极弱电网下基于电压前馈的并网逆变器输出阻抗重塑  

Output Impedance Reshaping of the Grid-connected Inverter Based on Voltage Feedforward in an Extremely Weak Grid

作　　者：杨博 周旭 张玉林 李乃湖 YANG Bo;ZHOU Xu;ZHANG Yulin;LI Naihu(Shanghai CHINT Power System Co.,Ltd.,Shanghai 201600,China;CHINT Croup R&D Center(Shanghai)Co.,Ltd.,Shanghai 201600,China)

机构地区：[1]上海正泰电源系统有限公司,上海201600 [2]正泰集团研发中心(上海)有限公司,上海201600

出　　处：《新型电力系统》2023年第3期293-302,共10页NEW TYPE POWER SYSTEMS

摘　　要：极弱电网下并网逆变器存在稳定性问题和低频段电流谐波放大问题。为此,首先,构建了逆变器q轴输出阻抗模型,分析了并网逆变器系统的稳定裕度;其次,建立了低频段电流谐波放大分析方法;然后,基于电压前馈构建了输出阻抗重塑的精确传递函数,并在保证输出阻抗相位提升幅度不产生较大偏差的情况下,对前馈电压传递函数进行了简化与优化;最后,搭建了硬件在环仿真平台对所提方法进行了验证。结果表明,所提低频段谐波放大分析方法和基于电压前馈的输出阻抗重塑策略是有效的,并网逆变器的稳定性和谐波特性有较大改善。论文研究可为并网逆变器在极弱电网下的稳定性提升和低频谐波电流抑制提供参考。The stability problem and the current harmonic amplification problem exist in grid-connected inverters in extremely weak grids.For this reason,firstly,the q-axis output impedance model is constructed,and the stability margin of the grid-connected inverter is analyzed.Secondly,a low-frequency-band current harmonic amplification analysis method is established.Then,an accurate transfer function of the output impedance reshaping strategy is developed based on voltage feedforward.The feedforward voltage transfer function is simplified and optimized under the condition that the amplitude of output impedance phase boosting does not produce large deviation.Finally,a hardware-in-loop simulation platform is built to validate the proposed method.The results show that the proposed low-frequency harmonic amplification theory and output impedance reshaping strategy based on voltage feedforward are effective,and the stability and harmonic characteristics of the grid-connected inverter are significantly improved.The research in this paper can provide references for the stability improvement and low-frequency harmonic current suppression of the grid-connected inverters in the extremely weak grids.

关 键 词：极弱电网 输出阻抗 稳定性 电流谐波放大 阻抗重塑 

分 类 号：TM464[电气工程—电器]