Basic Principle of a 400Hz Transformer

The size of a transformer is closely related to its operating frequency. In transformer design, the core cross-sectional area is usually typically proportional to the operating frequency.
Therefore, when the operating frequency is increased from 50Hz or 60Hz to 400Hz, the required core volume can be significantly reduced.

In a typical aviation power system, the power conversion process typically includes the following steps:

• 1. Rectifying the onboard DC power supply (e.g., 28V or 270V DC) or frequency-converted AC power.
• 2. Generating a stable 400Hz AC power supply using PWM technology via an inverter.
• 3. The **400Hz transformer** performs voltage regulation (e.g., step-up to 115V/200V) and provides electrical isolation.

Through this structure, the 400Hz transformer simultaneously undertakes the important functions of **voltage transformation, system isolation, and power quality stabilization** during the power conversion process.

Magnetic Materials and Structural Optimization

To accommodate higher operating frequencies, 400Hz transformers typically employ the following materials and technologies:

• 1. Thin silicon steel sheet lamination structure (thickness approximately 0.1–0.2 mm)
• 2. Amorphous alloy core materials
• 3. Low-loss ferrite materials

These materials possess high permeability and low eddy current losses, significantly improving transformer efficiency and reducing heat generation.