【摘要】 特高压平行双回线路距离保护在单相接地故障时受到两回线路互感和故障电阻的不利影响。针对此问题,提出一种新的平行双回线路距离保护算法。算法的核心思想是利用故障点故障电压和故障点电流同相位的特点,并对故障相的电压、电流以及相邻一回线路的零序电流进行傅里叶变换,通过列方程,求解故障距离。还讨论了新算法在平行双回线路的一回检修或者两回线路分裂运行下的效果。理论分析和PSCAD/EMTDC仿真实验证明,该算法耐过渡电阻能力高,不受两回线路互感和负荷的影响,不会引起平行双回线路距离保护一段误动或拒动。该算法有望构成新型的特高压平行双回线路距离保护。更多还原

【Abstract】 This paper proposes a new algorithm to calculate the fault impedance from the location of distance protection to the fault point on Ultra-high Voltage(UHV) parallel transmission line, considering the influence of mutual coupling and fault resistance. This algorithm is based on the fact that the fault point voltage and fault path current have the same phase angle. The fault distance can be obtained by using Fourier analysis of voltage and current of fault phase, and zerosequence current of adjacent circuit. One of parallel lines in maintenance or in split operation is also discussed. This paper presents the features of the new algorithm and assesses its performance by using PSCAD/EMTDC simulation. The algorithm is expected to constitute a new type of UHV parallel lines distance protection.更多还原