Method for carrying out seamless handover between longitudinal differential protection and pilot protection under single channel

Abstract

The invention relates to a method for carrying out seamless handover between longitudinal differential protection and pilot protection under a single channel, comprising the following steps of: integrating pilot information at the most front end of a differential frame and adding an application layer CRC (Cyclic Redundancy Check) code to the pilot information integrated differential frame at the application layer and transmitting the check code as one part of an HDLC (High-level Data Link Control) frame; forming the HDLC frame by adding the pilot information, the longitudinal information application layer CRC code and horizontal information and automatically generating a link layer CRC code in a link layer and transmitting the check code together with the HDLC frame. The invention has thebeneficial effect of taking full advantage of the characteristics of longitudinal protection, such as low requirements on channels, strong tolerance to error codes, support of one-way operational manner, adaptation to unsymmetrical two-way channel time delay and the like.

Description

technical field [0001] The invention relates to the longitudinal difference and longitudinal protection of electric system lines, in particular to a method for automatically realizing seamless switching between longitudinal difference protection and longitudinal protection in a single protection device according to the channel condition under the condition of single channel. Background technique [0002] Line differential protection has simple principle, fast action speed, high sensitivity, natural phase selection ability, and is not affected by system oscillation, weak feed and other operating modes. With the development of power system communication network, line differential protection has become a high-voltage protection system. The first choice for line main protection. For the point-to-point dedicated optical fiber communication mode, since the two cores of receiving and transmitting are often in the same optical fiber, and there is no photoelectric conversion link in ...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to solve how to establish an effective switching method under the condition that the differential protection and the longitudinal protection share a channel, so as to ensure that the advantages of the principle of the longitudinal differential protection can be brought into play, and the requirements of the longitudinal protection on the channel can be utilized. Low, small amount of longitudinal information, and strong tolerance to channel bit errors; solve the problem that the longitudinal difference protection device cannot monitor the bidirectional delay consistency of the channel, and realize the optical fiber self-healing ring network channel switch when the round-trip routing delay is inconsistent Automatic switching between longitudinal differential protection and longitudinal protection

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