METHOD FOR ESTIMATING FAULTS OF POWER TRANSMISSION LINE

摘要

PURPOSE: A method for estimating a fault location of a power transmission line is provided to synchronize time points of fault record data of both ends of the power transmission line, thereby estimating the fault location more accurately. CONSTITUTION: First synchronization of a fault time point is performed with a time point in which changes in a current is larger than a predetermined reference (S104). Second synchronization of the fault time point is performed by correcting a sample distance (S105). Third synchronization of the fault time point is performed by correcting a synchronization error of the sample distance through a mathematical operation (S110). A fault location impedance rate value in each of time points calculated by the second and third synchronization is estimated (S111). A final fault location is estimated by selecting the fault location in a time point in which an impedance error is smaller (S113). [Reference numerals] (AA) Start; (BB) End; (S101) Read fault record data; (S102) Calculate phase voltage, phase current; (S103) Convert into first voltage and current; (S104) First synchronization; (S105) Second synchronization; (S106) Extract first a sine wave (apply DFT); (S107) Apply method of symmertrical coordinates; (S108,S111) Calculate a fault location impedance rate value; (S109,S112) Calculate distance (L), impedance difference (diff), success or failure (success); (S110) Third synchronization; (S113) Check a value having small diff; (S114) Display distance (L), impedance difference (diff), success or failure (success)