Zero-voltage-transition bridgeless Boost PFC

The conducting loss of the traditional Boost power factor correction(PFC) is high, which results in the low efficiency of it, especially when the input voltage is low. According to these above, a ZVT bridgeless Boost PFC is proposed. The on off status of the switches and the main voltages and currents in one switching period are analyzed in detail. The results have shown that the main switches and the auxiliary switch have realized soft switch, and the voltage and current stresses of them is minimized. Based on these above, the condition to realize soft switch is analyzed. Finally, a prototype adopting one cycle control method is constructed, the experimental results have shown that the main switch is zero voltage on and nearly zero voltage off, the auxiliary switch is zero current on and off. The power factor is above 0.99, and the efficiency have come up to 0.96 when the input and output is normal, which have verified the correctness of the theoretical analysis.