Optimal Placement Of Phasor Measurement Units And Communication Devices For Distributed State Estimation In Distribution Networks

With the expansion in scale and complexity of distribution networks,distributed state estimation(DSE),a real-time database for other on-line applications,is becoming popular for large-scale active distribution networks(ADN).Measurements from PMU with the same time stamp can assist DSE to obtain faster and more accurate estimation;however,the configuration of PMUs and communication devices should be updated to support data collection and transmission.This thesis proposes an optimal PMUs and communication devices placement method for DSE in distribution networks.Taking wired communication as the main communication mode and wireless communication as the backup,data from PMUs can be suceessfully transmitted to PDCs,which provides data support for DSE.The main contributions of this thesis can be summarized as follows:1)A distribution network partitioning method only based on partitioning principles of DSE is proposed.By transforming network partitioning to the problem of allocating a central node of each subarea,the partitioning scheme with balanced scale among subareas is obtained through genetic algorithm(GA).Case studies on IEEE 33-node,PG&E 69-node and IEEE 123-node systems verify the feasibility of this method.2)With the lowest configuration scheme cost as the objective function,a binary integer linear programming model of optimal PMUs and communication links placement for DSE is established considering observable constraints of subareas,data uploading constraint of PMUs,decision variable constraints on overlapping nodes,information interaction constraints between PDCs and placement constraints of wired communication links.By introducing the traffic model of PMU and PDC,both the bandwidth cost and length cost of communication link are considered.The economy of the configuration scheme is guaranteed on the premise that the network is fully observable.IEEE 33-node,PG&E 69-node and IEEE 123-node systems are utilized to verify the effectiveness of the method.3)An optimal distributed wireless sensors placement method for data transmission from PMUs to PDCs is proposed.By dividing distribution networks into a set of meshes,the complexity of the wireless sensor nodes deployment is reduced.Wireless network adjacent matrix is employed to determine whether wireless communication is observable.Taking the minimum number of wireless sensor nodes configured in the network as the objective function and considering the sensor configuration constraints of PMU and PDC nodes and the observability constraints of wireless network,a distributed wireless communication configuration model of PMUs oriented to distributed state estimation is established and solved by GA.