Abstract
The ac side structure of a bridgeless single-stage isolated ac–dc converter reduces the number of components by sharing power switches between the bridgeless rectifier and the dual-active-bridge (DAB) dc–dc converter. However, it also makes it more difficult to achieve zero-voltage switching (ZVS) for the ac side switches. Therefore, a modulation scheme is proposed to achieve ZVS for all switches over the full ranges of the grid voltage and load. A quasi-fixed switching frequency control method is also applied, in which the switching frequency is constant during a half-cycle of the grid voltage. By adjusting the switching frequency, the grid side inductor can operate in critical conduction mode without a zero-current-detection circuit, which facilitates the ZVS realization of the ac side switches. In addition, a natural power factor correction can be realized without the grid-side current sensors. Finally, a 500 W prototype was built to validate the theoretical analysis and the effectiveness of the proposed modulation scheme.
| Original language | English |
|---|---|
| Article number | 22113715 |
| Pages (from-to) | 195-205 |
| Journal | IEEE Transactions on Power Electronics |
| Volume | 38 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2023 |
Keywords
- AC–DC converter
- dual active bridge (DAB)
- power factor correction (PFC)
- zero-voltage switching (ZVS)