Research On Two Level Optimization Model For Electric Universal Service Based On Cross Subsidy

With the deepening of the new round of power system reform,the study of electric universal service needs to be advanced.On the one hand,the technical implementation path of China's electric universal service is worthy of discussion,and there is room for adjustment of the existing path.On the other hand,the power grid companies responsible for the universal service of electric power will face more and more prominent cross-subsidy problems,and the related cost recovery is difficult.Research on the implementation path and cost recovery mechanism of electric universal service has theoretical and practical significance.Firstly,we discuss the supply and demand model of the electric universal service.From the policy perspective and statistical perspective,the study has obtained macro and micro coverage of electric universal service implementation.This paper analyzes the economic law of the electric universal service under the conditions of administration and marketization,and demonstrates the risk of the electric universal service supply delaying and the loss risk of the grid companies.On the basis of the classical theory of social welfare function,the electric consumption Engel coefficient is introduced,and the functional relationship between the comprehensive social welfare and the electric consumption Engel coefficient is obtained,then the quantitative modeling of the optimal demand for electric universal service is realized.Secondly,a two-layer microgrid optimization model for electric universal service is established.In order to study the microgrid composition of electric universal service in remote areas,the objective unction is proposed to minimize both the electric cross-subsidy cost and reliability loss,and distinguish village microgrid from regional microgrid.Specifically,the load requirements of microgrid are calculated on the basis of introducing the optimal demand of electric universal service.By solving the Mixed Integer Linear Programming problem,the village microgrid wiring diagram and power supply configuration based on the demand nodes in the village are obtained.Taking the village as the node,the regional microgrid is formed by connecting the medium voltage line,and the wiring diagram and power supply configuration are optimized.In the example composed of 5 villages,the optimal selection of the implementation scheme of electric universal service in remote areas is realized by calculating and comparing the cross-subsidy and reliability loss difference.Finally,the price mechanism of the electric universal service is studied.It is proved that the extension of the main network is easy to fall into the inefficient A-J dilemma.By measuring the leveling power supply cost and the distortion degree of the electricity price,it is found that the distance from the assisted area to the main network is 19.6km,which is the boundary point between the off-grid microgrid mode and the main network extension mode in five village examples.By discussing the influence of load optimal demand,energy storage cost and energy storage life on the degree of price distortion,it is concluded that the energy storage cost is the key factor affecting the price distortion of microgrid in the electric universal service.From the point of view of reducing price distortion,this paper puts forward the mechanism that civil and commercial supply of electric universal service funds.On the basis of measuring the distortion of electricity price,the proportion of residential users and commercial users is obtained,and the policy recommendations are given in order to provide solutions for the implementation and cost recovery of electric universal service.