【摘要】 谐振接地系统发生单相接地故障时,由于故障电流小及接地点电弧不稳定等原因,其零序故障电流准确获取和定值整定困难,使其故障线路的检出仍是难题。提出一种基于暂态能量的故障选线自适应方法,利用所有健全线路暂态能量与故障线路暂态能量之差为最小值的原理,构成故障选线算法。新方法不仅能消除故障电流小和接地点电弧不稳定的影响,还能在短线故障时,克服健全长线电容电流的影响,有很强的抗干扰能力,无需整定也不涉及极性和方向的判断,具有自适应性,可大大改善保护对故障线路检出性能。大量的数字仿真结果表明了该方法的有效性。更多还原

【Abstract】 Due to small grounding current and unstable electric arc at fault position, it is difficult to obtain the zero-current of fault circuit and to tune the parameters of equipments in a small current grounding system with arc suppression coils. Hence the fault circuit selection in this system has always been a complex and difficult problem. This paper presents an adaptive fault circuit selection method based on the principle that the difference of transient energy of normal circuits and that of fault circuit is minimal. The proposed method can erase the influence of small fault current and unstable electric arc. With great adaptability to various faults happened in the system with arc suppression coils and considerable immunity to noises and no requirements of pre-setting, the overall performance of the protection has been upgraded by using the proposed algorithm. Large amount of digital simulation results show that the proposed method is effective and reliable.更多还原