Optimum Control Of Electric Power Distribution Network

A new model of distribution system is presented, whereby, the feeder switches are regarded as the vertcxes of a graph and the feeder lines are regarded as the arcs. The method to model distribution networks by adjacent table is put forward. Therefore, storage size is reduced and calculation is speeded up. Method of distribution network topology making based on adjacent table is also discussed.A simplified analysis method of distribution networks is presented. The voltages and the power on/through both end of the feeder are used to describe the load and its distribution within the feeder line. Only field test datas from feeder circuit breakers in substations, switches along the feeder lines and on the loop points are needed to obtain a sactisified analysis result. Basic principle of the simplification is detailed. Feed lines with branches is also discussed. The proposed approch is verified by branch current based power flow calculation.A novel distribution network optimal control approach for load balancing is presented based on the simplified model of distribution system, in which tie switches are regarded as critical elements. The two feeder lines connected with a tie switch are regarded as a feeder couple. Load balancing ratios of feeder couples and total distribution network are defined and be used as indice of network reconfiguration, respectively. Thus a network reconfiguration procedure is made up of several loadbalancing processes within a feeder couple. Distribution network optimal control approach for loss reduction is discussed based on the proposed method.The concept of Minimum Distribution Part(MDP) is put forward together with the adjacent table based method to divide a distribution network into several MDPs. Based on above theory; a novel way to identify fault sections of a distribution network is presented. Algorithm to isolate the fault section with minimum switch operations and identifying of over-tripped switches are discussed. Fault section identification and isolation of distribution network with reclosers and sectionalizers are also talked about. Based on load balancing, the way of optimal restoration is disussed.