Research On Fault Recovery Of Distribution Network Containing Microgrid

At present,the rapid development of industry has brought about energy crisis and environmental pollution problems.The clean utilization of renewable energy power generation technology has gradually attracted widespread attention in academic circles.Although the distributed generation mode is flexible and changeable,it also has many shortcomings,such as unstable output.Micro-grid,as an independent small network,can solve the intermittent and unstable of distributed generation.Due to its own complexity and natural conditions,the distribution network will inevitably cause some large-scale blackouts.After the micro-grid is connected to the distribution network,the structure of the large power grid is more complicated,but it also increases the flexibility and diversity of the distribution network,which can meet the different requirements of users.It has advantages and disadvantages for the fault recovery of the distribution network.In this thesis,the topological structure and power flow calculation model of distribution network are firstly established,and the forward-backward substitution method in power flow calculation is introduced in detail,and taking IEEE33 node model as an example,using Matlab to simulate and verify the correctness and feasibility,which is helpful for us to better formulate the fault recovery strategy.Secondly,analyze the influence of the micro-grid access to the distribution network,combine the depth-first search algorithm and the layered idea,consider the importance of the load,and formulate a dynamic island division scheme.If necessary,remove the three-level load inside the micro-grid.Ensure that the micro-grid capability can be fully utilized in the fault recovery of the distribution network,recover more power loss load,and reduce power outage losses.Then,the mathematical model of fault recovery in distribution network with micro-grid is established.An improved binary combined mutation particle swarm optimization algorithm based on particle swarm optimization and genetic algorithm is proposed to develop a fault recovery strategy for distribution network with micro-grid.Specific recovery strategy process;Taking the IEEE-33 as an example,the micro-grid is connected at some nodes to study how to fully utilize the micro-grid to restore power to the large-area non-faulty power loss area of the distribution network.Compared with the fault recovery effect of the distribution network without micro-grid,the simulation results show that the total power loss of the fault recovery of the distribution network with micro-grid is less,the network loss is less,the system voltage is obviously improved,and the fitness is improved.The value is small and the recovery effect is better.By comparing the convergence curves of the combined mutation particle swarm optimization algorithm with the binary particle swarm optimization algorithm and the improved ant colony algorithm,the rationality and superiority of the proposed scheme are verified.