Symmetrical rectifying circuit having output current ripple cancellation function

Abstract

The invention discloses a symmetric rectifying circuit capable of counteracting output current ripples, which comprises a power transformer with four secondary side windings, two flying and balancing capacitors and two rectifier diodes. The symmetric rectifying circuit can effectively counteract the output current ripples by using the symmetric secondary side windings of the transformer and the flying and balancing capacitors without any additional active auxiliary element, so as to greatly reduce the capacitance value and volume of an output filter capacitor; and the symmetric rectifying circuit suppresses the voltage parasitic oscillation on a secondary side rectifying tube output junction capacitor, clamps the voltage stress of a rectifying tube at double output voltage, reduces the level of the withstand voltage of the rectifying tube and reduces the on-state loss of the rectifying tube. In addition, the effective reduction of the current in the secondary side windings of the transformer reduces the loss of the secondary side windings. Therefore, the symmetric rectifying circuit can effectively improve the overall conversion efficiency and the power density of the transformer while taking production cost into consideration.

Description

technical field [0001] The invention belongs to the field of DC / DC conversion and rectification, and relates to a rectification circuit capable of realizing output current ripple cancellation and low rectifier tube voltage stress. More specifically, the present invention relates to a rectifier circuit comprising a power transformer with four secondary side windings and two flying balance auxiliary capacitors. Background technique [0002] Full wave capacitive rectification circuit ( figure 1 ) is widely used in high-current output occasions due to its simple structure, low rectifier voltage stress, no output inductance loss, and easy realization of the soft-switching working environment of the rectifier. However, the high-frequency power transformer leakage inductance and lead inductance and the equivalent parasitic output junction capacitance of the secondary side rectifier can easily generate voltage parasitic oscillations during commutation, which increases the voltage s...

AI Technical Summary

Problems solved by technology

But in the case of high current, the output current ripple is still enough to affect the volume and loss of the output filter capacitor

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