Voltage droop control at point of common coupling with arm current and capacitor voltage analysis for distribution static synchronous compensator based on modular multilevel converter. Issue 8 (1st June 2016)

• Record Type: Journal Article
• Authors: Xu, Chen; Dai, Ke; Chen, Xinwen; Kang, Yong
• Is Part Of: IET power electronics. Volume 9:Issue 8(2016)
• Page Start: 1643
• Page End: 1653
• Publication Date: 2016-06-01
• Subjects: static VAr compensators -- voltage control -- power capacitors -- electric current control -- equivalent circuits -- power conversion harmonics -- reactive power control -- power distribution control; point‐of‐common coupling voltage droop control -- arm current analysis -- capacitor voltage analysis -- three‐phase double‐star‐type transformer‐less modular multilevel converters -- medium‐voltage distribution static synchronous compensators -- MMC‐DSTATCOM -- pulse‐width‐modulated cascaded half‐bridge modules -- steady‐state analysis -- project installation -- first component equivalent circuits -- second component equivalent circuits -- undetermined circulating second harmonic current modulation index -- undetermined circulating second harmonic actual modulation index -- internal active power control -- internal reactive power control -- external droop control -- three‐wire double‐star‐type transformer‐less modular multilevel converters -- downscaled power distribution system -- voltage 60 V -- apparent power 2 kVA; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2015.0728
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : This study presents a kind of three‐phase three‐wire double‐star‐type transformer‐less modular multilevel converters (MMCs) in medium‐voltage distribution static synchronous compensators (DSTATCOMs) application based on pulse‐width‐modulated cascaded half‐bridge modules. An advanced steady‐state analysis for arm current and capacitor voltage is presented to give the explicit converter performance evaluation in project installation. Two key equations based on first and second component equivalent circuits are formulated to obtain the undetermined circulating second harmonic current and actual modulation index. Based on the proposed analysis, the internal active and reactive power control and the external droop control for the voltage at the point of common coupling (PCC) are introduced for MMC‐DSTATCOM, respectively. The droop control enlarges the operation area of the converter and the PCC voltage is allowed to vary in a larger acceptable range. Experiment tests acquired from a 60 V/2 kVA prototype in a simplified downscaled power distribution system verify the accuracy of the analysis and the feasibility of the PCC voltage droop control simultaneously.