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EP-4740297-A1 - LLC RESONANT CONVERTER ARRANGEMENT

EP4740297A1EP 4740297 A1EP4740297 A1EP 4740297A1EP-4740297-A1

Abstract

LLC resonant converter arrangement (10, 32), comprising: a first module (12) with a first primary side (16, a first secondary side (18), and a first resonant circuit (20) coupling the first primary side (16) with the first secondary side (18), a second module (14) with a second primary side (22), a second secondary side (24), and a second resonant circuit (26) coupling the second primary side (22) with the second secondary side (24), a center-tapped capacitor (Co1Co2) arranged between a DC output side of the first secondary side (18) and a DC output port (28) of the LLC resonant converter arrangement (10, 32), wherein the DC output side is connectable to a DC input side of the center-tapped capacitor (Co1Co2) by a first switch (S1), a DC output side of the second secondary side (24) is connectable to the DC input side of the center-tapped capacitor (Co1Co2) downstream of the first switch (S1) by a second switch (S2), and a center tap point of the center-tapped capacitor (Co1Co2) is connectable to a center tap point of one of the half bridges of the first secondary side (18) by a third switch (S5).

Inventors

  • Ayad, Ayman
  • MARANGATTU PRINCE, Aswathy

Assignees

  • Schaeffler Technologies AG & Co. KG

Dates

Publication Date
20260513
Application Date
20240613

Claims (10)

  1. 1. LLC resonant converter arrangement (10, 32) for DCDC conversion, comprising: a first module (12) with a first primary side (16) including two half-bridges, a first secondary side (18) including two half-bridges, and a first resonant circuit (20) coupling the first primary side (16) with the first secondary side (18), a second module (14) with a second primary side (22) including two half-bridges, a second secondary side (24) including two half-bridges, and a second resonant circuit (26) coupling the second primary side (22) with the second secondary side (24), a center-tapped capacitor (Co1 Co2) arranged between a DC output side of the two half-bridges of the first secondary side (18) and a DC output port (28) of the LLC resonant converter arrangement (10, 32), wherein the DC output side of the two half-bridges of the first secondary side (18) is connectable to a DC input side of the center-tapped capacitor (Co1 Co2) by a first switch (S1 ), a DC output side of the two half-bridges of the second secondary side (24) is connectable to the DC input side of the center-tapped capacitor (Co1 Co2) downstream of the first switch (S1 ) by a second switch (S2), and a center tap point of the center-tapped capacitor (Co1 Co2) is connectable to a center tap point of one of the two half bridges of the first secondary side (18) by a third switch (S5).
  2. 2. LLC resonant converter arrangement (10, 32) of claim 1 , further comprising: a control unit (30) configured for controlling the first switch (S1 ) into a closed state and the third switch (S5) into an open state for operation the first module (12) in a normal operation, and controlling the third switch (S5) from an open state into a closed state in case of a fault in one of the two half-bridges in the first primary side.
  3. 3. LLC resonant converter arrangement (10, 32) of claim 2, wherein the control unit (30) is further configured for determining a failure of the first module (12) and controlling the first switch (S1 ) and the third switch (S5) into an open state and the second switch (S2) into a closed state in response to the determined failure of the first module.
  4. 4. LLC resonant converter arrangement (10, 32) of any one of claims 2-3, wherein the control unit (30) is further configured for controlling the second switch (S2) in a closed state in case additional power is required at the DC output port (28) of the LLC resonant converter arrangement (10, 32).
  5. 5. LLC resonant converter arrangement (34, 42) for DCDC conversion, comprising: a first module (12) with a first primary side (16) including two half-bridges, a first secondary side (18) including a B6C rectifier circuit including three half-bridges, and a first resonant circuit (20) coupling the first primary side (16) with the first secondary side (18), a second module (14) with a second primary side (22) including two half-bridges, a second secondary side (24) including two half-bridges, and a second resonant circuit (26) coupling the second primary side (22) with the second secondary side (24), and a capacitor (Co) arranged between a DC output side of the B6C rectifier circuit and a DC output port (28) of the LLC resonant converter arrangement (34, 42, 44), wherein the DC output side of the two half-bridges is connectable to a DC input side of the capacitor (Co) by a first switch (S1 ), a DC output side of the two half-bridges of the second secondary side (24) is connectable to the DC input side of the capacitor (Co) downstream of the first switch by a second switch (S2), a secondary winding of a transformer (Tr1 ) of the first resonant circuit (20) includes a first winding end port (36), a second winding end port (38) and a winding center tap port (40), wherein the first winding end port (36) is connected to a center tap point of a first half-bridge of the three half-bridges, the winding center tap port (40) of the secondary winding is connectable to a second half-bridge of the three half-bridges by a third switch (S8), and the second winding end port (38) is connectable to a center tap point of a third half-bridge of the three half-bridges by a fourth switch (S7).
  6. 6. LLC resonant converter arrangement (34, 42) of claim 5, comprising: a control unit (30), wherein the control unit (30) is configured for controlling the first switch (S1 ) into a closed state, the third switch (S8) into a closed state and fourth switch (S7) into an open state in case of normal operation of first module (12), and controlling the third switch (S8) from a closed state into an open state and the fourth switch (S7) from an open state into a closed state in case of a fault in one of the half-bridges in the first primary side (16).
  7. 7. LLC resonant converter arrangement (34, 42) of claim 6, wherein the control unit (30) is further configured for determining a failure of the first module (12) and controlling the first switch (S1 ) into an open state and the second switch (S2) into a closed state in response to the determined failure of the first module.
  8. 8. LLC resonant converter arrangement (34, 42) of any one of claims 6-7, wherein the control unit (30) is further configured for controlling the second switch (S2) in a closed state in case additional power is required at the DC output port (28) of the LLC resonant converter arrangement (34, 42).
  9. 9. LLC resonant converter arrangement (10, 32, 34, 42) of any one of the preceding claims, wherein the two half bridges of the first secondary side (18) and/or the second secondary side (24) are passive half-bridges, preferably diodes.
  10. 10. LLC resonant converter arrangement (10, 32, 34, 42) of any one of the preceding claims, wherein the first primary side (16) and the second primary side (22) are connected in series or in parallel.

