Used the six-sequence fault component,the action of some phase selectors,including the phase current difference suddenly-change and the sequence current were analyzed in this paper.

By using the six-sequence fault component,this paper investigates the amplitude and phasor characteristics of fault component current for cross faults of double lines with their phasor comparison equations presented.

directional comparison pilot protection for six-phase transmission lines is presented based on the above mentioned three fault sequence components.

But a large number of literatures on this subject mostly discuss the concept related to fault components from the view of application,like Power-frequency Variation,break variable,positive sequence fault components,fault-generated transients,etc.

Then it calculates the positive sequence fault components in accordance with the fault boundary condition.

The concept and features of positive sequence fault components are introduced according to superposition principle.

In order to utilize right-of-way efficiently of six-phase transmission lines,the characteristics of fault current sequence component on six-phase transmission lines were analyzed.