What are the characteristics of the zero sequence direction component?

(2) The action behavior of the zero-sequence directional component is independent of the load and is independent of the magnitude of the transition resistance.

(3) The system will not malfunction when it oscillates.When the zero-sequence directional component is not fully phase-operated on both sides of the line, the zero-sequence positive-direction component acts when the busbar TV is used, and the reverse-direction component does not move; when the sampling line Tv, the action behavior of the zero-sequence directional component is related to the system parameter, zeroThe positive direction component may or may not operate.Then the positive direction element does not operate, and the reverse direction element operates.

(5) As long as the zero-sequence voltage is compensated on the line with the series compensation capacitor, the zero-sequence direction component can correctly judge the short-circuit direction.

(6) Zero-sequence directional components can only protect against ground faults, and are incapable of two-phase ungrounded short-circuit and three-phase short-circuit.The zero-sequence current of the line has a longitudinal electromotive force generated on the other non-faulty line. It is possible that the zero-sequence directional elements at both ends of the non-faulty line are judged to be short-circuited in the positive direction, and the longitudinal zero-sequence direction of the non-faulty line is caused.Protection is wrong.