| As a link in the power system that directly interacts with users,the distribution network is closely related to the quality of the user’s power supply.Compared with the transmission network,the distribution network is more prone to failure due to the complicated line conditions and causes a large number of users to lose power.By assembling various types of automation terminals in the distribution network,the topology structure of the power distribution network can be effectively optimized,the impact of faults can be reduced,the efficiency of fault line inspection can be improved,and the power supply quality can be significantly improved.The optimization of the distribution network automation terminal is to determine the type,location and optimal number of terminals installed on the feeder.It is mathematically a large-scale,numerous variable,non-continuous and non-differentiable combinatorial optimization problem.In the current investment planning of distribution network,more and more attention has been paid to how to optimize the configuration of various types of distribution network automation terminals to achieve the coordination of power quality and economy.For the optimal configuration of such distribution network automation terminals,this article takes medium-voltage overhead lines as the basic topology,and selects manual controll switches,automatic controll switches,and fault indicators as the main optimization configuration objects,considering their respective characteristics At the same stage,carry out unified optimization,and strive to minimize the power loss caused by permanent failure with limited capital investment,and improve power supply reliability.this paper first proposes a set of logical operators innovatively,and then based on this set of logical operators,establishes a power outage time function of the load caused by a fault,and builds a distribution system based on this function.A mixed integer quadratic programming model(MIQP)for optimal configuration of distribution network automation terminals is built around this function,The model aims at minimizing the loss of power outages,and the full life cycle cost is a constraint.It can fully consider the role of manual and automatic disconnect switches in power recovery and the role of fault indicators in accelerating the efficiency of fault line inspection.Compared with the non-linear model solved by heuristic algorithm and the latest MIQP model,it is proved that the model proposed in this paper is far superior to the above two models not only in the quality of the solution but also in the time of the solution.In the following examples,this paper further analyzes the characteristics of the results.Focused on the changing characteristics of a series of indicators such as the number of various types of terminals,improving efficiency,benefit-to-cost ratio,and power supply reliability when changing constraints.Sensitivity analysis is performed on four important parameters:fault line speed,terminal price,switching operation time,and failure probability.Finally,considering the fact that the load and the number of users in the distribution network are often unevenly distributed,a multi-objective model that takes into account power loss and power supply reliability.By introducing the epsilon constraint algorithm to solve the problem,the corresponding Pareto front is obtained.Compared with the traditional multi-objective algorithm NSGAII,its efficiency and quality are fully proved. |
