Distribution Network Island Division And Fault Recovery Taking Into Account Distributed Power Generation

In recent years,with the development of science and technology in the smart grid,distributed generation(DG)is increasingly represented by wind power generation and photovoltaic power generation.Its permeability(penetration rate)is becoming higher and higher in distribution networks,and the traditional distribution network has made great changes in the mode of operation and control.A large number of distributed power sources are connected to the distribution network,which not only improves the voltage quality of the nodes in the distribution network and reduces the active loss of the entire network,but also allows the DG to supply power to the load nodes within a certain range independently after a failure in the distribution network.This can reduce the power outage after the fault and improve the power supply continuity and reliability of the distribution network.Of course,if the fault occurs,if we can transfer the non fault line to the safety line through the contact switch,the recovered power supply is more reliable.Therefore,this paper proposes a multi-stage recovery strategy based on the power supply capacity of distributed generation,the operation of the isolated island after the distribution network fault with distributed generation,and the location of the fault point after the failure of the distribution network.The main work includes the following aspects:(1)Based on risk standby power get DG foreign output power.Because the output power of the distributed generation is intermittently affected by the environment,the output power of the DG needs to be analyzed under island partition.At the rated power,the size of the power that can be output is highly reliable.Therefore,an effective operation is performed in the fault time period,so that the output power is based on the confidence level,which makes the output power more practical and reliable.(2)The power failure,and use of leapfrog algorithm for the optimization adjustment way to form the optimal island operation of the DG.This paper analyzes the importance and necessity of distributed generation to the continuity of distribLution network when island partition is carried out in the distribution network after faults occur.Distributed generation can form islands of power and operate stably.This is an important precondition for island partition after a fault in the distribution network.The distribution network is simplified and a tree backpack model is formed,which is mainly based on the island partition requirements,to recover as much of the higher priority load as possible,maximizing the ultimate benefit.Under the electrical constraintsneeds and topological constraints,the optimal primary island is calculated by the frog leaping algorithm.Since the bus load is controllable,uncontrollable and priority,the primary island to be adjusted to maximize the benefit value of the recovery load and form the final island.(3)Using the topology dynamically update and distribution network optimization to get failure recovery strategy.After a fault occurs in a distribution network,an island formed by DG can restore the power supply of the load.However,the operation of island is more fragile than the general grid connection structure.Therefore,After fault occurs,the first analysis of the fault point location,if in the loop,through dynamic topology update of transferring the fault area to the secure line.Due to the presence of DG,so quick get network has better network features,Later in the new network node voltage and network losses using particle swarm optimization(pso)algorithm for further optimization.The scheme can be combined with island operation,constitute a relatively comprehensive solution after a good distribution network fault.Such a scheme,not only can quickly restore power and interlocking fault occurred in distribution network is very effective.