The function of a substation: to transmit electricity from high voltage to daily use

1、 Basic Introduction to Substation

Why do we need a transformer?

When transmitting power over long distances, the higher the voltage, the smaller the current, thereby reducing the loss of electrical energy during Transmission. Therefore, increasing the voltage is mainly to reduce energy loss. In addition, when approaching residential areas, it is necessary to lower the voltage, which not only ensures the normal operation of the equipment but also improves safety.

2. Principle of Substation (Transformer)

The basic principle of transformer transformation is to change the voltage by adjusting the number of turns of the coils on both sides of the transformer, which can be used for both boosting and lowering. After being output from the power plant, the electrical energy is first stepped up by the substation for long-distance transmission. When reaching the vicinity of the user, the voltage will be reduced according to demand and distributed to various types of users.

3. Basic structure of power system

Substations play a crucial role in the power system, mainly used to raise or lower voltage for the transmission and use of electricity. At the same time, the substation is also responsible for collecting multiple power sources and redistributing them to a large number of users, thereby improving the reliability of power supply. Due to the high voltage level handled by the substation, it also occupies a large area.

The power output from the power plant can be increased to voltage levels such as 500kV, 330kV, and 220kV through substation boosting. After a certain distance of transmission, the voltage is gradually reduced from 500kV to 330kV, 220kV, 110kV, 35kV, and finally to 10kV through a substation. However, the voltage of 10kV is still too high for daily electricity consumption. Our common community transformers further reduce the voltage of 10kV or 6kV to 380V for factory use or 220V for household use.

2、 Substation classification

1. Hub substation

The voltage ranges from 330kV to 500kV, making it a hub station in the power system.

Connect several parts of the power system, including high and medium voltage, and gather multiple power sources. After a total power outage, a large-scale power outage or system disconnection will occur, so it plays an important role in the stability and reliability of the power system.

2. Intermediate substation

The voltage level is generally 330-220KV.

Located at the interface of the main circulation line or the main trunk line of the system, it gathers 2-3 power sources and several lines. The high-voltage side mainly uses through power, while reducing voltage to supply power to regional users. After a complete power outage, it will cause the disconnection of the regional network.