电网电压畸变下的单相级联H桥变流器无锁相环控制  

Single-phase Cascaded H-bridge Converter Control Without Phase-locked Loop Under Distorted Grid Voltage Conditions

作　　者：杨达亮[1,2] 张轩 陈爽 陈家豪 YANG Daliang;ZHANG Xuan;CHEN Shuang;CHEN Jiahao(Guangxi Key Laboratory of Power System Optimization and Energy Technology(Guangxi University),Nanning 530004,Guangxi Zhuang Autonomous Region,China;College of Electrical Engineering,Guangxi University,Nanning 530004,Guangxi Zhuang Autonomous Region,China)

机构地区：[1]广西电力系统最优化与节能技术重点实验室(广西大学),广西壮族自治区南宁市530004 [2]广西大学电气工程学院,广西壮族自治区南宁市530004

出　　处：《电网技术》2021年第2期751-757,共7页Power System Technology

基　　金：国家自然科学基金项目(61861003)。

摘　　要：传统单相级联H桥(cascaded H-bridge,CHB)变流器采用dq控制,在电网电压畸变情况下,控制性能受锁相环影响较大。为此,文章提出电网电压畸变下的单相CHB变流器无锁相环控制方法。首先通过构造级联延迟信号消除(cascaded delayed signal cancellation,CDSC)模块,快速提取电网电压基波信号;然后将其矢量化,根据瞬时有功功率、无功功率和电压、电流之间的关系计算参考电流信号,完成对有功电流、无功电流的独立控制。此外,通过电网电压前馈进一步减轻电网电压畸变对电网电流的影响;并由此完成各H桥直流侧的电压平衡控制。与传统的dq控制相比,无锁相环控制方法消除了构造正交电流信号造成的延时。三单元CHB变流器的仿真和实验结果证明了所提方法在电网电压畸变情况下的有效性。The single-phase cascaded H-bridge(CHB) converter is under conventional dq control, and its control performance in distorted grid voltage conditions is sensitive to the phase-locked loop(PLL). Therefore, a phase-locked loopless control method for the single-phase CHB converter under distortion grid voltage is proposed in this paper. Firstly, the fundamental voltage signal is extracted rapidly by constructing a cascaded delayed signal cancellation(CDSC) module. Then the signal is vectorized, and the reference current signal is calculated with the relationship between the instantaneous active power and reactive power and the voltage and current so that the active current and reactive current are controlled independently. In addition, the grid voltage feed-forward is used to further reduce the influence of distortion grid voltage on grid current in order that the voltage balance control of dc-link can be completed accordingly. Compared to the conventional dq control, the time delay from the imaginary current construction can be eliminated by this phase-locked loopless control method. The simulation and experimental results for a three-cell CHB converter are presented to validate the performance of the proposed method under distorted grid voltage conditions.

关 键 词：级联H桥 电网电压畸变 无锁相环 级联延迟信号消除 电网电压前馈 

分 类 号：TM721[电气工程—电力系统及自动化]