Development Of New Feeder Terminal Unit On Overhead Line

Feeder Automation is one of the most important contents of Distribution Automation. It is of critical importance to decreasing wastage, saving energy and improving the quality and reliability of power supply.The research on feeder automation is important to the construction of distribution autumation in our country.The Feeder Terminal Unit is the basic control unit of Feeder Automation and plays a significant role in Distribution Automation as well as Feeder Automation.The research and development of the intelligent Feeder Terminal Units applied in switch on the pole.Based on the research of feeder switch characters, some typical modes of fault handling are analyzed and a compositive mode is proposed,by this method, distribution substation receives and handles fault informations when conmunication channel is normal,when distribution substation or conmunicaion channel is broken, the FTU can automatically be a single conductor,It trips or closes the switch under the setting.The reliability of power supply is improved by these methods.The ratio of overhead power lines is comparatively high in distribution grid.But the functions of control devices applied in Feeder Terminal Unit are simple. Besides this, those devices have low adaptability.For the reason above, the idea and design of a novel intelligent electric device are presented in this thesis,which contains traditional functions such as four-remote function,feeder protection,power quality analysis, grounding fault protection etc.Besides these,the article discussed the feasibility and pactice method of GPRS technology applied in Feeder Automation system.And some critical technology problems such as device sourse swiching,energy-storage capacitor using for operating sourse are mentioned.In order to improve the adaptability and expansibility of FTU device,Hardware disturbances-proof design,device power reliable design and other intelligent technologies are reseached.A reliable hardware platform is developed consist of Floating DSP, MCU, etc.with a lot of methods of anti-jamming adopted.Based on these, supervision subsystem and ground sampling subsystem can be built on them. The single-phase grounding fault detecting in neutral point indirectly grounded power system is a hard problem for power utilities.Traditional methods of grounding fault line slection are analysed,and a method of partitioning feeder grounding fault protection based on FTU is proposed.Faults can be detected by FTU and fault partition can be checked out by the method.A new idea is provided for solving the problem.