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US 2018/0123480 A1Published application
Enhanced flyback converter
OwnerJin Wang, Xuan Zhang +1inventors
InventorsJin Wang, Xuan Zhang, Ke Zou
Life of this patent
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Abstract
A DC/DC flyback converter that exhibits reduced switch and transformer voltage stresses in comparison to known flyback converters. The flyback converter also employs soft switching. Embodiments of such flyback converters may be used, without limitation, in electric vehicles and hybrid electric vehicles. A front-stage of the flyback converter comprises a DC/AC step-down circuit that may be separately used for various purposes.
Claims24
A flyback DC/DC converter, comprising:
- a circuit having a high-voltage side and a low-voltage side separated by a transformer;
- a plurality of switches on the high-voltage side and a plurality of switches on the low-voltage side;
- a plurality of components that are adapted to store energy in an electric field on the high-voltage side, and at least one such component on the low-voltage side;
- at least one component that is adapted to store energy in a magnetic field on the low-voltage side;
- wherein, the switches are actuatable in various combinations at a selected switching frequency to produce both active modes and deadband modes of operation within a given switching period;
- and
- wherein the at least one component that stores energy in a magnetic field is adapted to store energy only in active modes when an associated high-voltage side switch is turned on, and to release energy to a load only in deadband modes when the associated high-voltage side switch is turned off.
4 more elements
A flyback DC/DC converter, comprising:
- a circuit having a front-stage side and a post-stage side separated by a transformer, the front-stage side adapted for connection to an input voltage source;
- a plurality of components that store energy in an electric field on the front-stage side, and at least one such component on the post-stage side;
- at least one component that stores energy in a magnetic field on the post-stage side;
- and
- a plurality of switches located on both the front-stage side and the post-stage side, the switches being actuatable in various combinations and at a selected switching frequency within a given switching period;
- wherein, in steady-state operation, the voltage stress on the switches is about ⅔ of the input voltage and the voltage stress on the transformer is about ⅓ of the input voltage;
- and
- wherein the post-stage side switches exhibit zero current switching during both turn-on and turn-off thereof, and the front-stage side switches exhibit zero current switching during turn-on thereof.
5 more elements
A method of performing DC/DC power conversion, comprising:
- (a) providing a flyback DC/DC converter circuit, comprising:
- a high-voltage side in the form of a step-down DC/AC circuit that is adapted for connection to an input voltage source and has a step-down ratio of approximately 3:1, and a low-voltage side selected from the group consisting of a traditional rectifying circuit and a ripple cancelling circuit, the high-voltage side and the low-voltage side separated by a transformer,
- a plurality of switches on the high-voltage side and a plurality of switches on the low-voltage side,
- a plurality of components that are adapted to store energy in an electric field on the high-voltage side, and at least one such component on the low-voltage side, and
- at least one component that is adapted to store energy in a magnetic field on the low-voltage side;
- (b) actuating the switches in various combinations at a selected switching frequency to produce both active modes and deadband modes of operation within a given switching period;
- and
- (c) causing the at least one component that stores energy in a magnetic field to store energy only in active modes when an associated high-voltage side switch is turned on, and to release energy to a load only in deadband modes when the associated high-voltage side switch is turned off;
- such that, in steady-state operation, the voltage stress on the switches is about ⅔ of the input voltage and the voltage stress on the transformer is about ⅓ of the input voltage.
6 more elements
Dependencies are inferred from the claim text.