Study On The Fixed Capacity Of Distributed Power Supply In Distribution Network With Reactive Power Optimization

In the thirteenth Five-Year Plan, appropriate restrictions are proposed for the development of thermal power, while the development of distributed generation is actively encouraged. The State Grid Corporation has also introduced policies to encourage the grid-integration of distributed generation. Combination of distributed generation with distribution network is universally believed as an important future development trend of electric power, and the interconnected location and capacity of distributed generation will have a great influence on the operation of distribution network. This dissertation studies the locating and sizing of distributed generation in distribution network with optimal capacitor allocation and reactive power optimization, which can improve power quality of the network and reduce the power losses. Not only can it improve economic efficiency but also bring enormous social and environmental benefits. The main research contributions are as follows:(1)This dissertation selects power loss, the sum of voltage offsets of all nodes, total cost of the construction and operation of distributed generation and compensatory cost of environmental pollution as optimization objectives. The locating and sizing model of distributed generation by normalizing weighted multiple objectives to a single objective is established, then the improved genetic algorithms in order to optimize the model calculations is used. Simulation experiments show that voltage support level and reduction ratio of loss in the distribution network are improved.(2)Based on the locating and sizing of distributed generation, this dissertation uses shunt capacitors as the reactive power optimization objective of distribution network. By combining power loss, voltage offsets under constraints and compensatory cost of power offsets as the integrated optimization objectives, we adopt the improved multi-objective genetic algorithms to optimize the allocation of parallel capacitors. We can conclude from the simulation examples that the optimal allocation of reactive power based on the locating and sizing of distributed generation can further improve voltage support level of nodes and reduce network losses.(3)According to the research and analysis conducted in a 6MW photo voltaic power generation project in northern Jiangsu during internship, this dissertation proposes a designing scheme for actual grid-integration with type of distributed generation determined. Furthermore, suggestions of improvement measures and ideas are offered for reference. Meanwhile, by investigating the construction of distributed generation under various conditions in inland areas of northern Jiangsu, the rationality and possibility of distributed power generation for distribution network is proved in this dissertation.(4)Applying the proposed locating and sizing of distributed generation and scheme of reactive power optimization to a 21-node distribution network model in Northern Jiangsu, this dissertation uses improved genetic algorithm and provides four different network configurations, each laying particular emphasis on all the factors. Then we obtain the optimal program of distributed generation and reactive power compensation equipment from the top configuration of the sorted (using AHP) four.