Optical fiber longitudinal difference protection device and synchronous communication method thereof

Abstract

The invention discloses an optical fiber longitudinal difference protection device and a synchronous communication method thereof, which relate to the technical field of communication and aim at solving the technical problems of reducing hardware cost and simplifying software design. The device comprises a CPU (central processing unit) and an FPGA (field-programmable gate array), wherein a signal modulation module, a signal demodulation module, a sending FIFO (first-in first-out) module, a receiving FIFO module, a data frame encoding module, a data frame decoding module, a parallel-serial conversion module and a serial-parallel conversion module are built in the FPGA, wherein the input end of the sending FIFO module and the output end of the receiving FIFO module are connected with a parallel communication port of the CPU respectively; the output end of the sending FIFO module is sequentially connected with the data frame encoding module and the parallel-serial conversion module to the input end of the signal modulation module; and the output end of the signal demodulation module is sequentially connected with the serial-parallel conversion module and the data frame decoding module to the input end of the receiving FIFO module. The device has a low hardware cost and simple software design.

Description

technical field [0001] The invention relates to communication technology, in particular to a technology of an optical fiber differential protection device and a synchronous communication method thereof. Background technique [0002] Relay protection is an important guarantee for the safe and stable operation of power systems, and the development of optical fiber communication technology has made optical fibers more and more widely used in relay protection. The current longitudinal difference protection with optical fiber as the medium cannot be compared with other protection forms The various advantages are receiving more and more attention and popularization and application. [0003] The optical fiber longitudinal differential protection of the power system is achieved by two protective devices at different positions exchanging data through optical fiber communication and realizing synchronous sampling to achieve longitudinal differential protection. Synchronous communicati...

AI Technical Summary

Problems solved by technology

The method of synchronous serial chip plus FPGA used in the existing optical fiber vertical difference protection device has the defect of high hardware cost, and the synchronous serial chip encodes data according to the HDLC protocol, and the HDLC protocol flag must be used when encoding and close flag to realize the positioning of the frame header and frame tail. Since the format of the open flag and the close flag are both "01111110", in order to ensure the uniqueness of the open flag and the close flag, the open and close flags are removed during data encoding. Automatically insert a "0" every time 5 consecutive "1"s are encountered in other data outside the standard, and automatically delete every time 5 consecutive "1"s are encountered in other data except the open and close flags during data decoding A "0", but because the transmitted data is changing in real time, the number of "0" inserted in the data frame is also changing, and the length of the data frame using this encoding method is also uncertain, so that every The time required for frame data transmission is also different. Therefore, during data frame transmission, frame header identification must be performed first to achieve synchronization, and then delay reading data. The software processing process is more complicated, and the software design is more troublesome.

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