Hybrid single‐carrier‐based pulse width modulation scheme for single‐phase three‐level neutral‐point‐clamped grid‐side converters in electric railway traction. Issue 13 (1st October 2016)

• Record Type: Journal Article
• Authors: Wang, Shunliang; Song, Wensheng; Zhao, Junhui; Feng, Xiaoyun
• Is Part Of: IET power electronics. Volume 9:Issue 13(2016)
• Page Start: 2500
• Page End: 2509
• Publication Date: 2016-10-01
• Subjects: railways -- rectifiers -- PWM power convertors -- power conversion harmonics -- harmonic distortion; hybrid single‐carrier‐based pulse width modulation scheme -- hybrid SCBPWM scheme -- dipolar SCBPWM scheme -- single‐phase three‐level grid‐side converters -- neutral‐point‐clamped grid‐side converters -- NPC converters -- electric railway traction -- AC traction power‐supply systems -- high‐order harmonics -- grid‐side rectifiers -- unipolar modulation modes -- dipolar modulation modes -- harmonic resonance -- voltage‐balancing task -- DC‐link capacitors -- separation coefficient -- unipolar double‐carrier‐based pulse width modulation -- total harmonic distortion -- line current -- carrier signal -- voltage fluctuation suppression; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2015.0656
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : AC traction power‐supply systems are vulnerable to the high‐order harmonics from grid‐side rectifiers, which are usually single‐phase three‐level neutral‐point‐clamped (NPC) converters. In this study, a dipolar single‐carrier‐based pulse width modulation (SCBPWM) scheme is first designed for the adopted NPC converter. Then, on the basis of the dipolar SCBPWM scheme, a novel hybrid SCBPWM scheme with both unipolar and dipolar modulation modes is proposed to improve high‐order harmonics and mitigate harmonic resonance. In addition, the voltage‐balancing task of the DC‐link capacitors of the NPC converter can be performed by fine adjustment of the separation coefficient in the hybrid SCBPWM. The salient features of the proposed scheme, as compared with the traditional unipolar double‐carrier‐based pulse width modulation, include: (1) lowered high‐order harmonics and total harmonic distortion of the line current; (2) only one carrier signal needed; and (3) voltage fluctuation suppression of the neutral point. Performance of the proposed hybrid SCBPWM scheme for the NPC converter is verified by experimental results.