为了解决双端电气量测量非同步产生的故障测距误差问题，提出基于故障阻抗计算的非同步故障测距新方法。该方法采用集中参数短线模型，首先利用双端非同步电气量和线路参数计算故障阻抗，然后基于金属性短路故障阻抗的纯电阻性采用共轭法构造出关于故障距离的一元二次方程，最后求解并判别伪根得到真实故障距离。双端量法测距在原理上克服了故障电阻和系统运行方式变化的影响。仿真与数值计算结果表明提出的新方法可靠有效，能消去非同步角的影响，具有良好的测距精度，适用于各种金属性短路故障类型，工程实际应用价值高。%This paper proposes a novel unsynchronized fault location method based on fault impedance computation to solve fault location error problem from two-end unsynchronized measurements of electrical quantities.With lumped parameters model in this method,fault impedance is first computed by both two-end unsynchronized electrical quantities and transmission line parameters.Then a quadratic equation with only unknown fault distance is constructed by conjugate complex method based on purely resistive of metallic short circuit impedance.Finally,the true result is obtained after solving and determining the pseudo-root.Two-end fault location method can overcome effect of fault resistance and system running changes in principle.Simulation results show that this proposed method can eliminate the effect of unsynchronized error with high accuracy in fault location and may be applied in all metallic short circuit fault types with high value practice application in engineering.
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