CAJ | 학술논문

随着大容量高压直流逐步投运，电网进一步呈现“强直弱交”特性，多送出特高压直流系统对互联电网稳定性的影响逐渐突显。分析了送端故障引发直流功率瞬降特性，以三区域交直流等值模型为基础，分析了不同功率流向情况下多回直流功率瞬降对送端系统稳定性的影响，并与单回直流闭锁故障进行了对比分析，最后采用“三华”实际电网算例进行了验证。结果表明，多回直流功率瞬降导致的送端系统失稳模式为第一摆/第二摆功角失稳，对送端系统稳定性的影响严重程度接近单回直流闭锁故障，需要进一步深入研究有效的应对措施。
수착대용량고압직류축보투운，전망진일보정현“강직약교”특성，다송출특고압직류계통대호련전망은정성적영향축점돌현。분석료송단고장인발직류공솔순강특성，이삼구역교직류등치모형위기출，분석료불동공솔류향정황하다회직류공솔순강대송단계통은정성적영향，병여단회직류폐쇄고장진행료대비분석，최후채용“삼화”실제전망산례진행료험증。결과표명，다회직류공솔순강도치적송단계통실은모식위제일파/제이파공각실은，대송단계통은정성적영향엄중정도접근단회직류폐쇄고장，수요진일보심입연구유효적응대조시。
With gradual launching of large capacity high-voltage direct current (HVDC) projects,the characteristic of “strong DC and weak AC" of the power grid is becoming increasingly conspicuous.The influence of the multiple ultra-high-voltage direct current(UHVDC) sending system on the stability of the interconnected power system is apparent.The HVDC power drop characteristic caused by contingencies of the sending-side system is analyzed and,on the basis of the three-region AC/DC equivalent model,the impact of the multiple HVDC power drop on the stability of the interconnected system in different power flow directions is accounted for,and the single HVDC blocking is used for comparison.Finally,verification is made using the“North China-Central China-East China"power grid case studies.The results show that the instability mode of the sending-side system caused by the multiple HVDC power drop is the first/second angle instability,the severity of the impact of which on the sending-side system stability is close to that of the single HVDC blocking,and further study of effective countermeasures is necessary.