| In the process of electric power system reform, there is a phenomenon that a number of high energy consuming enterprises direct purchase of electricity from the electric power generation enterprises in the separation of transmission and distribution, namely "direct power purchase for the large customer". As newly sprouted things the key issues in operating mode and charging mode are still in the exploration stages of similar "hold the stones to cross the river"This thesis consists of the following parts:relevant policy background, the qualifications of the direct electricity purchasing, the impact of the direct electricity purchasing behavior patterns to the supplement, transmission and users by three party.In this paper, according to the analysis of the single supply single user, double supply single user, double supply double user and inter network distance transmission to research the possible actions and to try to prove this fact that through the arrangement and reasonable control, it is entirely possible based on the established power transmission and distribution price, by changing the supply routes to achieve the goal of reducing the cost.The difficulty of this paper is to confer the electrovalence of transmission and distribution. The grid profit changes from the margin of the sales price and Internet price in traditional to "fixed" transmission and distribution price. Behind of the electrovalence, electricity in power grid is always flowing, so the true distribution cost is an uncertain value. How to determine the price depends on many factors, especially in the presence of multiple power and electricity, is one of the main difficulty.Based on the analysis of direct power purchase for the large customer as the opportunity, to clarify the traditional electricity transmission and distribution cost, then proved that based on the rational layout, the grid enterprises established on the margin of transmission and distribution price is a feasible method to reduce cost and increase profit for himself. |