18 kW DC-DC converter using push-pull inverter with lossless snubber circuits

Energy recovery snubber circuit for a dc–dc push–pull converter

“…2, which details the current Fig. 1 Comparison of snubber circuit used in [15] with the proposed circuitry a Lossless snubber circuit in [15] b Proposed snubber circuit conduction paths during M1 and M3 switch states. Figs.…”

“…The fundamental characteristics of the dc-dc push-pull converter have been extensively reviewed [1][2][3] and its dc application into many areas has been published [4][5][6][7][8][9][10][11][12][13][14][15]. In battery, super capacitor or photo voltaic source applications involving a low-input voltage with a high input current requirement, the push-pull converter is superior to the fullbridge converter owing to fewer device on-state voltage drops.…”

“…An auxiliary switch is used in this topology and the overshoot voltage is limited by correctly sizing the capacitor but the disadvantage is loss of output voltage regulation at light loads. A lossless snubber has been demonstrated [15] which allows the leakage energy to be passively recovered back to the dc source. An unintentional energy discharge path is created when the clamping capacitor voltage is larger than the dc source during periods when both switching devices are off.…”

“…Fig. 1a shows this lossless passive snubber circuit [15] and the unintentional off-state energy discharge path.…”

“…In this paper, the recovery circuit (in [15], Fig. 1a) is enhanced to overcome its undesirable snubber capacitor discharge limitations and in so doing both recovery paths utilise a common snubber reset inductor.…”