Energy monitoring system for a vehicle

Abstract

The present disclosure relates to an energy monitoring system for a vehicle, a vehicle comprising such an energy monitoring system and a method for manufacturing such an energy monitoring system.

The energy monitoring system comprises an on-board battery charging system, a traction voltage system and a control unit. The traction voltage system is connected to the on-board battery charging system and the control unit is configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold.

Claims

1. An energy monitoring system for a vehicle, the energy monitoring system comprising: an on-board battery charging system; a traction voltage system; and a control unit, the traction voltage system being connected to the on-board battery charging system; the control unit being configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold.

2. The energy monitoring system according to claim 1, further comprising: an energy storage system, the traction voltage system being arranged between the on-board battery charging system and the energy storage system.

3. The energy monitoring system according to claim 2, the control unit being configured to transfer energy from the traction voltage system to the on-board battery charging system only if the energy storage system is disconnected from the traction voltage system.

4. The energy monitoring system according to claim 1, the traction voltage system comprising at least one traction capacitor.

5. The energy monitoring system according to claim 1, the control unit being further configured to monitor the energy level of the traction capacitor.

6. The energy monitoring system according to claim 1, the on-board battery charging system comprising a bidirectional converter unit, through which energy stored in the traction voltage system being transferred to the on-board battery charging system.

7. The energy monitoring system according to claim 6, the bidirectional converter unit being a bidirectional DC/DC converter unit.

8. The energy monitoring system according to claim 1, the on-board battery charging system further comprising: at least one internal capacitor, the internal capacitor being configured to store the energy transferred from the traction voltage system.

9. The energy monitoring system according to claim 8, the internal capacitor being integrated in a power factor correction unit.

10. The energy monitoring system according to claim 9, the power factor correction unit being configured to utilize the energy stored in the internal capacitor prior to initiating an AC charging.

11. The energy monitoring system according to claim 1, the on-board battery charging system being always powered on.

12. A vehicle comprising: an energy monitoring system comprising: an on-board battery charging system; a traction voltage system; and a control unit, the traction voltage system being connected to the on-board battery charging system; the control unit being configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold, the vehicle being a battery electric vehicle or a hybrid electric vehicle.

13. The vehicle according to claim 12, a control unit being configured to start an energy transfer from a traction voltage system to an on-board battery charging system only if the vehicle being beyond a driving mode and a charging mode.

14. A method for manufacturing an energy monitoring system for a vehicle, comprising: providing a traction voltage system providing an on-board battery charging system; and connecting the on-board battery charging system with the traction voltage system, a control unit being configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold.

15. A method for operating an energy monitoring system in a vehicle, the method comprising: receiving information about an energy level of a traction voltage system; disconnecting the traction voltage system (30) from an energy storage system; determining if the energy level of the energy level of the traction voltage system exceeds a defined threshold; and transferring energy stored in the traction voltage system to an on-board battery charging system in case an energy level of the traction voltage system exceeds the defined threshold, and wherein an energy monitoring system comprising: an on-board battery charging system; a traction voltage system; and a control unit, the traction voltage system being connected to the on-board battery charging system; the control unit being configured to transfer energy stored in the traction voltage system to the on-board battery charging system in case an energy level of the traction voltage system exceeds a defined threshold

Description

BRIEF DESCRIPTION OF DRAWINGS

[0040] Exemplary embodiments will be described in the following with reference to the following drawings.

[0041] FIG. 1 shows schematically and exemplarily an embodiment of an energy monitoring system according to the present disclosure.

[0042] FIG. 2 shows schematically and exemplarily a flow chart diagram of a method for operating an energy monitoring system according to the present disclosure.

DESCRIPTION OF EMBODIMENTS

[0043] FIG. 1 shows an energy monitoring system 1 for a vehicle. The vehicle may be an electric vehicle such as a battery electric vehicle (BEV), a plug-in-hybrid electric vehicle (PHEV) and/or a hybrid electric vehicle (HEV).

