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In this paper, a new single-stage single-phase isolated AC-DC converter derived from a differential boost AC-DC converter is proposed. This converter eliminates the need to use the bulky electrolytic capacitor from the system and at the same time provides DC charging by employing the AC Power Decoupling waveform control method, effectively addressing the power density and reliability related issues commonly associated with the bulky electrolytic capacitor. As half of the switches of this converter act as synchronous rectifier during half grid cycle they are inherently ZVS Turned On while the remaining switches achieve ZVS Turn On as they act as synchronous rectifier during other half grid cycle. However, all diodes at the secondary side achieve ZCS Turn Off during the entire line cycle. A conventional controller is implemented for output voltage regulation and PFC control whereas a power decoupling controller is added to compensate second harmonic ripple power. Besides, an interleaving technique is applied to provide high-frequency links for transformers' connection while at the same time increasing the power range and effectively reducing the size of the input filter. Finally, the operating principle of the converter is validated through simulation, and the experimental results are provided.

In this paper a single-stage single-phase differential Current-fed isolated AC-DC converter is proposed. This converter eliminates the requirement to use bulky electrolytic capacitor from the system and at the same time provides DC charging by employing the AC Power Decoupling waveform control method. All the switches of the converter achieve ZVS turn on during half line cycle and all diodes achieve ZCS turn off during entire line cycle. A conventional controller is implemented for PFC control and output regulation, whereas a power decoupling controller is added to compensate 2nd harmonic ripple power. In addition, an interleaving technique is applied to increase the power range of the converter and reduce the input inductor size. In the end simulation verification and experimental results are obtained.

This paper proposes an active-snubber-cell and its dual circuit to achieve fully soft-switching operation for PWM DC-DC converters. Main switch of the converter achieves both turn-on and turn-off with zero voltage condition; a switch in the proposed cell achieves zero current turn-on and zero voltage turn-off. The main diode is turned-off with zero current and other semiconductor devices operate under soft-switching condition. No additional voltage and current stresses are imposed by the proposed cell. The proposed active-snubber-cell can be applied in a range of PWM DC-DC converters; the guidelines for implementing the proposed cell will be presented. Easy implementation for an interleaved converter makes the proposed cell is suitable for high power applications. The presented operating principle and analysis is verified using a 100 kHz and 1kW prototype of the proposed cell implemented on a boost converter. As a result, the peak efficiency of 98% is achieved.