Optimal Multi-objective Model And Methodology For Net Power Distribution

Planning of distribution network is a complex system optimization problem which is characterized by uncertainty, nonlinearity, multiple objectives and dynamics, etc. Under the direction of distribution network planning theories, multiple objective planning, genetic algorithm, MATLAB optimization tool, optimization method of multiple objective economy concerning distribution network, quantitative computation on reliability planning disadvantages costs, comprehensive economy and reliability planning evaluation system were studied in the thesis, which are as follows:First, the recent development and existing problems of static model, dynamic model, objective model and multistage multiple objective model were analyzed and summarized based on analysis and researches on existing power transmission and distribution network planning optimization model according to the classification basis of planning time, objective function and economic reliability. Further, the simplification and improvement methods for the optimization of models were summed up from the prospective of linearization of nonlinear model, normalization of multiple objectives, static state of dynamic model and single level of hierarchical planning based on the understanding of the simplification and improvements on conventional power transmission and distribution network models, in which the research direction concerning power transmission and distribution network optimization model were described.Second, based on the researches on the economic optimization model of power transmission and distribution network carried out by predecessors and the comprehensive consideration on problems existing in economic power transmission and distribution network planning which are difficult to be resolved at present, the mathematical model of multiple objective economic optimization of regional power transmission and distribution network were argued by taking the related restrictions (e.g. economic current density section, active loss, power balance, N-1 safety criterion, directed topology, power limitation and voltage limits, etc.) into consideration, using the theories and genetic algorithm concerning radial connection and distribution network and multiple objective planning and management for reference and taking the construction investment costs and the minimum annual network losses costs of power supplier as objective function. The processing method of real code parallel optimization, method introducing annealing penalty factor to the design of dynamic penalty function to handle the restrictions, self-recognition decoding method based on genetic algorithm of power grid path and flow and self-adapting adjustment methods of genetic operators were studied mainly in terms of algorithm, so as to ensure that the genetic algorithm can restrain radial power distribution network topology, improve the ability to deploy self-adapting power distribution network and power supply path, ensure the search direction of feasible solution and ensure that the genetic optimization can be carried out smoothly.Third, two main influencing factors (effective capacity of overload branch in load shed node system and unit load shed cost of the node) were analyzed for the quantitative analysis and computing of minimum power shortage cost based on the qualitative analysis of interruption loss data statistics in direct power shortage cost, questionnaire qualitative evaluation method and the computational method of user power shortage loss in indirect power shortage costs. The reliability index can be converted into economic index in a more reasonable way with direct current flow model, dual power hand-in-hand connection way, the best load shed node position, evaluation conditions for load shed, quantitative analysis and the power shortage costs used for computation of minimum load shed, so as to meet the requirements on reliability and economy evaluation of planning program.Finally, the comprehensive economic and reliable power distribution network planning evaluation indexes system were established based on the selection principles for power distribution network's multiple objective planning evaluation indexes and the reliability economic evaluation method for common power distribution network system; based on the researches and analysis on comprehensive economy and reliability costs balance relation, economy evaluation principles for power distribution network, safety and stability rules, reliability requirements and relevant evaluation indexes, the operating methods and implementation procedures for power distribution network planning evaluation system were argued according to two stages in evaluation indexes (primary settings and analysis of planning evaluation).