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Background
A charging module maker faced high transformer temperature rise at full load on its 30kW DC module, driving fan speed and acoustic noise up while missing the new efficiency target.
Challenges
- 100kHz switching with both core and copper loss reduced.
- No increase in transformer volume.
- 100% hi-pot testing and long-term full-load burn-in.
- High annual volume with consistent quality.
Our Solution
Low-loss power ferrite core plus litz wire winding.
- Core grade reselected for the actual flux and frequency, cutting core loss by about 20%.
- Litz wire reduces skin-effect copper loss.
- Sandwich winding lowers leakage inductance and switch voltage spikes.
- Longer creepage distance and thermally conductive epoxy improve heat paths.
Results
- Full-load efficiency up from 96.2% to 98.0%.
- Hot-spot temperature rise down 11°C.
- Over 200,000 pcs delivered per year after full validation.