[0044] The energy monitoring system 1 comprises an on-board battery charging system (OBC) 20, a traction voltage system (TVS) 30, an energy storage system 40 and a control unit 21. The traction voltage system 30 is connected to the on-board battery charging system 20 and also couplable with the energy storage system 40. The energy storage system 40 may be a high voltage battery pack, which may provide electrical energy to an electric machine for an electric vehicle propulsion and to auxiliary loads connected to the TVS 30.

[0045] The on-board battery charging system 20 may be configured to charge the energy storage system 40. The on-board battery charging system 20 comprises a power factor correction unit 22. The power factor correction unit 22 is connected to an external AC power supply 10 and configured to vary an output voltage in a predefined range. The power factor correction unit 22 comprises at least one internal capacitor 24, which is big enough to eliminate or reduce a voltage ripple caused by oscillations of the external AC power supply 10.

[0046] The on-board battery charging system 20 further comprises a bidirectional converter unit 23, preferably bidirectional DC/DC converter unit. The bidirectional DC/DC converter unit 23 may provide energy flow in buck and boost direction and a safe energy interface between the external AC energy source 10 and the energy storage system 40.

[0047] The traction voltage system 30 comprises at least one traction capacitor 31 configured to store electrical energy to balance fluctuating instantaneous power on rails of the TVS and to stabilize ripple current/voltage among different electrical components connected thereto. The traction voltage system 30 is connected to the energy storage system 40 during charging the energy storage system 40 or supplying power from the energy storage system 40. The traction capacitor 31 may contain electrical energy even though the traction voltage system 30 is operatively disconnected from the energy storage system 40, for instance after completion of charging the energy storage system or driving the vehicle.

[0048] The control unit 21 of the energy monitoring system 1 monitors an energy level of electrical energy stored in the traction capacitor 31, particularly if the traction voltage system 30 is disconnected from the energy storage system 40. The control unit 21 is integrated in the on-board battery charging system 20 and communicates with at least one of vehicle electronic control units and/or a measurement equipment inside the OBC to receive a signal whether the energy stored in the traction voltage system 30 exceeds a defined threshold or not. The energy level of the traction voltage system 30 may be indicated as a voltage value. The defined threshold may be a safe energy level of the traction voltage system 30.

[0049] In case the energy level of the traction capacitor 31 or the traction voltage system 30 exceeds the defined threshold, the control unit 21 prompt the on-board battery charging system 20 to transfer energy stored in the traction voltage system 30 to the OBC 20. Accordingly, even though the energy storage system 40 is in an inactive state, the bidirectional DC/DC converter unit 23, thus the on-board battery charging system 20 is always powered on.

[0050] The bidirectional DC/DC converter unit 23 enables energy flow either in buck or in boost direction such that excessive energy stored in the traction capacitor 31 may be transferred to the internal capacitor 24 of the power factor correction unit 22. Due to its big size, the internal capacitor 24 can store the transferred energy from the traction voltage system 30 without using any additional active or passive components such as switching circuit and/or resistor for dissipating the excessive energy in the TVS 30. The power factor correction unit 22 may utilize the energy stored in the internal capacitor 24 prior to initiating an AC charging.

[0051] FIG. 2 shows a flow chart diagram of a method for operating the energy monitoring system 1. The method comprises: [0052] S1: start; [0053] S2: receiving information about an energy level of the traction voltage system 30; [0054] S3: disconnecting a traction voltage system 30 from an energy storage system 40; [0055] S4: determining if the energy level of the energy level of the traction voltage system 30 exceeds a defined threshold; [0056] S5: transferring energy stored in the traction voltage system 30 to an on-board battery charging system 20, in case the energy level of the traction voltage system 30 exceeds the defined threshold; and [0057] S6: stop.
Preferably in the step S2, a status of the energy storage system 40 may be also measured and in the step S5, the traction capacitor 31 is discharged and the internal capacitor 24 is charged

[0058] 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.

[0059] 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.

[0060] 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.