| Under the pressure of severe energy situation and the human environment, humans began to seek solutions for energy and environmental issues. Thanks to the emergence of new renewable energy with the advantages of environmental protection, economy, reliability, flexibility, and its development caught the attention all over he world. When a large number of Distributed Generation (DG) access to the distribution network, it has changed the traditional distribution network power unidirectional flow characteristics, so the distribution system is facing many new challenges:on the one hand, various types of DG has its own operating characteristics, such as:intermittent output, uncertainty, non-scheduling, which presents new challenges to the computing of power flow in distribution network; on the other hand, building the optimization model of the distribution system with DG should combine the planning of DG and reactive power compensation devices, and its computing algorithm is also facing new challenges.In this paper, the above two problems are explored and researched. Firstly, it describes several typical DG works, node types, and analyzes the impact of DG to the grid; Secondly, considering the random fluctuations of the output of DG, this paper presents the trend of using probabilistic power flow calculation method; For the planning and configuration issues in distribution network with DG, the integration of the sensitivity analysis of voltage and power loss is used to determine the installation position of DG. When building the optimization model considers the economic performance and technical safety performance indicators at the same time, and the improved genetic algorithm is used to solve this problem. The calculation results show that the integrated planning and configuration of DG and C which based on probabilistic power flow calculation and comprehensive sensitivity analysis is more efficient and the improved quality of voltage is significantly higher than that of DG and C planning alone.Finally, when doing the dynamic reactive adjustment in distribution network with DG, the impact of power loss, voltage and large-scale power capacitor switching limits of centralized control are considered. This paper makes use of electrical distance and dynamic a decomposition method to do dynamic partitioning of distribution network, regards the resulting power loss as the objective function, and takes the actual amount switches of capacitor as control variable. The results show that after the comprehensive planning and configuration of distribution network, doing dynamic reactive power adjustment can effectively reduce the actual switching frequency of capacitor, thus prolonging the life of equipment, reducing its investment costs, further reducing energy loss and improve the voltage level in distribution network. |
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