Double-channel data transmission method in optical fiber longitudinal differential protection

Abstract

The invention relates to a double-channel data transmitting method in optical fiber differential protection. The method is characterized in that: when only one channel is functioning, a protection device carries out synchronous adjustment at the time of sampling according to the data of the functioning channel; when two channels are functioning and power is on, the channel (confirmed for 3 times) with less time delay is preferably chosen as the synchronous adjustment channel; when the two channels are functioning and the time delay of the two channels only differs a little (less than 0.6ms), the channel A is chosen as the synchronous adjustment channel; when the synchronous adjustment channel is disabled, the other normal functioning channel is chosen as the synchronous adjustment channel. When the time delay of the synchronous channel is larger than the time delay of the other channel (the difference is lager than 0.3ms) and the difference continues for 10s, the other channel is chosen as the synchronous adjustment channel.

Description

technical field [0001] The invention relates to the electrical field, in particular to a method for increasing the reliability of longitudinal differential protection through dual channels in optical fiber differential protection of high-voltage power grids. Background technique [0002] Current differential protection of transmission lines needs to transmit a large amount of data information from one side of the line to the other. When a transmission error occurs, it is difficult to reconstruct the information due to the real-time protection requirements and the limitation of channel capacity. This means that if one or more bit errors occur in a frame of hundreds of bits of information, the entire frame of information will be discarded. If the frequency of error codes is not high, it will have little impact on the protection performance, but if the frequency of errors is high, the differential protection will be blocked. If there is one bit error or multiple bit errors in ...

AI Technical Summary

Problems solved by technology

[0005] The above methods have the following disadvantages: First, the switching time is long. It takes a long time from the failure of the main channel to the protection using the backup channel to establish a new data connection, so the channel switching takes a long time for the main protection to exit

The second is that the data quality of the channel transmission has not improved much. The reason is that when the communication quality of the main channel decreases and the switching threshold is not reached, the main channel is still used for data communication, and the protection data is greatly affected by intermittent bit errors.

Images