Study On Decision-Making Method Of Operation Mode For Coordination Of Economy And Relibility Of Distribution Network

With the development of the scale of distribution network, the network structure and connection mode of distribution network become more complex, thus the operation mode arrangements for distribution network become more difficult. Currently the operation mode for distribution nework is rely mainly on the scheduling staffs’ experience, lacking scientific theoretical guidance and technical support. It is easy to cause the distribution operation mode unreasonable, rsulting in incoordination of reliability and economy. Therefore, study the reasonable decision-making of operation mode for distribution network is of great theoretical and practical significance to realize the coordination of reliability and economy from the features and the operation requirements of distribution network. Based on these, this paper does an analysis and research on the subject from the the way for coordination of reliability and economy. The main research contents of this paper are as follows:① The problem aiming at the loss and reliability in different operation mode of distribution network is analyzed. Based on the loss analysis in different operation mode under the typical connection mode of distribution network shows that, the distribution network operation mode has an important influence on loss, and the loss can be reduced through the reasonable arrangement of distribution network operation mode. Based on the reliability analysis in different operation mode under the typical connection mode of distribution network shows that, the distribution network operation mode has an important influence on the reliability, and the reliability can be improved by reasonable arrangement of distribution network operation mode. Through the loss and reliability analysis in different distribution network operation modes, a theoretical foundation for the decision-making of operation mode for coordination of economy and reliability of distribution network is laid.② In order to realize the coordination of operation economy and reliability, the lower-loss operation mode decision-making model of distribution network under the constraint of reliability and its solving method are proposed. The power distribution reliability constraint is taken as the premise and the electrical energy losses are taken as the objective during the decision-making period, with the model built considering other constraints including network structure and maintenace plan. According to the characteristics of the model, an EPA combined with improved random mutation strategy is put forward. The lower-loss operation mode considering multiple constraints is determined through searching the states of switches based on load prediction in decision-making period. The proposed model can effectively coordinate the economy and reliability of distribution network operation. It also has a guiding role in coordination of the arrangement of operation mode and implementation of maintenance plan. Meanwhile, the proposed algorithm can make the operation mode automaticly match the network structure constraint, thus a lot of invalid search are avoided and the search efficiency is improved.③ In order to further coordinate operation economy and power supply reliability of distribution network and to get higher quality electric power, the multi-objective decision-making model of operation mode for distribution network based on fuzzy evaluation is established. Taking the minimum electric energy loss, lowest power supply reliability and minimum node voltage offset as objectives and considering the constraint conditions including network structure and maintenance plan, a operation mode meeting multi-objective integrated optimal determined based on load prediction in decision-making period. The proposed model can effectively coordinate the operation economy and reliability of distribution network and ensure the quality of power supply. Meanwhile, the model can assign each target different weight according to its own characteristics, different operation condition and demands to distribution network operation. It can meet the special needs of the related indices for distribution operation and has broad applicability.