摘要
LCL型变流器多模块并联并网运行时系统网络阻抗及谐振特性会发生变化,这将无法保证变流器输出电流的控制特性。对输出电流谐振问题进行定量分析及谐振抑制方法研究非常关键。通过建立多变流器并联并网系统的诺顿等效电路模型,对谐振峰分布进行定量分析,进而在简化模型的基础上,得到了谐振频率的数学表达式。基于电容器并联虚拟电阻的阻尼方法,研究虚拟电阻取值对输出电流的影响,提出了虚拟电阻最优值的计算方法。该方法可保证多变流器并联并网系统输出电流对指令值的跟踪特性。仿真和实验结果证明了定量分析结果的准确性及虚拟电阻取值方法的有效性,实现了对输出电流的有效控制。
The system network impedance and resonant characteristics change when several LCL converters are parallel connected. And it will affect the output current control effect. So quantitative analysis of the output current resonance and research of harmonic suppression methods have important practical significance. This paper devel^oped the Norton＇s equivalent circuit of the multi-paralleled converter system to analyze the distribution law of the resonance frequency. Then the mathematical expression of the resonance frequency was obtained by the simplified model. The influence on the output current by different virtual resistor values was studied. And the calculation method of the optimal virtual resistance value was proposed to ensure the output current following the reference. Simulation and experimental results are provided to validate the accuracy of the quantitative analysis and effectiveness of the virtual resistor value calculation method.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第5期1467-1477,共11页
Proceedings of the CSEE
基金
国家自然科学基金项目(51207126)
新世纪优秀人才支持计划资助(NCET-12-0450)~~
关键词
多变流器并联
LCL滤波器
电流控制
谐振分析
虚拟电阻抑制
multi-paralleled Converters
LCL filter
current control
resonance analysis
virtual resistor damping
