Research On Optimal Allocation Of Distributed Generation Considering Distribution Network Reliability

In recent years,distributed generation(DG)technology has been increasingly introduced into power distribution systems due to its significant environmental performance and economical efficiency,transforming the traditional single source radial distribution network into a new multi-source network with power supply and user interconnection.At the same time,with the rapid development of the economy and the improvement of living standards,people have put forward higher requirements on the ability of the distribution network to provide high-quality power for important equipment.The optimal configuration of existing distributed power sources is generally considered to be a typical optimization problem.Most of the research on location optimization aims at improving the system economy or reducing the network loss.Researchs that take reliability level of distribution network into the optimal configuration of distributed generation are not enough to solve the optimal configuration problem in high-reliability power required scenarios.In order to solve the problems of traditional distributed power optimization method,a reliability based distributed power optimization model is proposed.The main research contents are as follows:This paper established a reliability assessment method for distribution networks with distributed generations.Simplify the distribution network by dividing feeder units,and perform heuristic island separation method based on distribution network operation state and distributed power output.Combine the island separation results with minimal path method of reliability evaluation to obtain the reliability index of each load point and system.Then,an optimal configuration model of distributed generation considering reliability index is established.Based on the established reliability assessment method,the objective function weights of the distribution network reliability index,total active network loss,and equipment operation investment cost are determined through the judgment matrix method to form a normalized multi-objective function.Combined with the characteristics of the distributed generation planning problem,the genetic algorithm is improved.The elite selection strategy was introduced into the genetic operation process,and the chromosome coding method and structure were improved.It can meet the requirements for solving complex optimization problems with multi-variable and multi-constraint conditions such as distributed power optimization configuration.It can also complete iterative calculations in a low-memory,high-speed,and no-decoding manner,with global convergence.Finally,an example is given to verify the method of this paper.The distributed generation configuration model of distribution network considering reliability and the improved genetic algorithm are used to optimize the location and capacity of distributed generation connected to the IEEE-33 node system.The results show that the optimized configuration of distributed generation considering reliability can greatly reduce the system power shortage index and provide users with higher power consumption guarantee.Further calculation of the benefits of increased reliability shows that although the initial investment in the installation of distributed generation is relatively large,the poposed method is still economical in the long run.