Research On Distribution Network Reconfiguration Containing Distributed Generation

Distributed Generation is an environment-friendly,small to medium-sized generation that introduced in distribution network to improve its reliability and economy.With the distributed generation access in distribution network,which affected to the power quality and relay protection of the grid,The power distribution of network will change when its power generating change at random with the time and temperature.DG power systems is quite characteristic for provide power:DG usually placed near the users,low losses power of lines;high energy efficiency;short constructing period;little investment and less pollution.good environment compatible.DG also can realize the multiple resources and areas complementation well,meanwhile operation flexible and high reliability guarantee.For the past few years,Distributed Generation have been recognized as an excellent environmental protection properties and highly complementary,and has become one of the hottest research topics of world energy system development.Distribution network reconfiguration is by changing the sectionalizing switches and loop switches to change the network topology.With the rapid development of Distributed Generation accessed will has great influence on the the power structure and operation.So,study the distribution network reconfiguration combining the Distributed Generation accessed has the realistic meaning with importance.Traditional network reconfiguration mainly takes static reconfiguration a lord,in actual power distribution network operation,each node load varying,and limited of service life of sectionalizing switches and loop switches,its has a limit of operation times,would not change the network structure frequently.Therefore,Synthesizes the load dynamic change and Distributed Generation outputs variation may ensure distribution network reliable and economic.So,considered the load dynamic change and Distributed Generation outputs variation would be practical meaning.In this paper,the distribution network reconfiguration containing DGs and multi-period reconfiguration considering load variable and distributed generation output random are studied.The contributions of this paper are summarized as follows.Firstly,Introducing the concept of distributed generations and several common distributed generation technologies are introduced.different DG types math model in load flow calculate is established,then,put the math model into the load flow calculation baed on gradation,The practical examples have proved the efficiencies of the processing model and load flow calculation.Finally,make a qualitative analysis of the influence of the distribution network loss after the different site and size of DG access to distribution network.Second,In this paper,a distribution network reconfiguration containing DG method is proposed.During the reconfiguration,An advanced quantum-particle algorithm was presented.The algorithm is improved from three aspects:differential evolution strategy are executed in order to maintain the population diversity;Using the integer-coded in QPSO to solve the optimization problem of integer and transfer infeasible solutions into integer solutions.Aiming at the problem of the processing of traditional particle method,mutation operator was introduced in this crossing particle to avoid plunging into local optimum.Utilizing the improved algorithm called HDQPSO to solve the problem of distribution network reconfiguration containing and make an analysis of the influence of the distribution network loss when different site and size of DG access to distribution network.Finally,the paper presents a mutil-period recongiguration method,According to the set reconfiguration times by comprehensive performance indicators which important terms including network loss and static voltage stability.combined the influences of of load varying and distributed generation output randomicity.Realizing the network multi-period reconfiguration with the aiming to minimizing network operation costs,then confirming the best reconfiguration moments,combinations of switches and operation costs,The results presented the validity and feasibility of the method in this paper.