Abstract:In order to make use of information and data resources such as transmission and distribution price reform, distribution network and user load characteristics, and to provide users with comprehensive and refined power supply services, and in view of the demand of high energy-consuming enterprises to reduce the cost of power consumption by choosing high-level voltage-level power grid, this paper analyses the technical principles, requirements and electricity cost elements of selecting high level voltage grade power supply for upgrading voltage.At the same time, the economic evaluation model of large consumer access grid voltage level selection and economic evaluation models for technological upgrading of large users is proposed, and the economic evaluation of high energy consumption Enterprises'' technological upgrading typical projects in Guizhou province is carried out. Under the current transmission and distribution price in Guizhou province, when the annual average electricity consumption of the consumer is more than 120 million kWh, the static investment recovery period of the consumer power supply from the 35kV technical transformation to 110kV is less than 5 years, and the technical upgrading project has economic benefit.When the annual average electricity consumption of the consumer is more than 1 billion kWh, the static investment recovery period of the consumer power supply from the 110kV technical transformation to 220kV is less than 5 years, and the technical upgrading project has economic benefit.