The 35KV substation refers to a high-voltage place of 35 kV. In order to transfer the power from the power plant to a remote place, the voltage must be increased to become a high-voltage power, and the voltage should be lowered as needed near the user. This lifting voltage is done by the substation. A substation is a power facility that converts voltage, receives and distributes electrical energy, controls the flow of electrical power, and adjusts voltage in a power system. It connects the voltages of the various levels of voltage through its transformer. The substation is in a specific environment; it is the AC-DC-AC conversion process. Like submarine transmission cables and long-distance transportation. Some use high voltage DC power transmission and transformation. The direct current transmission overcomes the capacitive reactance loss of the alternating current transmission. It has an energy saving effect. The main equipment and connection methods of substations vary according to their functions.