Low Voltage Power-Line Communication Simulation And Testing System Design

Low voltage power line communication has been paid more attention by people because of its advantage of low investment, high transmission rate, convenient usage, convenient for building home LAN and online forever. But it also brings several special difficulties to reliable communication because of its bad channel condition, electric network polluted seriously. Nowadays, lack of research on basic theories and full-scale experiment and testing environment affect fast development of power line communication largely.Based on power line transmission characteristic, this thesis set up a power line model using theory of uniform transmission line; design low voltage communication simulation and experiment system based on the model. This system is divided into some modules according as each affection factors of transmission characteristic; then, design hardware connection of each module, and add each module into purified electric network controlled by computer. As a result, by changing the given parameters such as waveform of noise signal, topology of electric network, load values, this experiment could simulate power line communication transmission environment under different area, different time, different loads and different disturbance condition, which provides a good experiment platform for research of low power communication technology.The experiment system includes: carrier wave send module, purified power, electric net topology, load net, noise signal source, coupler, and carrier reception module. This thesis design and debug electric net topology module, load net, coupler and purified source.This thesis adopts theoretical analysis method combined with experiment and testing. First, design hardware schematic of each module by theoretical analysis; then, adjust circuit parameters slightly by testing. So as to the system could emulate power line communication environment better.The testing data shows that this system could reflect transmission environment of low voltage power line communication. It could simulate resistance characteristic, attenuation characteristic and noise characteristic of different topology controlled by computer. In addition, this system is flexible to use and each module could be added on the users'requirements. It will provide a convenient and shortcut experiment environment.