Converter System for Transferring Power

Abstract

A converter system for transferring power including a first converter unit, a second converter unit and a control unit. The first converter unit and the second converter unit are connected in parallel. The first converter unit is connected to a high voltage system via a first series switch unit and the second converter unit is connected to the high voltage system via a second series switch unit. The first converter unit is connected to a low voltage system via a third series switch unit and the second converter unit is connected to the low voltage system via a fourth series switch unit. The control unit is configured to disconnect the first series switch unit and high voltage system in case of a failure in the first converter unit or to disconnect the second series switch unit and high voltage system in case of a failure in the second converter unit.

Claims

1. A converter system for transferring power, comprising: a first converter unit, a second converter unit, and a control unit, the first converter unit and the second converter unit being connected in parallel, the first converter unit being connected to a high voltage system via a first series switch unit and the second converter unit being connected to the high voltage system via a second series switch unit, the first converter unit being connected to a low voltage system via a third series switch unit and the second converter unit being connected to the low voltage system via a fourth series switch unit, and the control unit being configured to disconnect the first series switch unit and the high voltage system in case of a failure in the first converter unit or to disconnect the second series switch unit and the high voltage system in case of a failure in the second converter unit.

2. The converter system according to claim 1, further comprising a third converter unit, the third converter unit being connected to each of the first and the second converter units in parallel, and the third converter unit being connected to each of the high voltage system and the low voltage system directly.

3. The converter system according to claim 2, the third converter unit comprising a low power isolated DC-DC converter.

4. The converter system according to claim 2, the low power isolated DC-DC converter being a flyback converter configured to operate as a transformer.

5. The converter system according to claim 1, the first, second, third and/or fourth series switch unit comprising a power semiconductor switch element.

6. The converter system according to claim 5, the power semiconductor switch element being a MOSFET (metal oxide semiconductor field-effect transistor) or IGBT (insulated-gate bipolar transistor).

7. The converter system according to claim 1, the first series switch unit and/or the second series switch unit further comprising a precharging resistor and a semiconductor switch.

8. The converter system according to claim 1, the third series switch unit and/or fourth series switch unit comprising two switch elements arranged in a back-to-back position.

9. The converter system according to claim 1, the control unit comprising a separate digital signal processor for each of the first and second converter units or a single microcontroller to control them together.

10. The converter system according to claim 1, the control unit being configured to operate the third converter unit, even if the first converter unit and the second converter unit are turned off

11. The converter system according to claim 1, the first converter unit and the second converter unit being configured to transfer power from the low voltage system to the high voltage system.

12. The converter system according to claim 11, the first converter unit and the second converter unit comprising a dual active bridge unit or a phase shift unit.

13. A vehicle comprising the converter system according to claim 1, the vehicle being an electric vehicle.

14. The vehicle according to claim 13, the converter system being configured to operate a third converter unit in a key-off state.

15. A method for transferring power in a converter system, comprising the following steps: connecting a first converter unit and a second converter unit in parallel, connecting the first converter unit to a high voltage system via a first series switch unit, connecting the second converter unit to a high voltage system via a second series switch unit, connecting the first converter unit to the low voltage system via a third series switch unit, and connecting the second converter unit to the low voltage system via a fourth series switch unit, in case of a failure in the first converter unit, disconnecting the first series switch unit and the high voltage system, or in case of a failure in the second converter unit, disconnecting the second series switch unit and the high voltage system.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0045] Exemplary embodiments of the disclosure will be described in the following with reference to the following drawings.

[0046] FIG. 1 shows schematically and exemplarily an embodiment of a converter system for transferring power according to the disclosure.

[0047] FIG. 2 shows schematically and exemplarily an embodiment of a first converter unit according to the disclosure.

[0048] FIG. 3 shows schematically and exemplarily an embodiment of a circuit topology of the first and second converter unit according to the disclosure.

DETAILED DESCRIPTION

[0049] FIG. 1 show a converter system 1 for transferring power. The converter system 1 is configured to transfer power from a high voltage system 40 to a low voltage system 50 or from the low voltage system 50 to the high voltage system 40. The high voltage system 40 may have a voltage of 400V or 800V and the low voltage system 50 may have a voltage of 12V or 48V. The converter system 1 may be integrated in an electric vehicle to transfer power.

[0050] The converter system 1 includes a first converter unit 10, a second converter unit 20 and a control unit 60. The first converter unit 10 and the second converter unit 20 are connected in parallel. The first converter unit 10 and the second converter unit 20 may include an isolated a DC-DC converter. The first converter unit 10 is connected to the high voltage system 40 via a first series switch unit S1 and to the low voltage system 50 via a third series switch unit S3. The second converter unit 20 is connected to the high voltage system 40 via a second series switch unit S2 and to the low voltage system 50 via a fourth series switch unit S4.

