A rectifier transformer is a device that combines a transformer and a rectifier and is used to convert alternating current into direct current. There are usually two rectification methods of rectifier transformers: single-phase rectifier transformers and three-phase rectifier transformers.

• Single-phase rectifier transformer: In a single-phase rectifier transformer, the alternating current first passes through the primary coil of the transformer to produce a corresponding voltage transformation effect. The alternating current is then passed through a rectifier, usually a diode or transistor, which converts the alternating current into direct current. Single-phase rectifier transformers are mainly used in smaller-scale applications such as home electronic equipment, office equipment, etc.

• Three-phase rectifier transformer: In a three-phase rectifier transformer, the input AC power is a three-phase power supply. This type of transformer usually consists of three separate transformer coils, each connected to one phase of alternating current. The alternating current is then rectified by a rectifier, converting the three-phase alternating current into direct current. Three-phase rectifier transformers are commonly used in large industrial applications, such as power systems, steel plants, chemical plants, etc., where large amounts of DC power are required.

These rectification methods can be selected based on different needs and applications to meet the power conversion requirements in specific scenarios.