Electric Design of 35kV Substation

This paper made a design about a 35/10kV step-down substation according to the load of a town. The main technical focus is the primary electrical part design and a small part of the secondary design in the transformer design. Firstly, the volume and size of the main transformer are determined according to the original load data and considering the total load and on-site conditions in the next 5-10 years. Then, the main electrical connection method is selected according to the load grade and the status of load inlet and outlet. Then, according to the general operation principle of electrical equipment, select the main line equipment, such as circuit breaker, disconnector, fuse device, voltage transformer, current transformer, lightning protection device, etc. This design aims at the three-phase short circuit in the infinite power supply system. The electrical equipment is calibrated with three-phase short-circuit current. The calibration contents of three-phase short-circuit current are mainly dynamic stability verification and thermal stability verification.