Research on characteristics of voltage fault traveling waves of transmission line

A Line parameters of high voltage transmission lines, especially of EHV/UHV long distance transmission line, have the characteristics of distribution parameters obviously. When a fault is occurred on a transmission line, voltage fault travelling waves and current fault travelling waves generated by fault superimposed voltage source have abundant fault information which can be use as criteria for fault detection. The characteristic analysis of voltage fault travelling waves after a fault occurred on a transmission line concluded that: Voltage fault travelling waves after a fault consist of two components, pre-fault load travelling waves and post-fault fault travelling waves, and fault travelling waves can be classified into fault transient travelling waves and fault steady-state travelling waves according to time period, and fault transient travelling waves contain two characteristics, high-frequency wave-front and power frequency component, and the polarity of high frequency wave-front is the same as the initial polarity of power frequency component. Research on characteristics of voltage transient travelling waves provide an important theoretical basis for the establishment of new direction protection theory based on travelling waves.