Theory And Design Of Distributed Feeder Automation System

Since the distribution network is closely linked with the majority of electricity users, weather it is reliable or not determines directly the quality of the electricity. It is important to develop the technology of distribution automation. As an important part of it, feeder automation is applied to the feeders to monitor voltage and current as well as other electrical information in real-time and to automatically find and isolate faults and restore power. It is meaningful to improve the reliability and supply capacity of distribution network, and it could reduce electricity workers as well. Since the distribution network is complex, the current feeder automation models all have their own limitations. Based on existing distributed feeder automation models, the paper put forward a new, exhaustive solution. The main work of this paper is as follows:Based on the distributed intelligence feeder automation, the paper proposed a new fault-locating algorithm using the ortho-point switch matrix, and formulated different fault-locating criterions for the first switch and the remaining switches on a feeder. Based on the different current characteristics in the upstream and downstream of the fault, the algorithm could find the fault quickly by exchanging the currents in the neighboring switches, even if the fault happened after the last switch on a feeder, It is also capable of finding fault correctly in feeders connected more than one contact switches as well as feeders with passive branches.Based on the above algorithm, the paper proposed the fault handling process using for intelligent terminals, and provided three fault handling rules, which contains information exchange process and fault handling logic in terminals, as well as the process of mutual cooperation between neighboring terminals. The paper proved that the fault handling process could be adapted to multi-sectioned and multi-linked network and second fault, besides, it can still find fault correctly even if there exists communication failure in somewhere else.Based on PSCAD, the paper built a simulation model of intelligent terminals to simulate the fault handling progress of terminals when fault happens, at last, the result proved that the algorithm and the process is correct.The paper compared different ways of communication in distribution network, and proposed that EPON could be used as the primary means, then designed the networking solution, containing how OLT, POS and ONU connected to each other and their own settings. The paper also proposed the topology recognition strategy of ONUs.