Studies On Novel Fault Location Methods For Transmission Line With Two-end Unsynchronized Measurements

Although PMU (phase measurement unit) devices can offer synchronized data inprinciple, synchronization problems were exist in two-end fault location method, but takeneconomy into account, not all the buses, power plants and substations in the entire networksare equipped with PMU devices, the unsynchronized measurement problem was inevitable.Location preciseness will be affected by two-end unsynchronized measurement error problemcaused by bus PMU failure or loss of two-end fault location method for transmission line. Inorder to obtain highly accurate and eliminate the unsynchronized error problem, This paperproposed eight novel fault location methods to eliminate unsynchronized angle in principlewith two-end unsynchronized measurement, using sequence component or conjugate complexmethods to construct easily solved location equation separately on both short lumpedparameters transmission line and long distributed parameters transmission line.As two-end unsynchronized electrical data measured, four novel fault location methodswith two-end unsynchronized measurements were proposed in proper order, the methodsusing idea of constructing equation through sequence component or conjugate complexmethods to solve the equation using equal voltage principle at fault point with both faultdistance and unsynchronized angle as the unknown. Further more, other four novel faultlocation methods with two-end unsynchronized measurements were proposed in proper order,the methods using conjugate complex method based on based on pure resistance form of faultimpedance or sequence component method based on plural form of fault impedance to solvethe equation by deducing the fault impedance expression by two-end electrical data toeliminate unsynchronized angle in the process with both fault distance and unsynchronizedangle as the unknown.Simulation and numerical calculation results show that eight reliable and valid locationmethods can basely eliminate the effect of unsynchronized error with high accuracy in faultlocation and good value practice application in engineering.