| Title |
Optimal Design of GaN-FET based High Efficiency and High Power Density Boundary Conduction Mode Active Clamp Flyback Converter |
| Authors |
Chang-Min Lee ; Hyun-Su Gu ; Sang-Keun Ji ; Dong-Kyun Ryu ; Jeong-Il Kang ; Sang-Kyoo Han |
| DOI |
10.6113/TKPE/2019.24.4.259 |
| Keywords |
Active clamp flyback converter; Boundary conduction mode; GaN-FET; High power density; Optimal design |
| Abstract |
An active clamp flyback (ACF) converter applies a clamp circuit and circulates the energy of leakage inductance to the input side, thereby achieving a zero-voltage switching (ZVS) operation and greatly reducing switching losses. The switching losses are further reduced by applying a gallium nitride field effect transistor (GaN-FET) with excellent switching characteristics, and ZVS operation can be accomplished under light load with boundary conduction mode (BCM) operation. Optimal design is performed on the basis of loss analysis by selecting magnetization inductance based on BCM operation and a clamp capacitor for loss reduction. Therefore, the size of the reactive element can be reduced through high-frequency operation, and a high-efficiency and high-power-density converter can be achieved. This study proposes an optimal design for a high-efficiency and high-power-density BCM ACF converter based on GaN-FETs and verifies it through experimental results of a 65 W-rated prototype. |