Mesh Planning And Reactive Power Planning Optimization Of High Voltage Distribution Networks

A high-voltage distribution network is the hub connecting a transmission network and a medium-voltage distribution network.The quality of a high-voltage distribution network will directly affect the power transmission efficiency.High voltage distribution network planning and reactive power planning will bring huge social and economic benefits.However,with the continuous expansion and rapid development of distribution network scale,distribution network planning is becoming more and more difficult for the entire planning area.In this paper,aiming at engineering application,based on the basic planning concept of "technically feasible and economically optimal",combined with relevant planning guidelines,the models and their solution methods for network planning and reactive power planning of a high voltage distribution network are proposed respectively.For high voltage distribution network planning,a global optimization model of power supply zoning and a corresponding heuristic optimization method are proposed in this paper.Firstly,based on the "N-1" security maximization of substations and high-voltage line channels,the optimal division of power supply zones is carried out in the global scope with the minimization cost of high-voltage tie-lines being considered.Secondly,a typical wiring mode is selected by using a technical and economic comparison method for each relatively independent power supply zone.In middle years,the transition from a simple wiring mode to a complex one is adopted.For reactive power planning in a high voltage distribution network,based on the relevant technical standards,a practical optimization model is presented: the goal is to maximize the net income of reactive power compensation,and the constraints involve the requirement of relevant technical standards on the total capacity of reactive power compensation,single bank capacity and bank number,voltage and power factor.According to the characteristics of a high-voltage distribution network,a power supply zoning based three-stage heuristic optimization method is proposed to reduce the scale and complexity of optimization calculation.Firstly,for each relatively independent high-voltage power supply area,the initial compensation bank number and capacity of a single node are determined successively in the order of net income from large to small.Then,considering the mutual influence of different position compensation capacity in the same power supply area,the initial planning scheme is iteratively revised.Finally,in the global scope,the planning scheme is checked by AC power flow and is further optimized and fine-tuned.On the basis of guaranteeing the global optimum or sub-optimum of a planning scheme,the proposed model and method can change the size of a distribution network from large to small and the corresponding planning method from complicated to simple,thus solving the problems of "optimization" and "practicality" for many existing planning methods.The proposed model and method can result in an ideal planning scheme by the combined use of computer coding and manual intervention.However,as long as the proposed model and method are understood,specific work can be accomplished by using general commercial software(such as power flow analysis)or even manual work only.