摘要
LCL型滤波器广泛用于并网逆变器,然而,仅对注入电网电流控制,不能解决由LCL谐振峰值引起的电流谐波和低带宽问题。本文提出了一种并网LCL逆变器的主动阻尼(AD)控制方法,该方法仅基于注入到电网中的电流的反馈,反馈环节采用了一阶高通滤波器加一阶低通滤波器进行选频,从而抑制住谐振峰值。由于拓宽了反馈环节的带宽,此方法适用于电网阻抗引发的谐振频率偏移现象。同时,本文还采用一种带有阻尼的谐波补偿控制策略,并分析该策略对逆变器性能的影响,结果表明它可以有效抑制低频谐波,提高系统电网阻抗变化环境下的稳定性。通过MAT-LAB/Simulink仿真模拟与2kW实验平台验证了所提控制方法的有效性。
LCL filters are widely used in grid-connected inverters. However, the injected grid current control does not solve the problem of current harmonics and low bandwidth caused by the LCL resonance peak. The paper pro- poses an AD control method for LCL inverters, which is only based on the feedback of the grid current. The feed- back loop uses the first-order HPF plus the first-order LPF for frequency selection, thereby suppressing the reso- nance peak. Due to the widening of the bandwidth of the feedback loop, this method is suitable for the resonance frequency shift phenomenon caused by the impedance of the grid. The paper also uses a harmonic compensation control strategy with damping, and analyzes the influence of this strategy on the performance of the inverter. The re- sults show that it can effectively suppress low-frequency harmonics and improve the stability of the system under the impedance change environment. The effectiveness of the proposed control and design has been verified by MAT- LAB / Simulink simulation and 2kW experimental platform.
作者
董密
欧静
杨建
李亚宁
张心露
肖国勋
DONG Mi;OU Jing;YANG Jian;LI Ya-ning;ZHANG Xin-lu;XIAO Guo-xun(School of Automation, Central South University, Changsha 410083, China;Changsha Best Electrical Technology Co. , Ltd. , Changsha 410205, China)
出处
《电工电能新技术》
CSCD
北大核心
2019年第7期1-9,共9页
Advanced Technology of Electrical Engineering and Energy
基金
国家自然科学基金项目(51677194)
工业强基工程项目(0714-EMTC-02-00443)
关键词
单相并网逆变器
LCL谐振
AD控制
谐波补偿
电网电感
single-phase grid-connected inverter
LCL resonance
active damping control
harmonic compensation
grid inductance
