基于等效电流源的级联混合直流馈入系统强度影响分析  

Strength Influence in Cascaded Hybrid DC Feed-in System Based on Equivalent Current Source

作　　者：何遥 张英敏[1] 李保宏[1] 江琴[1] 刘天琪[1] 王洪耀 张婉欣 HE Yao;ZHANG Yingmin;LI Baohong;JIANG Qin;LIU Tianqi;WANG Hongyao;ZHANG Wanxin(College of Electrical Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China)

机构地区：[1]四川大学电气工程学院,四川省成都市610065

出　　处：《电网技术》2024年第3期1244-1252,共9页Power System Technology

基　　金：四川省自然科学基金项目(2022NSFSC0262);中央高校基本科研业务费专项资金(2022SCU12005)。

摘　　要：级联型混合直流系统受端的模块化多电平换流器高压直流系统(modular multilevel converter high voltage direct current,MMC-HVDC)和电网换相换流器高压直流系统(line commutated converter high voltage direct current,LCC-HVDC)会因馈入点电气距离较近而存在强相互作用关系。为明确级联型混合直流馈入系统中MMC-HVDC对LCC-HVDC系统强度的影响,提出考虑幅值和相位的MMC等效电流源的简化等效方法,基于所提MMC等效原理将级联型混合直流馈入系统等效成单馈入LCC-HVDC系统,分析等效单馈入系统的参数计算方法,并提出等效单馈入短路比评估指标。最后通过该指标分析归纳了不同控制方式、不同电气距离下等效单馈入系统的系统强度变化情况,即为MMC-HVDC对LCC-HVDC系统强度的影响规律。机理分析和基于PSCDAD/EMTDC、MATLAB的仿真结果表明,所提等效方法具有有效性且所提指标能很好地反应MMC-HVDC对LCC-HVDC系统强度的影响。The modular multilevel converter high voltage direct current(MMC-HVDC)and the line commutated converter high voltage direct current(LCC-HVDC)of the cascaded hybrid DC receiving end system may have a strong interaction relationship due to their close electrical distance at the feed-in points.In order to clarify the influence of the MMC-HVDC on the strength of the LCC-HVDC system in the cascaded hybrid DC feed-in system,a simplified equivalent method of the MMC equivalent current source considering the amplitude and phase is proposed.Based on the proposed MMC equivalence principle,the cascade hybrid DC feed-in system is equivalent to a single-infeed LCC-HVDC system,the calculation of the parameters of the equivalent single-infeed system is analyzed,and the equivalent single-infeed short circuit ratio evaluation index is proposed.Finally,the variation of the system strength of the equivalent single-infeed system under different electrical distances and different control modes is analyzed and summarized by this index,which is the influence law of the MMC-HVDC on the system strength of the LCC-HVDC.Mechanism analysis and simulation results based on the PSCDAD/EMTDC and the MATLAB show that the proposed equivalent method is effective and the proposed index is able to well reflect the influence of the MMC-HVDC on the system strength of the LCC-HVDC.

关 键 词：级联型混合直流系统 相互作用关系 系统强度 MMC等效电流源 等效单馈入短路比 

分 类 号：TM721[电气工程—电力系统及自动化]