Application And Research Of Middle Voltage Cable Carrier Communication In Distribution Network

With the higher demand of reliability in distribution, people more and more recognize the importance of distribution network, especially in automation of ditstribution network. The realization is completed by many intellectual equaments installed in distribution network. They perform some functions such as collection of data and power, default distinction, default isolation and so on. A reliable and stable distribution network is ensured by the large intellectual equaments which work depending on each other. In order to accomplish those functions,it demands that those intellectual equaments can communicate each other, so an open and reliable communication network is a key. After comparing several communication ways , I drown the conclusion that PLC is an economical and competitive communication way in power system.Being familiar with PLT-22 carrier chip, I do many experiments in low voltage 220V and summarize the all kinds of factors which affect the attenuation of low voltage carrier channels. I have some sensible recognization on the change of channel attenuation and analyze the attenuation and reflection of power line which have different impedance characteristic. At the same time ,I acquaint myself with LonWorks more deeply.In order to adapt the attemuation change of channels, I introduce an automatic relay technology and do large experiments in power line. The result is that this scheme can track the change of power line channel and the reliability of communication is improved. The cable carrier communication is the keystone of this paper. I survey the attenuation of cable channel ,introduce a theoretic calculation way and provide a calculation model which can compare the theoretic value and surveying value.In the cable carrier communication, the coupling technology is one of key points.The paper analyzes and surveys the LC200 coupler and improve the coupling efficiency. At the same time, the article introduces a new coupler-MCC which is welcomed by people and does the similar analyse.