三相四桥臂逆变器高频振荡机理分析及基于电流反馈的阻抗重塑方法  

High Frequency Resonance Mechanism and Impedance Reshaping Based on Current Feedback of Three-phased Four-legged Inverter

作　　者：廖玉茗 年珩[1] 李萌 孙丹[1] 胡彬 刘一鸣 LIAO Yuming;NIAN Heng;LI Meng;SUN Dan;HU Bin;LIU Yiming(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,Zhejiang Province,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电网技术》2023年第1期83-90,共8页Power System Technology

基　　金：国家自然科学基金项目(51977194)。

摘　　要：在分布式电网和配电网中,相较于三相三线制系统,由于三相四线制系统中存在额外的零序通路且零序分量也会引起高频振荡,导致现有的高频振荡抑制方法不再适用。分析了单电感滤波的三相四桥臂并网逆变器接入带并联补偿电容的电网时的高频振荡产生原因。为抑制正序、负序和零序分量引起的高频振荡,提出了一种基于电流反馈的阻抗重塑方法。该方法可以改变三相四桥臂逆变器的正序、负序和零序阻抗在高频段的幅值和相位,确保系统在高频段有足够的相位裕度。理论分析和硬件在环实验验证了所提出控制策略的正确性和有效性。In the distribution grid and the micro grid, compared to a three-phased three-wired system, the existence of an additional zero-sequence path in a three-phased four-legged grid-connected inverter system may cause a high-frequency resonance, which makes the existing high frequency resonance suppression methods inapplicable. This paper analyzes the causes of high-frequency resonance when a three-phase four-leg inverter with a single inductor filter is connected to a grid with parallel compensation capacitor. In order to suppress the high frequency resonance caused by the positive-sequence, negative-sequence and zero-sequence component, an impedance reshaping strategy based on the current feedback applied to a three-phased four-legged grid-connected inverter is proposed in this paper. This method simultaneously regulates the amplitude and phase of the positive-sequence, negative-sequence and zero-sequence impedances in the high frequency band, ensuring the sufficient phase margin of the inverter in the high frequency band. Theoretical analysis and experiments verify the correctness of the proposed control strategy.

关 键 词：三相四桥臂并网逆变器 高频振荡 阻抗重塑 

分 类 号：TM721[电气工程—电力系统及自动化]