虚拟阻容下的LCL型并网逆变器谐振抑制策略  

Grid-connected resonance suppression strategy of multi-LCL inverter based on virtual RC

作　　者：张继红[1] 刘云飞 卢星升 赵锐 吴振奎[1] 张晓明 ZHANG Jihong;LIU Yunfei;LU Xingsheng;ZHAO Rui;WU Zhenkui;ZHANG Xiaoming(School of Information Engineering,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学信息工程学院,内蒙古包头014010

出　　处：《电机与控制学报》2023年第9期168-179,共12页Electric Machines and Control

基　　金：内蒙古自治区自然科学基金(2021MS05039);内蒙古自治区重点研发与成果转化项目(2022YFHH0019)。

摘　　要：针对LCL滤波器自身谐振以及多逆变器并联谐振引发逆变器输出电压不稳、破坏电能质量等突出问题,建立了三相滤波等效电路模型,分析了谐振产生机理,重点设计了基于虚拟电容、虚拟电阻的优化组合谐振抑制策略。主要考虑虚拟电容可强化高频滤波能力,简化控制算法;虚拟电阻的设计旨在增大系统阻尼,增强逆变器并网谐振抑制效果。此外,引进电感电压前馈控制可降低LCL型逆变器系统阶次,优化对谐振的抑制效果,有利于提高系统稳定性和鲁棒性。最后,搭建了仿真模型和实验平台验证控制策略的可行性,并网电流波动性明显减弱,THD小于5%可平稳入网,说明了策略的有效性。Inverter output voltage instability,damage to power quality,and other notable issues are caused by LCL filter’s inherent resonance and many inverters operating in parallel.A three-phase filtering equivalent circuit model was developed,the resonance production mechanism was examined,and special focus was placed on the design of an optimum combined resonance suppression approach based on virtual capacitance and virtual resistance.This approach primarily considers how virtual capacitors can improve high frequency filtering performance and streamline the control method.The virtual resistance was designed to boost the grid-connected inverter system’s resonance suppression by increasing system damping.The quasi-PR controller and the inductive voltage feedforward control were added.When suppressing resonance,the quasi-PR controller prevents interference from circulating currents.Voltage feedforward control’s function was to lower the order of an LCL-type inverter system,which helps to increase system stability.Finally,in order to confirm that the control technique is feasible,a simulation model and an experimental platform were created.The volatility of the grid-connected current is significantly reduced,and THD less than 5%can smoothly enter the grid,which indicates effectiveness of the strategy.

关 键 词：并联逆变器 并网谐振 虚拟电容 虚拟电阻 准谐振控制器 电感电压前馈控制 

分 类 号：TM464[电气工程—电器]