Based On The 2Mbit/s Optical Interface Of Relay Protection Signal Transmission Reliability Research

Relay protection plays the increasingly important role of safety and reliability in the power grid.In addition to the requirements of reliability,sensitivity and speed of relay protection device,therefore the transmission channel is needed to send the protection signal accurately and quickly in order to cut off the fault point in the shortest time,it expects much the reliability of transmission Channel.In the operation of the power system,the relay protection signal is mainly transmitted through the synchronous digital hierarchy(SDH)optical network,But the relay protection device and SDH equipment between the need for photoelectric conversion equipment(such as MUX2M)to achieve the interface matching,there are many problems such as complex interface connection,multi photoelectric conversion,poor channel stability and so on,which can cause the relay protection device reject action,and the photoelectric conversion device is not subject to the transmission system network management monitoring,but also for the communication sector debugging,troubleshooting caused great inconvenience.In order to solve the above problems,a new 2Mbit/s optic-interfaces technology standard is proposed for China Southern Power Grid(CSG),Suitable for the relay protection device and SDH equipment to form fiber direct connected,thereby reducing the intermediate photoelectric conversion device,which is of great practical value to improve the Stability of the relay protection-communication system,and the convenience of operation and maintenance.According to the 2Mbit/s optic-interfaces standard,the related communication enterprise developed the transmission device,and delivered to CSG to carry out the operation test.The communication department which in my work has assumed the stability test of the 2Mbit/s optic-interfaces of ZTE S3 85 transmission equipment.I designed this paper test plan,and select the optical channel of 220kV JinMa substation—220kV Taocheng substation in Guangxi Chongzuo District power gr:id,to carry out 2Mbit/s optic-interfaces test:including optical interface parameter test,network management monitoring function test,intercommunication test,stability test and relay protection device hanging action test.In order to verify whether the 2Mbit/s optic-interfaces can fit together for relay protection device and transmission equipment,whether the relay protection device correctly reflects the protective action.According to the quality of relay protection signal transmission in the current electric power dispatching communication technology standard,i had calculated,measured and analyzed the transmission error characteristics and transmission delay of 2Mbit/s optical communication system,the final result is in accordance with the standard of power dispatch.And the relay protection device can correctly reflect the protection action,with no error code and alarm.This paper proves that the reliability of 2Mbit/s optic-interfaces fully meets the requirements of relay protection signal transmission,and can replace the current relay protection device and SDH optical transmission equipment connection mode.