Method and device for realizing clock synchronization based on sdh network

Abstract

The invention provides a method and apparatus for realizing clock synchronization based on an SDH network. The method comprises the following steps: when a GPS card arranged on a main clock monitors that a GPS antenna has no input signal, obtaining a clock signal of clock frequency input by the SDH network connected with the GPS card; and outputting PPS according to the clock signal of clock frequency input by the SDH network. As the SDH network is a synchronous network, the normal transmission of network data is guaranteed. when the GPS cannot search a GPS satellite, clock synchronization is realized by high-precision 2.048MHz frequency input on the SDH network, so that the main clock can still keep the clock synchronization of a submicrosecond level for a relatively long time, and even if the GPS cannot search the GPS satellite, punctuality of several days or longer can be maintained without exceeding the precision of 1 microsecond. By adoption of the method, the requirements of clock synchronization in the electric power industry can be not only satisfied, and an enough time can also be provided for a user to locate, analyze and recover the abnormal conditions of the GPS satellite.

Description

technical field [0001] The invention relates to the field of industrial Ethernet technology, in particular to a method and device for realizing clock synchronization based on an SDH network. Background technique [0002] In power systems, places such as power plants or substations require very precise time-synchronized control. Millisecond or microsecond-level time synchronization deviation will cause system interruption and even paralysis of the power grid, which will bring huge losses to customers and power companies. [0003] At present, a master clock with GPS will be used inside the power plant or substation as the master clock of the entire internal system of the plant, and all equipment (slave clocks) will synchronize with it. However, once the GPS cannot find GPS satellites, and enter After the punctual phase, the precision of hundreds of nanoseconds may be maintained in a short period of time (for example, one or two hours), but if the time is slightly longer, it w...

AI Technical Summary

Problems solved by technology

Millisecond or microsecond-level time synchronization deviation will cause system interruption and even paralysis of the power grid, causing huge losses to customers and power companies

[0003] At present, a master clock with GPS will be used inside the power plant or substation as the master clock of the entire internal system of the plant, and all equipment (slave clocks) will synchronize with it. However, once the GPS cannot find GPS satellites, and enter After the punctual phase, the precision of hundreds of nanoseconds may be maintained in a short period of time (for example, one or two hours), but if the time is slightly longer, it will exceed the range of 1 microsecond, which cannot meet the 1 microsecond required by the power industry Accuracy requirements

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