Genetic algorithm based power distribution system network structure optimization method

Abstract

The invention relates to a genetic algorithm based power distribution system network structure optimization method. A mathematic model taking minimal unit power supply capacity expense as a target function is established, the contact branch length, contact capacity, regional load demands and total number of contact channels among main transformer substations are taken as constraint conditions, and a genetic algorithm is used for solving. The method disclosed by the invention fully coordinates a contact structure relationship between a high-voltage transformer substation and an inferior medium-voltage power grid and can achieve the optimal economic effect on the basis of meeting the regional load demands. The optimal solution is searched by simulating a natural evolutional process according to an artificial intelligent algorithm, namely the genetic algorithm. The problems of wrong search direction, iterative misconvergence, low approach velocity and the like often caused in solving for power distribution network contact structure optimization by a conventional algorithm can be effectively solved.

Description

technical field [0001] The invention belongs to the technical field of distribution network, and relates to network structure optimization of distribution network, in particular to a method for optimizing network structure of distribution system based on genetic algorithm. Background technique [0002] With the rapid development of urban economy, the increasing shortage of urban land (especially in super-large cities) makes the selection of substation sites and power corridors very difficult. Load demand) technical principles to plan high-voltage substations and medium-voltage distribution networks, it will be difficult to achieve a good balance between reducing the construction scale and reducing land resource consumption while meeting the load demands of various types of power users at all levels. [0003] One way to solve the above problems is to fully exploit the role of the current medium-voltage distribution network connection lines in the increasingly growing intercon...

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Problems solved by technology

[0005] Distribution network structure optimization is a complex optimization problem with multi-objective, uncertain, nonlinear and multi-stage characteristics. At present, the existing research methods mainly include the following categories: 1) Multi-scenario analysis method, through reasonable analysis 1. Predict various scenarios to judge the comprehensive optimality of the planning scheme. The defect is that the analysis results lack theoretical adaptability, and at the same time, it may cause difficulties in solving the situation where there are too many variables or scenarios; 2) The mathematical construction of uncertain information The modular programming method has the advantages of rigorous theory and accurate treatment of uncertain factors. Representative methods include stochastic programming, gray programming, fuzzy programming and blind number programming. However, when the data presents multiple uncertainties, it will Encountered problems such as difficulty in model expression; 3) Mathematical optimization method, whose core idea is to transform the network structure optimization planning problem into a general mathematical optimization model, and use traditional optimization algorithms or modern heuristic-based intelligent optimization algorithms to solve the problem, However, this type of algorithm will have problems such as slow convergence speed, weak local optimization ability, and long calculation time to varying degrees.

[0006] Xiao Jun, Guo Xiaodan, Wang Chengshan and others published "Evaluation and Simplification of Distribution Network Connection Effectiveness Based on Power Supply Capability" (Automation of Electric Power Systems, 2012, 36(8): 31-37.), proposed a connection-based Effective distribution network connection simplification method, but the effectiveness must be calculated for each contact branch, and the order of the increase or decrease of the contact branch will also affect the final result

It only gives an evaluation of the impact of the existing connections on the power supply capacity, and is only suitable for solving the problem of small-scale transformation of the current distribution network in the near future, and does not give a connection plan from the perspective of the overall planning

[0007] Ge Shaoyun, Han Jun, Liu Hong et al. published "Optimization of Contact Structure between Main Transformer Stations Based on Power Supply Capability" (Power Grid Technology, 2012,36(8):129-135.), using weighted Voronoi diagram combined with back-off optimization method Optimize the connection structure of the main transformers between stations, but only theoretically give the connection relationship between the main transformers between stations, and there is no specific number and scheme of the connection branches

Moreover, these two articles only use power supply capacity as the standard, blindly pursue the maximization of power supply capacity, and do not take into account the unit power supply capacity cost

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