Detailed construction of substation architecture; transformers can be categorized into step-up transformers and step-down transformers based on their functions. The former is used in the sending-end substation of the power supply system, while the latter is used in the receiving-end substation. The voltage of the transformer must be consistent with the voltage of the power supply system. To maintain the required voltage under different load conditions, it may be necessary to change the tap connections of the transformer.