摘要
加权平均电流(WAC)控制因其对并网逆变器固有的降阶特性而备受关注。然而,数字控制延时引起的系统反向谐振峰易导致传统WAC控制失效,并网逆变器对弱电网下电网阻抗的适应范围减小。鉴于此,本文不从WAC控制的降阶角度出发,而是通过逆变器与电网互联系统等效阻抗模型的网侧电流稳定性角度重新审视,提出一种采用LLCL滤波并网逆变器的前馈复矢量滤波器改进型WAC控制策略,用以提升并网逆变器等效输出阻抗在低频域的相位,可使其在奈奎斯特全频域内的相位均高于-90°,进而增强系统的稳定性。最后,通过仿真分析验证了所提控制策略的有效性。
The weighted average current(WAC)control strategy has attracted much attention because of its lower-order effect on grid-connected inverters.However,the system reverse resonant peak caused by digital control delay causes the traditional WAC control to fail,and the inverter’s adaptation range to the grid impedance under the weak power grid is reduced.In view of this,this article does not proceed from the perspective of WAC control reduction,but re-examines it from the perspective of grid-side current stability of the equivalent impedance model of the inverter and grid interconnection system.An improved WAC control strategy of feedforward complex vector filter using LLCL grid-connected inverter is proposed to improve the phase of the equivalent output impedance of the grid-connected inverter in the low-frequency domain.It can make the phase in the full frequency domain of Nyquist higher than-90°,thereby enhancing the stability of the system.Finally,theoretical and simulation analysis verify the effectiveness of the proposed control strategy.
作者
杨明
杨杰
赵铁英
郑晨
韦延方
YANG Ming;YANG Jie;ZHAO Tieying;ZHENG Chen;WEI Yanfang(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454003,China;State Grid Henan Electric Power Research Institute,Zhengzhou 450052,China)
出处
《电机与控制学报》
EI
CSCD
北大核心
2023年第8期109-121,共13页
Electric Machines and Control
基金
国家自然科学基金(U1804143,61703144)
河南理工大学青年骨干教师资助计划(2020XQG-18)
河南省矿山电力电子装置与控制创新型科技团队基金(CXTD2017085)。
关键词
加权平均电流控制
数字控制延时
反向谐振峰
等效阻抗模型
复矢量滤波器
weighted average current control strategy
digital delay
reverse resonant peak
equivalent impedance model
complex vector filte
