基于改进型加权电流控制的LCL型并网逆变器控制策略  

Control Strategy of LCL Grid-Connected Inverter Based on Improved Weighted Current Control

作　　者：凌志勇[1,2] 周志飞 李圣清 姚鸿德[1,3] LING Zhiyong;ZHOU Zhifei;LI Shengqing;YAO Hongde(School of Electrical and Information Engineering,Hunan University of Technology,Zhuzhou 412007,China;State Grid Zhuzhou Power Supply Compnay,Zhuzhou 412000,China;Hunan Engineering Research Center of Photovoltaic Microgrid Intelligent Control Technology,Zhuzhou 412007,China)

机构地区：[1]湖南工业大学电气与信息工程学院,湖南株洲412007 [2]国网湖南省电力有限公司株洲供电分公司,湖南株洲412000 [3]光伏微电网智能控制技术湖南省工程研究中心,湖南株洲412007

出　　处：《湖南电力》2023年第2期39-45,共7页Hunan Electric Power

基　　金：国家自然科学基金(51977072)。

摘　　要：针对传统加权平均电流(weighted average current,WAC)控制策略未考虑数字控制延时使系统出现相位滞后而导致系统带宽减小、鲁棒性差的问题,提出了基于准比例谐振控制和超前补偿器结合的WAC控制策略。首先,引入电容电流反馈,抑制反向谐振峰;其次,在逆变桥传递函数处串联超前补偿器,提高系统的相位裕度;最后,应用准比例谐振控制器作为电流调节器,提高基频增益、降低系统的静态误差。经仿真验证,所提控制策略对弱电网具有良好的适应能力,并网电流谐波畸变率从1.84%降低到0.26%,增强了系统的鲁棒性、改善了并网电流的质量。Aiming at the problems that the traditional weighted average current(WAC)control strategy does not consider the digital control delay,and causes the phase lag of the system,which leads to the reduction of system bandwidth and poor robustness,the WAC control strategy of combination of quasi-proportional resonance control and lead compensator is proposed.Firstly,the capacitor current feedback is introduced to suppress the reverse resonance peak.Secondly,the lead compensator is connected in series at the transfer function of the inverter bridge to improve the phase margin of the system.Finally,the quasi-proportional resonant controller is used as a current regulator to Increase the fundamental frequency gain and reduce the static error of the system.It is verified by simulation that the proposed control strategy has good adaptability to weak power grids,and the harmonic distortion rate of grid-connected current is reduced from 1.84%to 0.26%,thereby enhancing the robustness of the system and improving the quality of grid-connected current.

关 键 词：加权电流控制 数字控制延时 电容电流反馈 系统降阶 准比例谐振控制 

分 类 号：TM464[电气工程—电器]