How to apply rectifier transformer

Rectifier transformer is an indispensable and important equipment in power electronic system, which is widely used in various occasions that need to convert alternating current into direct current. It not only plays the role of voltage conversion, but also undertakes important functions such as electrical isolation and improving system stability. Based on the basic principle of rectifier transformer, this paper discusses its application and importance in different fields.

First, the basic principle of rectifier transformer

Rectifier transformer is a kind of transformer specially used to cooperate with rectifier. Its main function is to convert the input AC voltage into a voltage level suitable for rectifier operation, and realize the electrical isolation between AC system and DC system. Rectifier transformers usually work under nonlinear load conditions, so problems such as harmonic current, loss increase and temperature rise should be considered in design.

Second, the main application fields of rectifier transformer

1. Industrial rectifier device
In metallurgy, chemical industry and other industries, high-power DC power supply is often needed, such as electrolytic aluminum, electroplating, DC arc furnace and other occasions. The rectifier transformer and silicon controlled rectifier can convert high-voltage alternating current into low-voltage and high-current direct current to meet the needs of industrial production.

2. Traction power supply system
In urban rail transit and electric locomotives, rectifier transformers are used to convert high-voltage alternating current into voltage levels suitable for traction converters. After rectification, the electric energy is supplied to the traction motor to realize the operation of the train.

3. New energy field
In wind power generation and photovoltaic power generation systems, rectifier transformers are used to convert alternating current output by generators into direct current for energy storage or grid-connected inverter. Especially in HVDC project, rectifier transformer is one of the key equipment, which undertakes the important task of AC/DC energy conversion.

4. Ship and aviation power system
In some special applications, such as the power system of ships and aircraft, rectifier transformers are used to build a stable DC power supply network to improve the efficiency and reliability of the system.

Three, rectifier transformer selection and design points

Because the rectifier transformer works in an environment with high harmonic content, its design should pay special attention to the following aspects:

-Winding design: Additional losses caused by harmonics should be considered, and appropriate wire materials and cross-sectional areas should be adopted.
-Cooling system: In order to prevent overheating, forced air cooling or oil cooling is usually adopted.
-Insulation grade: Considering voltage fluctuation and transient overvoltage, insulation materials should have high withstand voltage.
-Voltage regulation mode: On-load voltage regulation or no-load voltage regulation structure can be selected according to the load change.

IV. Conclusion

With the development of power electronics technology, rectifier transformer plays an increasingly important role in modern industry and energy system. It not only improves the energy conversion efficiency, but also enhances the security and stability of the system. In the future, with the continuous progress of new energy, smart grid and other technologies, the application of rectifier transformer will be more extensive, and its performance will be continuously improved, making greater contributions to promoting green energy and efficient electricity use.