Reactive Power Optimization Of Distribution Network Containing DG Based On Improved Genetic Algorithm

The contradiction between power requirements and environmental pollution has become increasingly prominent with the economy continues developing, in order to improve the shortage of the conventional power generation mode and the power supply mode, and to improve the energy structure, in the meantime to reduce environmental pollution, the Distributed Generation technology based on new source of energy is gradually on the rise.Various types of DG has been incorporated into the grid to solve the power shortage problem of large-scale centralized power supply mode by providing energy for remote areas and islands in situ, but it’s also brings a series of influences. The trend of the entire distribution network will be affected while the structure of the grid which is with DG has been changed, and then the safety, the reliability and the economical efficiency of the grid will be attacked,for the voltage quality of the grid will be affected by the distribution of reactive power, So the reactive power flow must be strictly controlled when the DG connect to the grid, and its balance must be maintain by providing reasonable compensation of reactive power, thereby improving system power quality, reduce energy loss, and to ensure the security of the distribution network operation, also the reliability and economical efficiency.Firstly, the background and significance of this paper have been introduced. The concept and classification of distributed generation technology, and the impact of distributed generation technologies to the power systems have been elaborated in detail, the significance of reactive power optimization and typical optimization algorithm has been studied; the research status of distribution network reactive power optimization which is with DG has also been researched, finally the main work contents of this paper has been introduced.The second chapter introduces the concept and significance of distribution power flow calculation in detail and the traditional flow calculation methods has been studied. The interface model of DG connecting to the grid has been proposed, and the flow calculation method of distribution network with DG has been put forward based on the analysis of the advantages and disadvantages of different flow calculation methods.The third chapter studies the traditional genetic algorithm’s basic algorithm thought and computing design steps firstly, and then an integrated improved genetic algorithms has been put forward based on the shortcomings of traditional genetic algorithm, and its algorithm ideological has been introduced in detail. Finally the comparison between improved genetic algorithm and traditional genetic algorithm has been done based on a function instantiation, and the result shows that the improved genetic algorithm parameters has better stability, and less precocious.Lastly, based on 36 node grid simulation example, using wind power and fuel cells, studied the structure and characteristics of the grid which is with DG, and the basic idea of reactive power optimization has also been studied in detail, the interface mathematical modes of different kind of DG connecting to the grid have been put forward, And its corresponding objective function and constraints have also been given. And then the reactive power optimization of traditional distribution network and distribution network with DG has been compared. The results shows that the security of the distribution network has been improved and the economical efficiency have been reduced by using DG to distribution network’s reactive power optimization.