混合多端直流输电系统直流侧阻抗建模及谐振抑制  

DC-Side Impedance Modeling and Resonance Suppression of H-MTDC Transmissson System

作　　者：宁联辉[1] 吴再驰 侯凯 康小宁[1] 张海涛[1] 杨彩虹 NING Lianhui;WU Zaichi;HOU Kai;KANG Xiaoning;ZHANG Haitao;YANG Caihong(School of Electrical Engineering,Xi'an Jiaotong University,Xi’an 710049,China;NARI Group Corporation,State Grid Electric Power Research Institute,Nanjing 211106,China;NARI-TECH Nanjing Control Systems Co.,Ltd.,Nanjing 211106,China)

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]南瑞集团有限公司(国网电力科学研究院有限公司),南京211106 [3]国电南瑞南京控制系统有限公司,南京211106

出　　处：《南方电网技术》2023年第8期48-57,共10页Southern Power System Technology

基　　金：国网电力科学研究院有限公司科技项目(SGNR0000KJJS2000649)。

摘　　要：混合多端直流(hybrid multi-terminal HVDC,H-MTDC)输电系统直流场设备的自然等效电阻较小,在控制系统无法提供足够大阻尼的情况下易导致系统直流侧的谐振振荡。首先推导了换相换流站(line commuted converter,LCC)和模块化多电平换流站(modular multilevel converter,MMC)直流侧输出阻抗,在MATLAB中建立了H-MTDC系统的阻抗模型并给出了基于环路增益的稳定判据。其次,通过计算环路增益对各控制参数的频域灵敏度定量地分析了参数变化对环路增益曲线的影响,明确了影响系统谐振特性的主导因素,并结合稳定判据制定了参数调整方案。再次,通过反馈换流站输出的直流电流,将LCC站原定直流电流控制器改进为电流阻尼控制器并设计了控制器参数。最后,通过PSCAD/EMTDC时域仿真验证了所提谐振抑制策略的有效性。The natural equivalent resistance of the DC yard equipment in hybrid multi-terminal HVDC(H-MTDC)system is small,so it is easy to cause resonance oscillation at the DC side of the system when the control system can't provide sufficient damping.This paper firstly deduces the DC-side output impedances of line commuted converter(LCC)and modular multilevel converter(MMC)sta⁃tions.The impedance model of H-MTDC system is established in MATLAB and the stability criterion based on loop gain is given.Secondly,by quantitative analysis of the frequency domain sensitivity of controller parameters through calculating loop gain,their ef⁃fect on loop gain curve has been quantitatively analyzed.The dominant factors affecting the resonance characteristics of the system are clarified,and a parameter adjustment scheme is formulated combining stability criteria.Thirdly,by feeding back the DC current from the converter station,the original constant current controller of LCC station is improved to a current damping controller and its parameters are designed.Finally,the effectiveness of the resonance suppression strategies are verified by time domain simulation in PSCAD/EMTDC.

关 键 词：混合多端直流 阻抗建模 谐振抑制 环路增益 频域灵敏度 电流阻尼控制 

分 类 号：TM732[电气工程—电力系统及自动化]