摘要
为解决单相接地永久性故障判别灵敏度不足的问题,提出采用并联电抗器零模电流不同频率分量比值特征的三相自适应重合闸故障性质判别方法。通过分析单相接地故障时的并联电抗器零模电流,发现不同故障性质情况下其自由振荡频率不同,据此建立了包含衰减非周期分量及不同自由振荡频率分量的并联电抗器零模电流识别模型。当输电线路发生故障且两侧断路器跳开后,将并联电抗器零模电流作为已知量,利用最小二乘拟合算法求取其不同频率分量的幅值,根据各频率分量电流幅值对比关系实现永久性故障判别。EMTP仿真表明,该方法适用于单端及双端带并联电抗器线路,且不受过渡电阻、故障位置的影响,灵敏度高。
To heighten sensitivity of permanent fault identification for single-phase-to-ground fault, a three-phase adaptive reclosure in transmission lines with shunt reactors is developed. It is found that the shunt reactor zero modal current gets with different free oscillation frequencies in transient fault or permanent fault fin the case of single-phase-to-ground. An identification model of shunt reactor zero-modal current is established, which includes decaying DC component and two frequency components corresponding to transient fault and permanent fault. Once the single- phase-to-ground fault occurs and circuit breakers open, each frequency component is obtained by least square fitting, where shunt reactor zero-modal current is available. The amplitudes of various frequency components are adopted to distinguish the permanent faults from transient faults. EMTP simulation shows that the proposed scheme is of higher sensitivity and freedom from the influences of transient resistance and fault position in permanent faults identification for transmission lines with shunt reactors.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2013年第6期85-89,96,共6页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金重点资助项目(51037005)
