Electrical part design of 110KV step-down substation
Substation is an important part of the power system, which is composed of electrical equipment and transmission network in a certain way. It obtains electric energy from the power system through its transformation, distribution, transmission and protection functions, and then safely, reliably and economically transmits the electric energy to each place where electric equipment is transferred. This design task aims to reflect the degree of mastery of knowledge in various disciplines of this specialty. First, analyze the load development trend according to the parameters of the system, line and all loads given in the task book. This paper expounds the necessity of building the substation from the aspect of load growth, and then through the summary of the proposed substation and the outgoing line direction, and through the analysis of load data, economic and reliability considerations, determines the main wiring forms of 110kV, 35kV, 10kV and station power, and then determines the number, capacity and model of the main transformers through load calculation and power supply scope, At the same time, the capacity and model of station transformer are also determined. Finally, line protection, transformer protection, bus protection and lightning protection are made according to the calculation results of maximum continuous working current and short circuit calculation