Substation is an important part of

Substation is an important part of the power system, it directly affects the safety and economic operation of the whole power system, is the intermediate link between power plants and users, plays the role of transformation and distribution of electric energy.This design takes the 110kV step-down substation as the main design object, analyzes the original data of the substation, determines the main wiring of the substation, and determines the number, capacity and model of the main transformer through load calculation. According to the results of short circuit calculation, the primary equipment of substation is selected and checked. At the same time, the design of lightning protection and grounding device is completed.Key words: substation electrical main wiring; short circuit current calculation; primary equipment; lightning protectionThis design topic is the primary system design of 110kV substation. This design task aims to reflect the degree of mastering the knowledge of each subject of the major, cultivate the ability of comprehensive application of the knowledge of each subject of the major, and test the learning results of the major in the past three years.