Dc-dc converter and method for controlling a dc-dc converter
AssigneeRobert Bosch GmbH
InventorEmiliano Gudino Carrizales
Life of this patent
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Abstract
The present invention relates to a DC-DC converter and to a method for controlling a DC-DC converter with high dielectric strength and reduced power losses. An optimized control of a potential-isolating multi-level half-bridge converter according to a phase-shifted full-bridge configuration with a novel modulation method is proposed.
Claims12
A DC-DC converter (1), comprising
- a first input connection (E1);
- a second input connection (E2);
- a first switching element (S1) which is arranged between the first input connection (E1) and a first node point (K1);
- a second switching element (S2) which is arranged between the first input connection (E1) and a second node point (K2);
- a third switching element (S3) which is arranged between the first node point (K1) and the second input connection (E2);
- a fourth switching element (S4) which is arranged between the second node point (K2) and the second input connection (E2),
- freewheeling diodes (D1-D4) arranged parallel to each of the switching elements (S1-S4);
- a transformer (T) with a primary side and a secondary side, wherein a first connection of the primary side is electrically coupled to the first node point (K1) and a second connection of the primary side is electrically coupled to the second node point (K2);
- a first inductance (L1) positioned between a first connection of the secondary side of the transformer (T) and a third node point (K3);
- a rectifier circuit (10) configured to rectify an electrical voltage which is applied between the third node point (K3) and a second connection of the secondary side of the transformer and to provide the rectified voltage between a first output connection (A1) and a second output connection (A2);
- and
- a control device (20) configured
- to open the second switching element (S2) and the third switching element (S3);
- to close the first switching element (S1) and the fourth switching element (S4);
- to subsequently open the fourth switching element (S4) after a predetermined first time period (t1);
- to then open the first switching element (S1) once an electric current through the first switching element (S1) and/or an electric current through the secondary side of the transformer (T) fall/falls below a prespecified threshold value;
- to subsequently close the second switching element (S2) and the third switching element (S3) after a predetermined second time period (t2);
- to subsequently open the third switching element (S3) after the predetermined first time period (t1);
- to then open the second switching element (S2) once an electric current through the second switching element (S2) and/or an electric current through the secondary side of the transformer (T) fall/falls below the prespecified threshold value.
A method (100) for controlling a DC-DC converter (1), comprising a first input connection (E1), a second input connection (E2), a first switching element (S1) which is arranged between the first input connection (E1) and a first node point (K1), a second switching element (S2) which is arranged between the first input connection (E1) and a second node point (K2), a third switching element (S3) which is arranged between the first node point (K1) and the second input connection (E2), a fourth switching element (S4) which is arranged between the second node point (K2) and the second input connection (E2), wherein a freewheeling diode (D1-D4) is arranged parallel in relation to each of the switching elements (S1-S4), a transformer (T) with a primary side and a secondary side, wherein a first connection of the primary side is electrically coupled to the first node point (K1) and a second connection of the primary side is electrically coupled to the second node point (K2), a first inductance (L1) which is arranged between a first connection of the secondary side of the transformer (T) and a third node point (K3), a rectifier circuit (10) which is designed to rectify an electrical voltage between the third node point (K3) and a second connection of the secondary side of the transformer (T), and to provide the rectified voltage between a first output connection (A1) and a second output connection (A2), wherein the method comprises:
- opening (110) the second switching element (S2) and the third switching element (S3);
- closing (120) the first switching element (S1) and the fourth switching element (S4);
- opening (130) the fourth switching element (S4) once the fourth switching element (S4) has been closed for a predetermined first time period (t1);
- monitoring (140) an electric current through the first switching element (S1) and/or an electric current through the secondary side of the transformer (T);
- opening (150) the first switching element (S1) once the monitored electric current through the first switching element (S1) and/or through the secondary side of the transformer (T) is smaller than a prespecified threshold value;
- closing (160) the second switching element (S2) and the third switching element (S3) once the first switching element (S1) has been open for a predetermined second time period (t2);
- opening (170) the third switching element (S3) once the third switching element (S3) has been closed for the predetermined first time period (t1);
- monitoring (180) an electric current through the second switching element (S2) and/or an electric current through the secondary side of the transformer (T);
- and
- opening (190) the second switching element (S2) once the monitored electric current through the second switching element (S2) and/or through the secondary side of the transformer (T) is smaller than the prespecified threshold value.
Dependencies are inferred from the claim text.