摘要
换流器作为连接交直流网络的电气元件,考虑其两侧电压、电流的相互影响是研究其谐波模型的关键。提出一种新型的换流器谐波全耦合模型,该模型基于二端口网络的H参数矩阵定量描述换流器交流侧电流与电压、交流侧电流与直流侧电流、直流侧电压与交流侧电压、直流侧电压与电流之间的耦合关系。通过将开关器件的动作状态分别以对应的开关函数表示,在触发角对称的条件下建立各换流阶段电压电流的数学关系式,并以傅里叶变换求解,推导H参数矩阵。该模型可广泛适用于含复杂背景谐波的交直流系统;当触发角增大到一定程度,可忽略换相重叠角的影响,得到该模型的简化形式,适用于可控换流器触发角较大或系统电抗较小情况。Simulink时域仿真结果验证了所提模型的准确性。
As the converter is an electric component connecting to both AC and DC networks,the interactions among the voltages and currents of two sides are the key factors for the study of its harmonic model. A fully-coupled harmonic model of converter is proposed,which,based on the H parameter matrix of dual-port network,quantificationally describes the coupling relationships between AC-side current and voltage,AC-side current and DC-side current,DC-side voltage and AC-side voltage,DC-side voltage and current. The operating statuses of switching device are expressed respectively by the corresponding switching functions and the mathematical relationships between voltage and current for different conversion stages are established in the condition of symmetric firing angles,which are then solved by Fourier transform to deduce its H parameter matrix. The model is generally applicable to the AC / DC system with complex background harmonics. When the firing angle increases to a certain degree,it can be simplified by ignoring the influence of commutation overlap angle,suitable for the controllable converter with bigger firing angle or smaller system impedance. The accuracy of the proposed model is verified by the results of Simulink time-domain simulation.
出处
《电力自动化设备》
EI
CSCD
北大核心
2016年第2期45-50,共6页
Electric Power Automation Equipment
基金
国家重点基础研究发展计划(973计划)项目(2012-CB215100-G)~~
关键词
换流器
谐波模型
H参数
开关函数
全耦合
傅里叶变换
谐波分析
electric converters
harmonic model
H parameters
switching function
fully-coupled
Fourier transforms
harmonic analysis