中文摘要：

理论上讲，输电线路单位长度的电阻、电感、电容以及输电线路的实际长度等参数都是无法精确获得的。这些参数受多种因素的影响，其工程中的实测值只能是近似的。在双端故障定位时，线路设定参数和实际参数的偏差将影响定位的精度。文中通过对双回线故障定位函数的推导，得出线路参数的设定偏差对故障定位精度的影响机理，并给出了线路参数偏离真实值的情况下提高故障定位精度的措施。仿真结果证明了结论的正确性。

英文摘要：

Theoretically, the resistance, inductance and capacitance in per unit length, and the effective length of transmission line cannot be obtained accurately. Influenced by many factors, these parameters acquired by practically measurement are only the approximate values. To two-terminal fault location, the parameter deviation of the settings from actual values will have an adverse influence on the accuracy of fault location. By deducing the fault location function of parallel transmission lines, the mechanism that parameter deviations influence the locating accuracy is achieved. In the paper, the improving measures are also given to locate faults in the situation of parameter deviation. Simulations show the validity of the proposed methods.