Economic Analysis And Optimal Selection Planning Of Distribution Feeder Considering Renewable Energy Sources

The distribution network is one of the essential components of the power system.The conductor size selection（CSS）in the distribution network planning（DNP）process will directly affect the economy and operation of the distribution network planning.In the low-carbon transformation of China’s power system,the penetration rate of renewable energy has increased significantly.The randomness and uncertainty of the output of renewable energy will lead to bidirectional power flow,and increased line loss and reliability in the operation of the distribution network.Therefore,it is highly non-trivial to analyze optimal CSS in the process of DNP,and further facilitate the construction cost and improve the efficiency of the distribution network.In this research,some essential challenges for distribution network planning and design under the new normal has been introduced,which based on the analysis of the impact of renewable energy on the operation and planning of the power system after large-scale access to the distribution network.Hence,considering the medium and long-term growth of regional load,the reliability and safety of system operation,and the randomness of distributed power output,a distribution network conductor economic analysis and optimal planning selection method based on a two-layer hybrid heuristic optimization algorithm is proposed.This algorithm tackles some existing problems,such as the typical distribution network planning methods are difficult to apply to the distribution network system containing large-scale renewable energy,the traditional planning techniques are relatively conservative,etc.Based on the proposed planning method,the key economic factors such as the life cycle cost of the distribution network construction,line loss,the purchase cost of renewable energy and traditional energy are considered and into mathematical modeling process.To solve the problems of discrete and multiple characteristic time scales input of the proposed mathematical model,this paper proposes a two-layer hybrid heuristic optimization algorithm for the above problems.The innovation model coupling strategy in the algorithm realizes the two-way self-learning between upper and lower model.It breaks through the difficulties of the existing algorithms,making it difficult to consider the economic benefits on various time scales and the conservative planning process.Finally,the mathematical modeling,simulation and quantitative analysis were conducted base on the IEEE-33 and IEEE-69 distribution network models.The simulation results show that the cost of life cycle decreased dramatically,which means that the proposed algorithm has better performance for optimal type and capacity selection of the conductor in distribution network.