摘要
为解决弱网阻抗变化时并网逆变器有源阻尼方法存在的阻尼失效问题,这里从考虑数字控制延时的有源阻尼阻抗特性出发,对弱网下有源阻尼失效的原因进行分析,提出了一种相位超前补偿的改进有源阻尼方法,减小数字控制延时对系统正阻尼区间的影响,拓宽了系统正阻尼区间,提高了谐振抑制效果,使并网逆变器在弱网下保持谐振阻尼的有效性和良好的稳定性。设计并搭建了一台LCL型中点箝位型(NPC)三电平并网逆变器实验样机,实验结果表明该方法可以拓宽系统正阻尼区间,使并网逆变器在不同的电网阻抗下能可靠稳定运行,提高其并网电流质量。
In order to solve the damping failure problem of the active damping method when the impedance changes in weak grid,the causes of active damping failure under weak grid are analyzed based on the characteristics of active damping impedance considering digital control delay.An improved active damping method with phase-lead compensation is proposed,which reduces the influence of the digital control delay on the positive damping interval and extends the positive damping interval of the system,improves the effect of resonance suppression.By applying this methoed,the grid-connected inverter can maintain the effectiveness of resonance damping and good stability in weak grid.An experimental prototype of the LCL-filtered neutral point clamped(NPC) three-level grid-connected inverter is built to verify the effectiveness of the proposed method.Experimental results show that the positive damping interval of the system has been extended,which can ensure the grid-connected inverter operate stably against grid impedance variation and improve the quality of grid currents.
作者
桂前进
江千军
钟成元
孙状
GUI Qian-jin;JIANG Qian-jun;ZHONG Cheng-yuan;SUN Zhuang(State Grid Anqing Power Supply Company,Anqing 246000,China;不详)
出处
《电力电子技术》
北大核心
2023年第2期18-21,共4页
Power Electronics
基金
国网安徽省电力有限公司科技资助项目(5212-D02001XN)
国家自然科学基金(52007129)。
关键词
并网逆变器
弱网
有源阻尼
正阻尼区间
grid-connected inverter
weak grid
active damping
positive damping interval