proposed strategy randomly changes the carrier slope in each carrier cycle. To get better randomization effect of the proposed strategies, Well Equidistributed Long-period Linear algorithm was introduced to generate random numbers. In order to verify the validity of the proposed strategies, the modulation strategies are implemented with dSPACE DS1007-based real-time operating system. The experimental results show that the proposed strategies have dispersed the discrete harmonics to a wider sideband. Compared with the first strategy, a larger degree of freedom can be achieved in the second proposed strategy with lower harmonic spikes.