In order to control the large-scale urban traffic network through hierarchical or decentralized methods, it is necessary to exploit a network partition method, which should be both effective in extracting subnetworks ...In order to control the large-scale urban traffic network through hierarchical or decentralized methods, it is necessary to exploit a network partition method, which should be both effective in extracting subnetworks and fast to compute. In this paper, a new approach to calculate the correlation degree, which determines the desire for interconnection between two adjacent intersections, is first proposed. It is used as a weight of a link in an urban traffic network, which considers both the physical characteristics and the dynamic traffic information of the link. Then, a fast network division approach by optimizing the modularity, which is a criterion to distinguish the quality of the partition results, is applied to identify the subnetworks for large-scale urban traffic networks. Finally, an application to a specified urban traffic network is investigated using the proposed algorithm. The results show that it is an effective and efficient method for partitioning urban traffic networks automatically in real world.展开更多
In this paper,a model of a large-scale optimal power flow(OPF)under voltage grading and network partition and its algorithm is presented.Based on the principles of open loop operations,the node injecting current metho...In this paper,a model of a large-scale optimal power flow(OPF)under voltage grading and network partition and its algorithm is presented.Based on the principles of open loop operations,the node injecting current method is used to divide the large-scale power grid into voltage grading and district dividing structures.The power network is further divided into a high-voltage main network and several subnets according to voltage levels of 220 kV.The subnets are connected by means of boundary nodes,and the partition model is solved using the improved approximate Newton direction method,which achieves complete dynamic decoupling simply by exchanging boundary variables between the main network and the subnets.A largescale power grid thus is decomposed into many subnets,making the solution of the problem simpler and faster while helping to protect the information of individual subnets.The system is tested for correctness and effectiveness of the proposed model,and the results obtained are matched in real-time.Finally,the algorithm is seen to have good convergence while improving calculation speed.展开更多
A rational partition is the key prerequisite for the application of distributed algorithms in distribution networks.This paper proposes community-detection-based approaches to a distribution network partition,includin...A rational partition is the key prerequisite for the application of distributed algorithms in distribution networks.This paper proposes community-detection-based approaches to a distribution network partition,including a non-overlapping partition and a border-node partitioning method.First,a novel electrical distance is defined to quantify the coupling relationships between buses and it is further used as the edge weight in a transformed equivalent graph.Then,a vertex/link partition community detection approach is applied to over-partition the network into high intra-cohesive and low inter-coupled subregions.Following this,a greedy algorithm and a tabu search method are combined to merge these subregions into target numbers according to the scale similarity principle.The proposed approaches take the influence of three-phase imbalance into consideration and they are decoupled from the power flow.Finally,the approaches are tested on an IEEE 123-bus distribution system and the results verify the effectiveness and the credibility of our proposed methods.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 60934007, 61203169, 61104160)the China Postdoctoral Science Foundation (No. 2011M500776)+1 种基金the Shanghai Education Council Innovation Research Project (No. 12ZZ024)the International Cooperation Project of National Science Committee (No. 71361130012)
文摘In order to control the large-scale urban traffic network through hierarchical or decentralized methods, it is necessary to exploit a network partition method, which should be both effective in extracting subnetworks and fast to compute. In this paper, a new approach to calculate the correlation degree, which determines the desire for interconnection between two adjacent intersections, is first proposed. It is used as a weight of a link in an urban traffic network, which considers both the physical characteristics and the dynamic traffic information of the link. Then, a fast network division approach by optimizing the modularity, which is a criterion to distinguish the quality of the partition results, is applied to identify the subnetworks for large-scale urban traffic networks. Finally, an application to a specified urban traffic network is investigated using the proposed algorithm. The results show that it is an effective and efficient method for partitioning urban traffic networks automatically in real world.
基金supported by National Basic Research Program of China(973 Program)under Grant 2013CB228205National Natural Science Foundation of China under Grant 51541707.
文摘In this paper,a model of a large-scale optimal power flow(OPF)under voltage grading and network partition and its algorithm is presented.Based on the principles of open loop operations,the node injecting current method is used to divide the large-scale power grid into voltage grading and district dividing structures.The power network is further divided into a high-voltage main network and several subnets according to voltage levels of 220 kV.The subnets are connected by means of boundary nodes,and the partition model is solved using the improved approximate Newton direction method,which achieves complete dynamic decoupling simply by exchanging boundary variables between the main network and the subnets.A largescale power grid thus is decomposed into many subnets,making the solution of the problem simpler and faster while helping to protect the information of individual subnets.The system is tested for correctness and effectiveness of the proposed model,and the results obtained are matched in real-time.Finally,the algorithm is seen to have good convergence while improving calculation speed.
文摘A rational partition is the key prerequisite for the application of distributed algorithms in distribution networks.This paper proposes community-detection-based approaches to a distribution network partition,including a non-overlapping partition and a border-node partitioning method.First,a novel electrical distance is defined to quantify the coupling relationships between buses and it is further used as the edge weight in a transformed equivalent graph.Then,a vertex/link partition community detection approach is applied to over-partition the network into high intra-cohesive and low inter-coupled subregions.Following this,a greedy algorithm and a tabu search method are combined to merge these subregions into target numbers according to the scale similarity principle.The proposed approaches take the influence of three-phase imbalance into consideration and they are decoupled from the power flow.Finally,the approaches are tested on an IEEE 123-bus distribution system and the results verify the effectiveness and the credibility of our proposed methods.
