Study Of New Algorithm For Locating Fault On HV Transmission Lines

Subject about estimating fault location on HV transmission line has been a subject of interest to power system protection researchers and engineers for many years. The majority of work on this subject to be reported as follows:First, a practical fault location technique for HV transmission line using one terminal voltage and current phasors that exist before the fault, and present during the fault (but before the operation of any circuit breakers) is described. This new technique locates fault on transmission line including two-terminal single-circuit line and the line in circle network. In the main, the fault location accuracy of the proposed technique is independent of the remote-end infeeds and shunt capacitance current.Secondly, a new approach to locating fault on transmission line which has two terminals or three terminals(i.e. T-connection line), using synchronized sampling. This new technique can be extremely fast, selective and accurate, providing fault location performance that cannot easily be matched by other known techniques.Thirdly, this paper present a new fault location method using unsynchronized data at two terminals according to equivalent model of series capacitor for transmission lines series capacitor. This location method is the same as that for transmission lines without series capacitor considering the voltage drop across series capacitor, and the only difference consist in distinguishing real and false roots. The real and false roots are distinguished according to whether the difference of fault voltage calculated from terminals is equal to zero or not.The thesis gives the detailed theoretical development of these fault location algorithms, together with extensive numerical performances of locating fault. The proposed techniques are first tested using data obtained from a steady state analysis program, then are tested using data generated by a fault-transient computation program.