Two-terminal Fault Location Study Based On Double Circuit Line On The Same Pole Dynamic Phasor Model

Because the accurate fault location for high voltage transmission line plays an increasing important role in power system. It becomes a research hotspot of many academicians.Because the double circuit line on the same pole (DLSP) requires narrow corridors, the transmission ability is strong, and investment is saved. Thereby, it is used by line system more and more. Research of fault location for the DLSP has very practical meaning.Firstly, in this thesis, the characteristics of coupled DLSP have been researched, three decouple methods of the DLSP have been discussed: symmetrical component method, six-sequence symmetrical component method, and phase-model transformation method. Symmetrical component method and six-sequence symmetrical component method only can be used where the parameters of the DLSP are symmetrical, but the actual parameter are unsymmetrical. In this thesis phase-model transformation method has been used to decouple the DLST.Secondly, two classical models of distributed parameter DLSP: power frequency model and time-domain model. Based on these two models dynamic phasor model has been deduced. Short circuit fault simulation has been studied according to time-domain model and dynamic phasor model. Dynamic phasor model has been proved to be correct through result of simulation and the speed of convergence is faster than time-domain model.Finally, two-terminal fault location has been constructed based on dynamic phasor model. Simulation result shows the method has high accuracy, which is almost not affected by the type of fault, transition resistance, system parameters.