抑制高压直流输电系统换相失败的可控串联电阻  

Controllable Series Resistor for Commutation Failure Mitigation in LCC-HVDC System

作　　者：夏海涛 周小平[1] 陈斌超 邓凌峰 洪乐荣 朱仁龙 XIA Haitao;ZHOU Xiaoping;CHEN Binchao;DENG Lingfeng;HONG Lerong;ZHU Renlong(National Electric Power Conversion and Control Engineering Technology Research Center(Hunan University),Changsha 410082,Hunan Province,China)

机构地区：[1]国家电能变换与控制工程技术研究中心(湖南大学),湖南省长沙市410082

出　　处：《电网技术》2023年第6期2539-2548,共10页Power System Technology

基　　金：国家自然科学联合基金项目(U2166602);长沙市科技计划项目(kq2107005);国家自然科学青年基金项目(51907058)。

摘　　要：针对高压直流输电系统中的换相失败问题,提出一种基于可控串联电阻(controllableseriesresistor,CSR)的解决方案。该方案比已有的换相失败防御模块省去了工频变压器;如果提供的辅助电压幅值相同,则比桥式可控串联电容少二分之一的功率器件。首先,给出了CSR的拓扑及控制。然后,基于准稳态方程分析了CSR的换相失败抑制机理及控制特性。结果表明,交流出线处的串联电阻能提高换相电压幅值并抑制相位超前跃变,从而有利于顺利换相。接着,损耗分析的结果显示,CSR稳态功率损耗仅占额定直流功率的0.045%,对系统正常功率传输的影响很小。最后,基于PSCAD/EMTDC电磁暂态模型的仿真结果验证了所提方案的有效性:CSR的换相失败抑制能力较标准系统提高6~7.2倍,比桥式可控电容提高80%~90%。In order to mitigate the commutation failure(CF)in the line commutated converter based high voltage direct current(LCC-HVDC)system,a solution based on the controllable series resistor(CSR)is proposed in this paper.Compared with the available commutation failure prevention module(CFPM),the proposed solution operates without the power transformer.If the given voltage stress is the same,the CSR needs half less powers semiconductor devices than the bridge type controllable capacitor(BTCC).Firstly,the main circuit structure and control scheme of CSR are presented.Secondly,based on the quasi steady-state equations,the CF mitigating mechanism and control characteristics of CSR are analyzed.The analytical results demonstrate that the series resistor at AC outgoing line can support the commutation voltage amplitude and suppress the phase leading jump,and thus facilitates the commutation process.Then,the loss estimation shows that the steady-state power loss of CSR accounts for only 0.045%of the rated DC power,which has little impact on the normal power transmission of the LCC-HVDC system.Finally,the simulation results based on the CIGRE model in PSCAD/EMTDC verify the effectiveness of the proposed method:the CF mitigation ability of CSR is 6~7.2 times higher than that of the benchmark model,and 80%~90%higher than that of BTCC.

关 键 词：高压直流输电 换相失败 可控串联电阻 

分 类 号：TM721[电气工程—电力系统及自动化]