[0051] The control unit 60 includes a separate digital signal processor for each of the first and second converter units 10, 20 or a single microcontroller to control them together. The control unit 60 is configured to disconnect the first series switch unit S1 and the high voltage system 40 in case of a failure in the first converter unit 10 or to disconnect the second series switch unit S2 and the high voltage system 40 in case of a failure in the second converter unit 20. Also, the control unit 60 is configured to disconnect the third series switch unit S3 and the low voltage system 50 in case of a failure in first converter unit 10 or to disconnect the fourth series switch unit S4 and the low voltage system 50 in case of a failure in the second converter unit 20. The failure may occur in each of the first and/or second converter unit 20, for example a hardware component failure, a software control failure or a combination of both.

[0052] If the control unit 60 receives any fault signal from the first converter unit 10, the control unit 60 may open the first series switch unit S1 to separate the first converter unit 10 from the second converter unit 20 and from the high voltage system 40. Meanwhile, the second series switch unit S2 may stay closed to maintain a connection with the high voltage system 40. In contrast, if the control unit 60 receives any fault signal from the second converter unit 20, the control unit 60 may open the second series switch unit S2 to separate the second converter unit 20 from the first converter unit 10 and from the high voltage system 40. Meanwhile, the first series switch unit S1 may stay closed to maintain the first converter unit 10 and the high voltage system 40.

[0053] Further, if the control unit 60 receives any fault signal from the first converter unit 10, the control unit 60 may open the third series switch unit S3 to separate the first converter unit 10 from the second converter unit 20 and from the low voltage system 50. Meanwhile, the second series switch unit S2 may stay closed to maintain a connection with the low voltage system 50. In contrast, if the control unit 60 receives any fault signal from the second converter unit 20, the control unit 60 may open the fourth series switch unit S4 to separate the second converter unit 20 from the first converter unit 10 and from the low voltage system 50. Meanwhile, the fourth series switch unit S4 may stay closed to maintain the first converter unit 10 and the high voltage system 50.

[0054] The converter system 1 further includes a low power isolated DC-DC converter as a third converter system 30. The low power isolated DC-DC converter may be a flyback converter configured to operate as a transformer. The low power isolated DC-DC converter 30 is connected to each of the first and second converter units 10, 20 in parallel and to each of the high voltage system 40 and low voltage system 50 directly. The low power isolated DC-DC converter is configured to supply power, particularly to low voltage loads such as opening a window or door, or starting a motor in case of a failure of the first and second converter units 10, 20 or in a key-off state of the vehicle. The control unit 60 is configured to operate the third converter unit 30, even if the first converter unit 10 and the second converter unit 20 are turned off

[0055] The first, second, third and/or fourth series switch unit S1, S2, S3, S4 includes a power semiconductor switch element 13 such as a MOSFET (metal oxide semiconductor field-effect transistor) or IGBT (insulated-gate bipolar transistor). The power semiconductor switch element 13 allows a fast response time of an opening and/or a closing of the switches.

[0056] As shown in FIG. 2, the first series switch unit S1 further includes a precharging resistor 14 and a semiconductor switch 15, which may be configured to control an opening and/or a closing of the first series switch unit S1. When turning on the switch element 13, the semiconductor switch 15 may be charged through the resistor 14, accordingly the resistor 14 may limit an inrush current to prevent a damage.

[0057] The third series switch unit S3 includes two switch elements 13 arranged in a back-to-back position, wherein the switch elements 13 includes a common source or common emitter configuration. Accordingly, the third series switch unit S3 may block a current flowing in a reverse direction and perform a reverse-voltage protection, in particular in a bi-directional power switch unit. The second series switch unit S2 includes the same switch configuration as the first series switch unit Si and the fourth series switch unit S4 the same switch configuration as the third series switch unit S3.

[0058] As shown in FIG. 3, the first converter unit 10 and the second converter unit 20 include a dual active bridge unit or a phase shift unit 51. The dual active bridge unit or the phase shift unit 51 may be a bi-directional DC-DC converter unit, which allows a bi-directional power transfer. The dual active bridge unit or the phase shift unit 51 may include a center-tapped transformer with two winding portions connected to secondary synchronous rectification switches or a secondary current doubler 52. Accordingly, a reliable transfer of power from the high voltage system 40 to the low voltage system 50 and from the low voltage system 50 to the high voltage system 40 may be realised.

[0059] It has to be noted that embodiments of the disclosure are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

[0060] While the disclosure has been illustrated and described in detail in the drawings and description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The disclosure is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed disclosure, from a study of the drawings, the disclosure, and the dependent claims.

[0061] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.