Grounding fault distance protecting method of double circuit lines on same tower

Abstract

The invention discloses a grounding fault distance protecting method of double circuit lines on the same tower. The grounding fault distance protecting method of the double circuit lines on the same tower comprises the steps of estimating the phase of voltages of a grounding fault point by using a fault syntropy zero sequence current phase, directly calculating a fault distance x according to the fact that the voltage drop of a protecting mounting portion to the grounding fault point is in linear relation with the fault distance, and comparing the size relationship of the fault distance x and a protection setting range xset. If a I circuit line of the double circuit lines on the same tower is in single-phase grounding fault, and the fault distance x is smaller than the protection setting range xset, the I circuit line of the double circuit lines on the same tower is protected to send an action tripping signal. If a II circuit line of the double circuit lines on the same tower is in single-phase grounding fault, and the fault distance x is smaller than the protection setting range xset, the II circuit line of the double circuit lines on the same tower is protected to send the action tripping signal. According to the grounding fault distance protecting method of the double circuit lines on the same tower, a symmetrical component method and a six-sequence component method are used comprehensively, and accurate measuring of the fault distance of the single-phase grounding fault of the single circuit line of the double circuit lines on the same tower is achieved.

Description

technical field [0001] The invention relates to the technical field of relay protection of electric power systems, in particular to a grounding fault distance protection method for parallel double-circuit lines on the same pole. Background technique [0002] The additional impedance generated by the transition resistance will seriously affect the action performance of the ground fault distance protection of parallel double-circuit lines on the same pole. If the additional impedance generated by the transition resistance is resistive and inductive, it is easy to cause the ground fault distance protection to refuse to operate when the ground fault occurs in the protection zone; . [0003] The existence of capacitance to ground and zero-sequence mutual inductance between double-circuit lines paralleled on the same pole has a great impact on the zero-sequence compensation coefficient, which in turn affects the protection range of the ground fault distance protection, which is l...

AI Technical Summary

Problems solved by technology

[0002] The additional impedance generated by the transition resistance will seriously affect the action performance of the ground fault distance protection of parallel double-circuit lines on the same pole

If the additional impedance generated by the transition resistance is resistive and inductive, it is easy to cause the ground fault distance protection to refuse to operate when the ground fault occurs in the protection zone;

[0003] The existence of capacitance to ground and zero-sequence mutual inductance between double-circuit lines paralleled on the same pole has a great impact on the zero-sequence compensation coefficient, which in turn affects the protection range of the ground fault distance protection, which is likely to cause protection refusal or out-of-range errors. verb: move

Therefore, the existing ground fault distance protection for parallel double-circuit lines on the same pole cannot meet the requirements of the power grid

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