CAJ | 학술논문

分析了具备低电压穿越(LVRT)能力的双馈式风电场送出线路故障暂态特性。风电送出线路风场侧保护测得的电压与电流主要频率分量不一致，致使传统的依据工频电压、电流相量的距离保护元件动作性能受到严重影响，无法正常工作。基于输电线路时域模型的解微分方程算法不涉及信号的频域信息，可以克服送出线电压、电流主频不同带来的影响，但受高频分量的影响较大。等传变距离保护相较传统的解微分方程算法，增加了低通滤波及故障点电压重构两个环节，显著改善了算法的测距性能。PSCAD/EMTDC仿真结果表明，线路不同位置处发生不同类型故障时，等传变距离保护算法均可以实现快速、准确测距。
분석료구비저전압천월(LVRT)능력적쌍궤식풍전장송출선로고장잠태특성。풍전송출선로풍장측보호측득적전압여전류주요빈솔분량불일치，치사전통적의거공빈전압、전류상량적거리보호원건동작성능수도엄중영향，무법정상공작。기우수전선로시역모형적해미분방정산법불섭급신호적빈역신식，가이극복송출선전압、전류주빈불동대래적영향，단수고빈분량적영향교대。등전변거리보호상교전통적해미분방정산법，증가료저통려파급고장점전압중구량개배절，현저개선료산법적측거성능。PSCAD/EMTDC방진결과표명，선로불동위치처발생불동류형고장시，등전변거리보호산법균가이실현쾌속、준학측거。
The fault features of outgoing transmission line in DFIG-based wind plant with the capacity of low-voltage ride-through (LVRT) are analyzed. The main frequency inconsistency between voltage and current of wind farm outgoing transmission line leads a serious impact on the action performance of traditional distance protection element based on power frequency voltage and current phasor. The differential equation algorithm based on the time-domain differential equation model of transmission line does not involve the frequency-domain information of the signal, thus it is unaffected by the main frequency inconsistency between voltage and current of wind farm outgoing transmission line. But the high-frequency characteristic of the differential equation algorithm is poor. Compared with the traditional differential equation algorithm, two processes are gained in the equal transfer process-based distance protection, low-pass filtering and re-structuring of the voltage at the fault point, which significantly improves the performance of the algorithm. The PSCAD/EMTDC simulation results show that the distance element which employs the equal transfer process-based distance protection algorithm can trip correctly and quickly while unaffected by the wind power transient voltage and current no matter what kind of fault occurs in the protection scope.