Technical Guide on Amorphous Alloy Dry-Type Transformers

1. Core Concepts and Structural Features

Amorphous alloy dry-type transformers are power transformers that utilize amorphous alloy materials (e.g., Fe-Si-B systems) as their magnetic cores, combined with a "dry-type" insulation design (no oil or liquid dielectric). Key structural characteristics include:

• Amorphous Alloy Core: Produced via rapid solidification, the disordered atomic structure of amorphous alloys grants superior magnetic properties, such as low coercivity, high permeability, and minimal core losses (eddy current and hysteresis losses) at high frequencies.
• Dry-Type Insulation: Epoxy resin or vacuum pressure impregnation (VPI) ensures winding insulation, eliminating fire and leakage risks associated with oil-immersed transformers. This makes them ideal for safety-critical applications like data centers and high-rise buildings. Typical designs feature laminated amorphous alloy cores (e.g., E- or C-shaped) with copper/aluminum windings. The core thickness (20–30 μm) significantly reduces energy dissipation during magnetic domain transitions.

2. Key Advantages of Amorphous Alloy Materials

The performance of amorphous alloy cores directly determines transformer efficiency and reliability:

• Ultra-Low Losses: Eddy current losses in amorphous alloys are 1/5–1/10 those of conventional silicon steel, reducing no-load losses by 60–80%. For example, a 5 kVA amorphous high-frequency transformer maintains stable core losses even at 4.5 kHz.
• High Saturation Flux Density: With a saturation flux density (${�}_{�}$) of 1.5–2.0 T, amorphous alloys outperform ferrites (0.3–0.5 T), enabling high-power (>10 kW) and medium-to-high-frequency (<100 kHz) applications.
• Thermal Stability: High Curie temperatures and minimal magnetic degradation under heat ensure durability during prolonged high-load operations.

3. Technical Benefits and Applications

Amorphous alloy dry-type transformers excel in diverse fields:

• Energy Efficiency: Exceptionally low no-load losses make them ideal for urban grids with fluctuating loads, reducing lifecycle costs.
• Environmental Safety: Dry insulation avoids oil pollution, aligning with green building standards. The production of amorphous alloys consumes 80% less energy than silicon steel.
• High-Frequency Compatibility: Paired with wide-bandgap semiconductors (SiC/GaN), they support power electronic transformers (PET), renewable energy systems (e.g., PV inverters), and high-frequency DC-DC conversion in EV charging stations.
• Noise Reduction: Lower magnetostriction compared to silicon steel reduces operational noise by 10–15 dB under normal conditions, though vibration control is critical under non-sinusoidal excitation (e.g., square waves).

4. Comparison with Conventional Transformers

5. Technical Challenges and Research Progress

Despite their advantages, challenges remain:

• High-Frequency Losses & Cooling: Core losses escalate sharply above 10 kHz, necessitating liquid or forced-air cooling. Edge losses post-core cutting also require mitigation.
• Mechanical Brittleness: Processing amorphous ribbons demands optimized annealing to reduce internal stress.
• Noise Under Non-Sinusoidal Excitation: Vibration acceleration triples under rectangular-wave excitation (duty cycle 0.6), requiring advanced magnetostriction measurement and structural redesign. Recent Advances:
• Material Innovation: Nanocrystalline alloys (e.g., Fe-Cu-Nb-Si-B) enhance high-frequency performance (${�}_{�}>1.2$ T) with improved manufacturability.
• Integrated Design: Multi-physics simulations (magnetic-thermal-mechanical) optimize winding layouts and insulation for higher power density.

6. Future Trends

• High-Frequency Miniaturization: Coupled with wide-bandgap semiconductors, operating frequencies may reach MHz levels, enabling compact, high-power-density designs.
• Smart Monitoring: Embedded sensors for real-time temperature and vibration tracking, enabling predictive maintenance.
• Sustainability: Recyclable amorphous alloys to reduce lifecycle carbon footprints.

Amorphous alloy dry-type transformers, with their unmatched efficiency, safety, and eco-friendliness, are pivotal in smart grids and renewable energy systems. Advances in materials and power electronics will further enhance their high-frequency performance, accelerating progress toward carbon neutrality