基于调制理论的高压直流输电系统混合谐振型谐波不稳定判据

发布时间：2018-07-02 19:26

本文选题：高压直流 + 输电系统　；参考：《高电压技术》2014年05期

【摘要】：高压直流输电系统中交流侧二次谐波分量和直流侧基波分量经换流器调制后形成混合谐振,会诱发谐波不稳定。为快速判断混合谐振型谐波不稳定是否发生,在等间隔脉冲触发方式下,将换流器视为二端口网络,并通过开关函数的调制原理推导出了描述换流器的H矩阵。H矩阵可将换流器连接的交直流系统等效为1个RLC电路,从而计算出系统的谐振衰减因子。通过计算得到了谐振衰减因子与换流器的触发角和换相角、换流变的变比和漏抗、交流侧二次谐波阻抗、直流侧基波阻抗之间的关系,给出了判断混合谐振型谐波不稳定的可靠判据。最后在PSCAD/EMTDC中建立仿真模型验证了该谐波不稳定判据的有效性,并验证了可以通过修改相关系统元件参数来避免谐波不稳定现象的发生。
[Abstract]:In HVDC transmission system, the second harmonic component of AC side and the fundamental component of DC side are modulated by converter to form mixed resonance, which will induce harmonic instability. In order to quickly judge whether the harmonic instability of hybrid resonance type occurs or not, the converter is regarded as a two-port network under the equal interval pulse trigger mode. Based on the modulation principle of switching function, the H matrix. H matrix which describes the converter can equivalent the AC / DC system connected with the converter to an RLC circuit, thus the resonant attenuation factor of the system can be calculated. The relationship between the resonant attenuation factor and the trigger angle and phase change angle of converter, the variable ratio and leakage reactance of rheology, the second harmonic impedance of AC side and the fundamental impedance of DC side are obtained. A reliable criterion for judging harmonic instability of hybrid resonance is presented. Finally, a simulation model is established in PSCAD / EMTDC to verify the validity of the harmonic instability criterion, and it is proved that the harmonic instability can be avoided by modifying the parameters of the system components.
【作者单位】：武汉大学电气工程学院;湖北工业大学电气与电子工程学院;
【基金】：国家自然科学基金(51307127)~~
【分类号】：TM721.1

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