低开关频率下LCL型并网变流器复矢量分析及改进解耦控制  

Complex Vector Analysis and Improved Decoupling Control for LCL-Filtered Grid-Connected Converters With Low Switching Frequency

作　　者：肖琦 唐芬[1] 辛振 周家宇 陈鹏飞[1] Poh Chiang Loh 姜久春[3] XIAO Qil;TANG Fenl;XIN Zhen;ZHOU Jiayu;CHEN Pengfei;Poh Chiang Loh;JIANG Jiuchun(National Active Distribution Network Technology Research Center（Beijing Jiaotong University）,Haidian District,Beijing 100044,China;Department of Electronic Engineering,Chinese University of Hong Kong,Hong Kong 999077,China;Collaborative Innovation Center of Electric Vehicles in Beijing（Beijing Jiaotong University）,Haidian District,Beijing 100044,China)

机构地区：[1]国家能源主动配电网技术研发中心(北京交通大学),北京市海淀区100044 [2]香港中文大学电子工程系,香港999077 [3]北京电动车辆协同创新中心(北京交通大学),北京市海淀区100044

出　　处：《电网技术》2018年第9期2821-2829,共9页Power System Technology

基　　金：国家重点研发计划项目(2016YFB0900500)~~

摘　　要：同步旋转坐标系（dq）下的比例积分控制在并网变流器中得到广泛应用。由于滤波器和数字延迟的dq模型均存在轴间耦合并且两者相互影响,低开关频率下LCL型并网变流器的建模和解耦控制变得极具挑战。针对该问题,在对同步旋转坐标系下的LCL型并网变流器采用复矢量进行建模的基础上,通过双边频响特性曲线和零极点图对传统状态反馈和相位补偿进行了系统分析,揭示了不同位置相位补偿对系统相位裕度和解耦性能的影响关系,在此基础上提出了一种改进解耦控制方法,通过在状态反馈环内和调节器输出端依次设计相位补偿,在有效调节和改善动态性能的同时保证系统具有较好的解耦性能。最后,仿真及实验结果表明所提方法具有很好的解耦效果,同时能有效减小系统超调量和调节时间。Proportional integral（PI） control in synchronous rotating frame（dq） is widely applied in grid-connected converters. As axe-cross-couplings exist both in the filter and delay models of dq frame and the cross-couplings interact each other, modeling and decoupling of LCL-filtered grid-connected converter with low switching frequency become much more challenging. To address this issue, based on modeling of LCL-filter grid-connected converters in dq frame with complex vector, a systematic analysis for traditional state feedback and phase compensation is conducted with double-sided frequency response and pole-zero map, where the effects of phase compensation at different positions on phase margin and decoupling effect are revealed. Based on this, an improved decoupling control strategy is proposed to effectively regulate and improve system dynamic performance and ensure good decoupling effect at the same time by respectively designing phase compensations at output of regulator and within state feedback loop. Finally, simulation and experimental results show that the proposed method can provide good decoupling effect and reduce overshoot and settling time effectively.

关 键 词：解耦控制 相位补偿 状态反馈 低开关频率 LCL滤波器 复矢量 

分 类 号：TM721[电气工程—电力系统及自动化]