This article is mainly to 220 kv step-down substation electrical part of the preliminary design, the substation is an important regional step-down substation, it mainly in the 220 kv and 220 kv power exchange between the two voltage levels, but also a certain area of the load.
Design of this paper is based on the three-phase short-circuit current calculation, on the main transformer and a variety of related electrical equipment selection and calibration (including circuit breaker, isolating switch, current transformer, voltage transformer, bus, etc.), combined with the technical conditions and the environmental conditions given on the main electrical wiring design, and mapped the substation main wiring diagram, 220 kv side profile and the floor plan, etc., initially completed the preliminary design of a system of the step-down transformer substation. Finally, the protection of lightning protection is also designed to improve the safety of power supply.