Energy recovery snubber
AssigneeTDK-Lambda UK Limited
InventorsAndrew John Skinner, Atul Abhyankar
Life of this patent
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Abstract
An energy recovery snubber circuit for a power converter which includes a flyback transformer driven by a converter switch is disclosed. The snubber circuit includes two capacitors which are connected such that, when the snubber circuit is connected to a primary winding of the flyback transformer, the capacitors are charged in series by current flowing in a first direction in the primary winding when the converted switch is turned OFF, to recover energy stored in the leakage inductance of the transformer, and discharged in parallel to cause current flow in a second direction in the primary winding of the transformer, to thereby transfer the recovered energy to the transformer.
Claims19
An energy recovery snubber circuit for a power converter which comprises a flyback transformer driven by a converter switch,
- the snubber circuit comprising first and second capacitors which are connected such that, when the snubber circuit is connected to a primary winding of the flyback transformer, the capacitors are:
- charged in series by current flowing in a first direction in the primary winding when the converter switch is in an off-state, to recover energy stored in the leakage inductance of the transformer;
- and
- discharged in parallel to cause current flow in a second direction in the primary winding of the transformer, to thereby transfer the recovered energy to the transformer,
- the snubber circuit further comprising at least one snubber switch configured to controllably complete first and second paths by which the first and second capacitors, respectively, discharge via at least part of the primary winding of the transformer.
A power converter which comprises:
- a flyback transformer driven by a converter switch;
- and
- an energy recovery snubber circuit, the snubber circuit comprising:
- first and second capacitors connected in series to a primary winding of the transformer via a first rectifier, and connectable in parallel to the primary winding via second and third rectifiers and a snubber switch,
- such that, when the converter switch is in an off-state, current flowing in a first direction in the primary winding of the transformer flows through the snubber circuit via the first rectifier, to charge the first and second capacitors in series, and thereby recover energy stored in the leakage inductance of the transformer,
- and such that the snubber switch is configured to controllably complete first and second paths by which the first and second capacitors, respectively, discharge via at least part of the primary winding of the transformer, thereby causing current flow in a second direction in the primary winding of the transformer and transferring the recovered energy to the transformer.
Dependencies are inferred from the claim text.