| Under the premise of ensuring that the distribution network is still strong and reliable,it has an important influence on the development and transformation of the power grid by limiting the over-construction investment of the distribution network and making accurate and efficient investment.Distribution network planning determines the scale of investment in distribution network construction in the future,so how to make a comprehensive assessment for the economy and reliability of distribution network planning scheme has become an urgent problem to be solved.The purpose of this paper is to construct a comprehensive evaluation model of distribution network planning scheme to evaluate the advantages and disadvantages between distribution network planning schemes and the rationality of the scheme itself.In this paper,the tatal cost in of distribution network is divided into two parts:the cost of power supply and the cost of power shortage.Among them,the power supply cost partially uses the pricing method of transmission and distribution price to account for the planned electricity price of the investment scale of the annual reaction planning scheme at all levels in the planning area.The cost of power shortage,using fault enumeration method,constructs comprehensive user power shortage loss function to calculate the price of electricity without electricity in order to reflect the loss caused by the lack of reliability of the distribution network built in accordance with the planning scheme in each level of the year.Based on the idea of system dynamics,the calculation model of planning electricity price and electricity shortage price is constructed,and they are combined to evaluate electricity price to form a complete set of comprehensive evaluation model.There will be differences in the annual assessment of electricity prices at different levels under different planning schemes,and the advantages and disadvantages of the schemes can be judged accordingly.At the same time,the future theoretical electricity price development level of the planning area is predicted by the elastic coefficient method,and the forecast electricity price is compared with the evaluation electricity price to judge whether the scheme itself is reasonable enough.By selecting two different sets of planning scheme examples of a power grid in a local distribution grid planning,this paper accounts for its evaluation of electricity price and forecasted electricity price of every level year,so as to make a comprehensive assessment of the two schemes,make sensitivity analysis to evaluate electricity price and verify the correctness and feasibility of the comprehensive evaluation model for the distribution network planning scheme established in this paper.This method can make the investment of distribution network more reasonable,alleviate the excessive and advance construction of power grid,and help to reduce this saving in the distribution network planning process,meet the needs of reducing the cost of social energy use,and ensure the sustainable development of the power grid. |
