Design And Implementation Of Transmission Line Fault On-line Monitoring System For Zhengding Power Distribution Network

Zhengding County is regarded as the back garden of Shijiazhuang. No matter fromthe point of view of its geographical importance or from the fact that its economicdevelopment boosts the need for high quality power, we must co-ordinate urbantransmission and distribution network planning, promote the balanced development ofthe distribution network and other infrastructure planning, establish a strongdistribution network which is reasonable in structure, reliable and secure, flexible inoperation, environment-friendly, economic and efficient, and constantly improve thesupplying capacity of the distribution network so as to meet the demand of socialdevelopment and economic growth.To study and design and to install an online fault monitoring system is to focus onthe strategic goal of developing a unified and strong smart grid. On the one hand, thesystem can shorten the time for one to find the point of failure so that a lot ofmanpower and material resources can be saved. On the other hand, the system candetect the fault line timely, ensuring rapid recovery of power supply and reducingeconomic loss caused by power failure. Hence, online fault monitoring system hasenormous social and economic benefits and is a research topic of great importance.In this paper, I have summarized the existing international and domestic faultmonitoring system and analyzed the characteristics of various methods and techniques.Through the analysis of the status quo of the distribution network in ZhengdingCounty, we can know that if we are to strengthen the network construction and keep abalanced development of voltage levels, we should strengthen the transferring capacityof the next level of power grid, particularly the distribution network below10kv so asto enhance the overall reliability of the network. What’s more, the online faultmonitoring system is made up of fault indicator installed on the power line (includingdata transfer terminal), communications switch and monitoring center. The monitoringsystem software, running on the monitoring host, is the core of the whole system. Thesystem can be installed on overhead transmission and distribution wires and on theunderground cables of urban network. This system, used for monitoring the operatingsituation of power lines and fault conditions, is a set of smart fault management systemwhich can be distributed and monitored, managed collectively, with long distancetransmission capacity and instant notification ability. After the adoption of this systemin Zhengding County, the reliability of monitoring system increased from99.60%to99.76%, much closer to the index of99.9%set by relevant authorities and reaching thedesired effect of quick fault detecting and accurate positioning. After the installment,the annual power failure time reduced by671.60hours and the annual power loss by1071138.45KWH. In addition, direct economic loss was decreased by589126.15and indirect loss was also reduced by a large margin, thus the expected economic valuewas achieved.