CAJ | 학술논문

交直流互联系统换相失败时引起的电磁暂态过程与纯交流环境时不同，因而会对距离保护的动作性能产生影响。以交流系统单相接地故障引发换相失败为例，将换相失败等效为双故障源模型，详细分析了换相失败对接地距离继电器的影响。分析结果表明传统的傅氏算法在换相失败时不能很好地准确测量短路电抗值。然后定义了混联系统中交流保护风险因子的概念及其表达式，并进一步地从风险因子和算法两方面提出了相应的解决措施。最后通过 PSCAD/EMTDC 仿真验证了结论的准确性，并对几种可能的解决措施进行了比较，比较结果表明解微分方程算法在换相失败时性能更好。
교직류호련계통환상실패시인기적전자잠태과정여순교류배경시불동，인이회대거리보호적동작성능산생영향。이교류계통단상접지고장인발환상실패위례，장환상실패등효위쌍고장원모형，상세분석료환상실패대접지거리계전기적영향。분석결과표명전통적부씨산법재환상실패시불능흔호지준학측량단로전항치。연후정의료혼련계통중교류보호풍험인자적개념급기표체식，병진일보지종풍험인자화산법량방면제출료상응적해결조시。최후통과 PSCAD/EMTDC 방진험증료결론적준학성，병대궤충가능적해결조시진행료비교，비교결과표명해미분방정산법재환상실패시성능경호。
The transient process caused by commutation failure in AC-DC interconnected system is not the same as that in pure AC system, which has effect on the performance of distance protection. This paper takes single-phase earth fault as an example to analyze the effect of commutation failure on ground distance relay based on double fault sources model. Analysis results show that the calculated short circuit reactance is not accurate by using Fourier algorithm during commutation failure. Then, AC risk factor is defined and its expression is also provided. Then, the countermeasures are put forward based on AC risk factor and protection algorithm. At last, a large amount of simulation results using PSCAD/EMTDC prove the conclusion to be reasonable and the countermeasures are compared. The comparison results show that differential equation algorithm has better performance in commutation failure environment.