This design first according to the

This design first according to the task book to the system and line and all the load parameters, analysis of load development trend. Based on the proposed generalization of substation and line direction, and through the analysis of load data, security, economy and reliability into consideration, determine the 110 kv main connection, and then the main transformer was determined by the load calculation and power supply scope sets, capacity and model, but also determine the capacity of the station transformer and models, in according to the results of the maximum continuous working current and short circuit calculation to the selection of calibration equipment, at the same time, considering the system failure occurs, must have the corresponding protection device, thus made brief explanation to the relay protection. For the lightning overvoltage from the outside, lightning protection and grounding device are designed. Finally, the overall planning and layout are carried out, so as to complete the primary system design of 110kV substation.