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针对过往电网换相换流器高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)交直流系统的强度指标缺乏严密理论基础的问题,该文研究计及LCC-HVDC交直流系统静态电压稳定的强度指标定义方法.首先,定量分析单馈入LCC-HVDC系统不同控制方式对交直流系统静态电压稳定的影响.其次,提出一种能够衡量交直流系统电压稳定裕度的综合短路比(integrated short circuit ratio,ISCR)强度指标.该指标考虑了交直流系统的实际潮流信息,能够同时应用于交直流系统的规划、设计和运行阶段;兼顾了LCC-HVDC系统的直流功率-电压动态特性,能够研究控制方式差异性对其影响;同时,基于静态电压稳定极限定义的临界综合短路比(critical integrated short circuit ratio,CISCR)指标取值恒为1,因而能够刻画互联交流电网对直流系统的临界电压支撑强度.最后,考虑额定运行工况和负荷动态变化过程的算例分析结果,及不同强度指标的对比分析,均表明了采用ISCR和CISCR指标的有效性.“,”Taking cognizance of the issue of lacking in rigorous theoretical background encountered by previous strength indices of the LCC-HVDC AC/DC system,the method for the definition of the strength index is studied based on the static voltage stability.Firstly,a quantitative assessment of the influence of the different control modes on the static voltage stability of the single-infeed LCC-HVDC AC/DC system is conducted.Then,an integrated short circuit ratio (ISCR) index is proposed to assess the system strength and its voltage stability margin.With the actual power flow information and DC power-voltage dynamic characteristics included,the index can be employed in all stages of planning,design and operation,and to study the influence of the different control modes on itself.Meanwhile,a critical integrated short circuit ratio (CISCR) index defined based on the static voltage stability limit is introduced to depict the critical voltage support strength.Furthermore,the proposed indices are validated by case studies and by comparison with other indices.