CAJ | 학술논문

为了准确评估混合双馈入直流系统中电网换相换流器高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)子系统的受端系统强度,对LCC-HVDC 子系统的有效短路比进行研究。第一,基于牛顿最优潮流算法,分析混合双馈入直流系统中电压源换流器高压直流输电(voltage source converter based HVDC, VSC-HVDC)子系统采用不同的功率输送方向和控制方式时,对LCC-HVDC子系统的交流系统电压支撑强度的影响关系。第二,计算VSC-HVDC子系统的等效阻抗,提出能够有效评估混合双馈入系统中LCC-HVDC子系统有效短路比的等值有效短路比指标。利用该指标可将混合双馈入直流系统中LCC-HVDC子系统等效为受端交流系统电压支撑强度与之相同的单馈入直流输电系统。最后,基于 PSCAD/ EMTDC进行仿真分析,仿真结果证明了VSC-HVDC对LCC-HVDC 子系统影响关系的正确性以及等值有效短路比指标的有效性。
위료준학평고혼합쌍궤입직류계통중전망환상환류기고압직류수전(line commutated converter based high voltage direct current,LCC-HVDC)자계통적수단계통강도,대LCC-HVDC 자계통적유효단로비진행연구。제일,기우우돈최우조류산법,분석혼합쌍궤입직류계통중전압원환류기고압직류수전(voltage source converter based HVDC, VSC-HVDC)자계통채용불동적공솔수송방향화공제방식시,대LCC-HVDC자계통적교류계통전압지탱강도적영향관계。제이,계산VSC-HVDC자계통적등효조항,제출능구유효평고혼합쌍궤입계통중LCC-HVDC자계통유효단로비적등치유효단로비지표。이용해지표가장혼합쌍궤입직류계통중LCC-HVDC자계통등효위수단교류계통전압지탱강도여지상동적단궤입직류수전계통。최후,기우 PSCAD/ EMTDC진행방진분석,방진결과증명료VSC-HVDC대LCC-HVDC 자계통영향관계적정학성이급등치유효단로비지표적유효성。
The effective short circuit ratio of line commutated converter based high voltage direct current (LCC-HVDC) sub-system in dual-infeed hybrid HVDC system was investigated to evaluate the system strength of LCC-HVDC. Firstly, the voltage support strength of AC system was analyzed when different power flow directions and different controled strategies were adopted in voltage source converter (VSC) based on optimal power flow by Newton approach. Secondly, the equivalent impedance of VSC-HVDC was calculated, and the effective short circuit ratio of the LCC-HVDC was quantified by a proposed “equivalent effective short circuit ratio” index. The LCC-HVDC in dual-infeed hybrid HVDC system could be equivalent to a single-infeed HVDC system which had the same voltage support strength by the index. Simulation results in PSCAD/EMTDC show that the analysis on the effects of VSC-HVDC to LCC-HVDC proved to be accurate and the “equivalent effective short circuit ratio” index is effective.