Power Line Carrier Automatic Meter Reading System

Communication of power line carrier is a particular communicating manner which making use of high voltage power line, middling voltage power line or low voltage power line which be used as medium of transmitting message to transfer voice and data.Alongwith the technology of power line carrier developing and socity's requriment, the communication of middling voltage power line and low voltage power line has a good empoldering, and become an important part of domain in electric power communication.Combine with the actuality of domestic electric power market and the requirment of concentrate calling meters system, the text overpass coparing many different forms concentrate calling meters system, analyzed the feasibility of automatic calling up meters by dint of power line carrier.But the low voltage power line is not the perfect medium, the most reason is that it has bad environment, very low input inpedance,and it attenuates and jams the signalsgreatly.The text analyzed the channel characteristic of low voltage power line, and make a lucubration about modulating mode of concentrate calling meter system in using low voltage power line.Bring forward a viewpoint that is adopting OFDM technology.The principium of OFDM technology is that dividing the presentchannel into Orthogonal sub channel, by use of sub carrier wave make modulation in each sub channel, and transfer each sub carrier wave. Despite the channel is not smoothly,but each sub channel is smoothly and the signal be transferred by narrowband in sub channel,which can avoid disturber between sigal wave.The traditional OFDM technology adopting complex exponential sub carrier wave base on Fourier transform, which is makeup by many orthogonal cosine function group. If sub carrier wave can be replaced by the new orthogonal gooup ,the capability of OFDM can be improved on. The text according ISI and ICI of multicarrier system's power big or not, study it's capability, bring forward the multicarrier wave communacation using low voltage power line which bases on orthogonal wavelets has adventage on improving the capability of signal transmission.According the standard of electric power trade,the system make good winning on simulating test, can provide many function such as call on meter,managing electric fee, power supply and stop supply, real time control etc.