ZVS PWM converter-utilizing partial resonance

Fixed-frequency PWM (pulse-width modulation) zero-voltage switching (ZVS) conversion was realized by applying partial resonance to the forward converter. The advantages of this technique are less EMI (electromagnetic interference) and power dissipation in the switching transistor, the ability to utilize a conventional PWM control method, ease of suppression of the EMI influence due to fixed-frequency operation, and suppressed voltage-stress on the switching transistor. The hybrid converter has the advantages of both ZVS resonant and PWM converters. The converter achieves excellent efficiency: 86% at 5 V 20 A output, DC 48 V input. A wide input voltage range (18-60 DC, 85-265 V AC) and a high level of responsiveness are also achieved.<
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