Description

Description LLC resonant converter arrangement The present invention relates to a LLC resonant converter arrangement for DCDC conversion. In particular, the present invention relates to a stand-alone fault-tolerance integrated fully-redundant LLC resonant converter arrangement for HV/LV DCDC conversion, in particular for use in the automotive sector. The present invention further relates to a method of operating such an arrangement. Fail-operational is paramount, in a particular in powertrains related to e-mobility applications, but also in autonomous driving applications ensuring safety, reliability, and compliance with regulations. The implementation of a fail-operational mechanism can be accomplished through either redundancy or through an independent fault-tolerant capability. The reliability of power electronic converters is of significance in mission-critical applications, including electric vehicles, aerospace systems, and other safety related applications. When it comes to e-mobility, stand-alone fault-tolerant and fully-redundant HV/LV DCDC converters are essential for the safe and reliable operation of autonomous systems, particularly in advanced autonomous driving (AD) L4/L5 vehicles. Fault-tolerant and redundant HV/LV DCDC converters ensure consistent power conversion and enhance system resilience by providing backup power paths. Current designs of HV/LV DCDC converter arrangements, however, provide either a fault-tolerance capability or a redundancy capability. It is thus an object of the present invention to provide an HV/LV DCDC converter arrangement, or more generally an LLC resonant converter arrangement which provides a stand-alone fault-tolerance integrated fully-redundant concept that provides both a stand-alone fault-tolerance and fully-redundant capability. This and other objects, which become apparent upon reading the description, are solved by the subject-matter of the independent claims. Further embodiments and developments are provided in the dependent claims. According to a first aspect of the present invention, a LLC resonant converter arrangement for DCDC conversion, in particular for HV/LV DCDC conversion, is provided. The arrangement comprises a first module with a first primary side including two half-bridges, a first secondary side including two half-bridges, and a first resonant circuit coupling the first primary side with the first secondary side; a second module with a second primary side including two half-bridges, a second secondary side including two half-bridges, and a second resonant circuit coupling the second primary side with the second secondary side; and a center-tapped capacitor arranged between a DC output side of the two half-bridges of the first secondary side and a DC output port of the LLC resonant converter arrangement. In the arrangement, the DC output side of the two half-bridges of the first secondary side is connectable to a DC input side of the center-tapped capacitor by a first switch, a DC output side of the two half-bridges of the second secondary side is connectable to the DC input side of the center-tapped capacitor downstream of the first switch by a second switch, and a center tap point of the center-tapped capacitor is connectable to a center tap point of one of the two half bridges of the first secondary side by a third switch. The present invention is based at least partially on the idea that such a topology can provide both a fully-integrated redundancy as well as a stand-alone fault-tolerant capability. The redundancy aspect is taken care of a second module which can be used as back-up or top-up for the first module. The second module can be plugged in using the second switch. The stand-alone fault-tolerant aspect is taken care of a center-tapped capacitor which is connectable at a center tap point to mitigate, for example, faults in one of the switching elements of the two half-bridges in the first primary side. Altogether this topology enables a high-quality, reliable, and functionally safe DCDC conversion, in particular HV/LV DCDC conversion. Preferably, the two half-bridges of the first and/or second secondary side are passive half-bridges. Preferably, these half-bridges use diodes as switching elements. Passive half-bridges or in particular diodes are best suited for redundancy and fault-tolerant capabilities as such components are reliable and do not need active controlling. Preferably, the first primary side and the second primary side are connected in series or in parallel. Input-parallel output-parallel (IPOP) systems cater to applications requiring large output currents, while input-serial output-parallel (ISOP) systems are suited for cases with high input voltages and lower output voltages. Both topologies are well suited, in particular for applications in the automotive sector. Preferably, the LLC converter arrangement further comprises a control unit configured for controlling the first switch into a closed state and the