A Wide Load Range ZVS Push–Pull DC/DC Converter With Active Clamped

Design, modelling, and implementation of a modified double‐switch flyback‐forward converter for low power applications

“…where i L and i Lm are the instantaneous inductor current and the instantaneous magnetising inductance of the transformer, respectively. The average current of each capacitor in a steady state can be calculated by (14) and (15)…”

“…The average input current over one period can be shown by (19). Also, the DC equivalent circuit can be determined by using (1)-(5), (14) and (15), as shown in Fig. 4.…”

“…Furthermore, the isolated converters can handle multi-output with different voltage value. Five main isolated DC/DC converters are as follows: the flyback [5][6][7][8][9][10][11], forward [12][13][14], push-pull [15], half-bridge [16], and full-bridge converters [17][18][19][20][21][22]. The manufacturing cost, the power transfer capability and the rated voltage and current of the desired converter usually limit our selection between the above topologies.…”

Magnetising‐current‐assisted wide ZVS range push–pull DC/DC converter with reduced circulating energy

“…However, the conventional push-pull converter operates at hard switching resulting in high switching losses and producing high-voltage spike across the devices, which leads to demanding high-voltage rating switches and the problem of EMI with the increase of switching frequency [7]. In order to release these drawbacks, many zerovoltage-switching (ZVS) or zero-current-switching push-pull topologies have been proposed in past decades [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], where their soft switching is mostly realised by using the series, parallel or series-parallel resonance between the added or inherent resonant inductors and parasitic capacitors.…”

“…A more severe problem is high-voltage spike during the switching transient resulting from leakage inductance of the highfrequency (HF) transformer. Different passive snubber [16], energy recovery circuits [17,18] and active snubbers [19][20][21][22][23][24][25] have been discussed to suppress the voltage spike. The snubber capacitor voltage in [16] is higher than the input voltage and the duty ratio has to be fixed 0.5 to block the unintentional current path.…”