Research On Oilfield Distribution Network Reconstruction Based On Graph Theory And Network Optimization Algorithm

Oil is the basic raw material that protects our industrial production, and the power distribution network of oil field is a necessary condition which ensures the oil production. Problems in the oil distribution network include irrational layout, dispersed load configuration etc. These problems easily lead to larger losses of power distribution network and lower quality of the supply voltage, which are not conducive to providing a reliable electricity supply for gas resources exploitation. The power distribution network reconfiguration can reduce total system losses, improve power quality and achieve optimal operation of the power distribution network. Through changing the connected or disconnected status of the switches and transferring load between the substations or feeders, the power distribution network reconfiguration changes the network power flow. Finally, the network topology which meets the requirements is obtained.There are several main points of studies on the problems of power distribution network optimized reconstruction in this article. Firstly, based on the summary of various power flow algorithms, a power flow algorithm of three-phase power distribution network based on the node-branch incidence matrix has been derived, after simplifying the power distribution network and transferring it into the structure of graph theory. In addition, based on the summary of the commonly used power distribution network reconfiguration algorithms domestic and overseas, a power distribution network reconfiguration algorithm that combines graph theory and network optimization has been proposed. Meanwhile, the working principle and process of Kruskal algorithm, Dijkstra algorithm and Floyd algorithm has been described. Besides, the mathematical model of the power distribution network reconfiguration has been built, with the minimum network losses being taken as the objective functions and the constraint conditions being met. In addition, a graph theory knowledge combined graph theory model of power distribution network has been built according to the closed-loop design and open-loop operation feature of power distribution network. Furthermore, the weight matrix in graph theory model has been set according to the power flow results, and the distribution network reconfigurations of33-bus system and PG&E69power distribution system have been conducted utilizing Kruskal algorithm, Dijkstra algorithm and Floyd algorithm respectively. Through verifying the validity of the algorithm, the optimization and reconfiguration of the three algorithms in practical power distribution network of oil field have been achieved. Ultimately, the optimal network topologies which meet the requirements have been obtained. The simulation calculations of power distribution network reconfiguration that based on graph theory and network optimization algorithms have been proceeded in MATLAB2010(a). The results show that in the standard power distribution network, the reconfiguration results are similar with the reconstruction results of intelligent optimization algorithms, thus verifying the effectiveness of the algorithm. By reconfiguring the actual power distribution network of oil field, the network loss declines and the node voltage increases. The analysis of examples shows that the power distribution network reconfiguration algorithm, which combines graph theory and network optimization, has an important significance for reducing the production cost and improving the overall efficiency of oilfield, and can provide a reference for the realization of the network automation and grid construction of the entire oil production plant.