LCL-resonance damping strategies for grid-connected inverters with LCL filters: a comprehensive review

• 作者: Jinming XU Shaojun XIE
• 来源期刊: 现代电力系统与清洁能源学报(英文)
• 学科: 工学
• 关键词: LCL filter GRID-CONNECTED INVERTER RESONANCE DAMPING State FEEDBACK Investigation
• 年，卷（期）: 2018,（2）
• 页码范围: 292-305
• 页数: 14页
• 分类号: TM464

摘要

Grid-connected LCL-filtered inverters are commonly used for distributed power generators. The LCL resonance should be treated properly. Recently, many strategies have been used to damp the resonance, but the relationships between different damping strategies have not been thoroughly investigated. Thus, this study analyses the essential mechanisms of LCL-resonance damping and reviews state-of-the-art resonance damping strategies.Existing resonance damping strategies are classified into those with single-state and multi-state feedback. Singlestate feedback strategies damp the LCL resonance using feedback of a voltage or current state at the resonance frequency. Multi-state feedback strategies are summarized as zero-placement and pole-placement strategies, where the zero-placement strategy configures the zeros of a novel state combined by multi-state feedback, while the poleplacement strategy aims to assign the closed-loop poles freely. Based on these mechanisms, an investigation of single-state and multi-state feedback is presented, including detailed comparisons of the existing strategies. Finally,some future research directions that can improve LCL-filtered inverter performance and minimize their implementation costs are summarized.