Fault Location And Power Supply Restoration For DG Distribution Network Based On Improved Harmony Algorithm

With the introduction of a large number of distributed power supply power distribution system,the traditional distribution network structure and operation mode changes to the distribution network fault location and power supply recovery has brought new problems.In this thesis,an improved harmony algorithm is proposed to solve the fault location and power supply restoration scheme with distributed power distribution network,which is of great practical significance to improve the safety,economy and reliability of distribution network operation.The thesis expounds the basic principle of harmony algorithm,and the method of improving the optimization ability of algorithm is discussed to improve the optimization ability of the algorithm by solving the problem that the algorithm is easy to fall into the local optimal and slow global convergence.On this basis,a multiobjective improved harmony algorithm which can solve the multiobjective optimization problem is proposed,which provides an effective calculation method for fault location and power supply restoration.According to the fault location problem of distributed power distribution network,a switch function which is suitable for multiple distributed power supply switching is established by defining the upper power supply,and the positive direction of the distribution network switch is defined.Method to simplify the network,the improved harmony algorithm used in distributed distribution network with fault location.The effectiveness of the algorithm is verified by an example,and the improved harmony algorithm has better searching ability and less time in the optimization process than the harmony algorithm.After a fault in the distribution network,this thesis further discusses the optimization scheme to restore power to the non-faulty power outage area.Firstly,considering the islanding effect of distributed power supply,the partitioning of DG is carried out to ensure the reliability of power supply of important load.Then,the power supply network loss,the node voltage offset index and the minimum number of switching operations are proposed.Application of multi-objective improved harmony algorithm to optimize the power supply recovery scheme for non-fault power outages outside the island.Finally,according to the importance of the decision-maker to optimize the target,an evaluation mechanism of the scheme for non-fault power outages is proposed to provide guidance for the decision-makers.The validity of the islanding method,the power supply restoration algorithm and the evaluation mechanism are verified by the IEEE 33 node test system simulation.