Pilot protection method for direct-current transmission line and application of pilot protection method

A technology for DC transmission line and longitudinal protection, applied in emergency protection circuit devices, electrical components, power transmission AC network, etc., can solve the problem of long delay of DC line backup protection action, and improve safety, stability, and action speed. Lifting, Criterion Simple Effects

CN114204525AActive Publication Date: 2022-03-18HUAZHONG UNIV OF SCI & TECH
9 Cites 1 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-03-18

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention belongs to the field of power system relay protection, and particularly relates to a direct-current transmission line pilot protection method and application thereof, and the method comprises the steps: collecting and filtering voltage and current, and calculating the comprehensive admittance of a single-pole line if the single-pole line is the single-pole line; if the line is a bipolar line, calculating differential current of a positive line and a negative line and an integral value of the differential current in a current time window for fault pole selection, and calculating voltage common modulus and voltage differential modulus of a rectification side and an inversion side to calculate common-mode comprehensive admittance and differential-mode comprehensive admittance; fault area judgment is carried out by using a criterion based on unipolar line comprehensive admittance; or, if the pole selection result is single-pole grounding, the criterion based on common-mode comprehensive admittance is adopted for fault area judgment, and if the pole selection result is inter-pole short circuit, the criterion based on differential-mode comprehensive admittance is adopted for fault area judgment. According to the method, the criterion is simple, the transition resistance resistance is high, no line parameter is needed, and compared with a traditional current differential protection non-locking process, the action speed of line backup protection can be effectively improved.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention belongs to the field of relay protection of electric power systems, and more specifically relates to a method for longitudinal protection of direct current transmission lines and its application. Background technique

[0002] The DC transmission system has the advantages of long transmission distance, large transmission capacity, flexible control, and asynchronous networking between AC systems, and has been widely used in the world. The transmission distance of HVDC transmission lines is long, and the probability of failure is high. As an indispensable part of the protection system of HVDC transmission projects, DC line protection undertakes the major task of quickly detecting and clearing line faults, and its performance directly affects the entire DC Operational performance of transmission projects.

[0003] The current DC transmission line protection usually adopts the protection schemes of ABB and SIEMENS. Among them, the traveling ...

Examples

Embodiment Construction

[0036] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

[0037] The following embodiments take a typical bipolar direct current transmission system as an example for illustration, as figure 1As shown, a typical bipolar DC transmission system includes rectification side AC equivalent power supply 1, rectification side AC line 2, rectification side AC busbar 3, positive rectification side converter transformer 4, positive rectification side converter st...