Development Of Modular Distribution Automation Terminal Unit With Condition Monitoring

With the rapid development of Chinese economic, enterprises and residents’electricity consumption is growing higher and higher. Users pay more attention to the reliability of power supply and quality of power supply. While, more money is spent on power generation and power transmission than power distribution in China. This causes the low level of our distribution net construction and long outage time. Also, the reliability of power supply and quality of power supply can’t satisfy the users. The facts proved that the way of monitoring and clearing fault manually can’t adapt the complex distribution net now. It’s necessary to make the distribution net automatic.There are so many nodes of distribution net in China that the mount of feeder automation terminal is large. Because of the limited investment to distribution net, the cost of FTU must be under control. Also, for our territory is vast, the environment is very different to different location. So FTU must well adapt to harsh environment. The reliability of FTU is important, too. In addition, an important reason of too much outage time is that planned maintenance of distribution net. Using condition based maintenance instead of planned maintenance can shorten users’outage time effectively. There are some kinds of FTU at home and abroad, however, they ignore the characteristics of our distribution net and the practicability is limited.The elements used in this paper can satisfy all the functions of the system and the updating demands. The prices of these elements are fully considered as well. FTU is modulated so that it can be assembled into both cheap and practical ones for basic use or advanced ones with complete functions. It is easy to change the module which can avoid repeated investment. Wireless communication is used in the communication module, for it doesn’t need special channel and is easy to be installed. The specialty of the FTU used in this paper is that it includes on line insulation monitoring module. That’s the base of state maintenance of distribution system. As a result, planning maintenance is instead by state maintenance. The time of outage for planning maintenance can be reduced, which takes 80% of the total time. A multiclass anti interference system is designed as a guarantee for the reliability of FTU. The FTU presented in this paper is advanced and practical, adapting to the situation of China.