A Hardware Design And Realization On Fiber Meter Reading System Based On EPON OLT

The combination of Ethernet and optical fiber communication evolutes a new technology--EPON (Ethemet Passive Optical Network), which is one of the most important technology to achieve high wideband transmission and integrated service access network. The topological structure of EPON system is point to multipoint point (P2MP) single-fiber bidirectional optical access network technology,and this link form can bear integrated service. The study found that because of a lot of defects, such as complex communication medium, low communication rate,the current remote automatic meter reading technology has been unable to meet the power requirement of the smart grid. This paper presents a fiber meter reading technology combined with EPON, to achieve low power optical fiber communication. This technology not only solves the above problems of the meter reading system, but also makes the power grid and the "Three net fusions" share EPON platform and accelerates the integration of " four networks of the future ".This paper from the solution of electric power communication system, aiming at the realization of optical fiber communication mode of power meter reading system, the main contents of this paper are as follows:(1) The theory analyses several familiar meter reading ways of the present remote meter reading system and analyses some shortcomings of it. Faced with the problems of the demand for smart-grid, the paper provides power meter reading scheme based on the mature EPON technique and provides EPON OLT design scheme of optical fiber meter reading system which meets the need of grid.(2) The paper designs the EPON OLT device applied to high density optical fiber meter reading system. It detailedly analyses the power source system of optical fiber meter reading OLT, the design scheme of clock system, selection of device and hardware circuit. It realizes some difficult techniques applied to meter reading, optical fiber meter reading in data between downlink and uplink and isolation techniques of network data. It meets the need of smart grid for low voltage power optical fiber communication. (3) the paper analyses the theoretical knowledge in the integrity of high speed circuit signal and the integrity of power source and the phenomenon that affects the integrity. And it analyses lamination design, impedance design, match termination, etc. techniques from the PCB design of high speed circuit and it makes simulation and analysis of high speed and power source. What’s more, it provides the scheme of system optimization.(4) The paper finished the debugging and configuration of EPON OLT system, imitates real phenomenon of meter reading to build a link platform of EPON optical fiber meter reading, and tests throughput and packet loss ratio of EPON optical fiber meter reading from OLT end to ONU end.The OLT combined the results of the system simulation and debugging, meet the performance requirements of power EPON. The following can be achieved:EPON uplink and downlink communication rate is symmetric1.25Gbps, the throughput of sending and receiving data from the OLT end and the ONU end is equal, packet loss ratio is δ=0.54%.