DC‐link voltage control strategy for reducing capacitance and total harmonic distortion in single‐phase grid‐connected photovoltaic inverters. Issue 8 (1st August 2015)

• Record Type: Journal Article
• Authors: Hu, Yihua; Du, Yang; Xiao, Weidong; Finney, Stephen; Cao, Wenping
• Is Part Of: IET power electronics. Volume 8:Issue 8(2015)
• Page Start: 1386
• Page End: 1393
• Publication Date: 2015-08-01
• Subjects: voltage control -- invertors -- power supply quality -- power generation protection -- photovoltaic power systems; dc‐link voltage control strategy -- capacitance reduction -- total harmonic distortion -- THD -- single‐phase grid‐connected photovoltaic inverters -- two‐stage topology -- active power -- comprehensive DCL strategy -- normal system operation -- pulse‐skipping control -- power quality -- light power conditions -- active protection scheme; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2014.0453
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : High‐volume capacitance is required to buffer the power difference between the input and output ports in single‐phase grid‐connected photovoltaic inverters, which become an obstacle to high system efficiency and long device lifetime. Furthermore, total harmonic distortion becomes serious when the system runs into low power level. In this study, a comprehensive analysis is introduced for two‐stage topology with the consideration of active power, DC‐link (DCL) voltage, ripple and capacitance. This study proposed a comprehensive DCL voltage control strategy to minimise the DCL capacitance while maintaining a normal system operation. Furthermore, the proposed control strategy is flexible to be integrated with the pulse‐skipping control that significantly improves the power quality at light power conditions. Since the proposed control strategy needs to vary DCL voltage, an active protection scheme is also introduced to prevent any voltage violation across the DCL. The proposed control strategy is evaluated by both simulation and experiments, whose results confirm the system effectiveness.