How to reduce the voltage of transformer in substation

In modern power system, substation plays a vital role, and transformer is the core equipment to realize voltage conversion. Especially in the process of transmission and distribution, the "step-down" function of transformer is particularly critical, which ensures that power can be transmitted to thousands of households safely and efficiently. This paper will introduce how to reduce the voltage of transformers in substations.

First of all, we need to understand the basic principle of power transmission. The electric energy generated by power plants is usually about 10kV to 20kV. In order to reduce the energy loss in the transmission process, the voltage must be raised to 110kV, 220kV or even higher through a step-up transformer for long-distance transmission. However, when the power is close to the user, the high voltage must be converted into a lower voltage suitable for users, such as 10kV, 380V or 220V, etc.

So, how does the transformer step down? This mainly depends on its basic working principle-electromagnetic induction. A transformer consists of an iron core and windings, usually including a primary winding (input side) and a secondary winding (output side). When the primary winding is connected to a high-voltage power supply, an alternating magnetic field will be generated in the iron core, and the magnetic field will induce voltage in the secondary winding through electromagnetic induction.

The key of step-down transformer lies in the design of winding turns ratio. According to the direct ratio between the voltage and the number of turns of the winding, if the number of turns of the secondary winding is less than that of the primary winding, the output voltage will be lower than the input voltage, thus realizing the step-down function. For example, if the primary winding is 1000 turns and the secondary winding is 100 turns, the voltage will be reduced by 10 times.

In the substation, the step-down transformer is usually divided into multiple voltage levels, which are stepped down in turn. For example, the 220kV electric energy transmitted by the high-voltage transmission line is first reduced to 110kV or 35kV through the main transformer, then further reduced to 10kV through the next transformer, and finally reduced to 380/220V through the distribution transformer for the use of residents and industrial users.

In addition, in order to ensure the stability and safety of power supply, transformers in substations are usually equipped with voltage regulating devices. These devices can automatically adjust the output voltage according to the load change, so as to keep the voltage fluctuating within a reasonable range, thus protecting the electrical equipment and improving the power supply quality.

In a word, the transformer in the substation realizes the efficient conversion from high voltage to low voltage through the combination of scientifically designed winding turns and the principle of electromagnetic induction. It is an indispensable and important equipment in modern power system, which ensures the safe transmission and reasonable distribution of power. With the development of science and technology, future transformers will develop in the direction of intelligence and energy saving, providing support for building a more efficient and reliable power system.