DE102019000352A1 - Power supply unit and method for providing a voltage - Google Patents

Abstract

The invention relates to a power supply unit (1) having a housing (2), and a first energy source (3), which provides a first voltage (U1), and a DC voltage converter (4), with which the first voltage (U1) in a second Voltage (U2) is transformable, and with a first voltage output (SA1) on the housing (2), on which the second voltage (U2) can be provided, by an undervoltage protection device (8) in the housing (2), which falls below a predefined threshold value can be activated by the second voltage (U2), and wherein a third voltage (U3) can be provided by a second voltage output (SA2) on the housing (2) on which an undervoltage protection device (8) is activated. Furthermore, the invention relates to a method for providing a second voltage (U2) of a power supply unit (1).

Description

The invention relates to a power supply unit having a housing and a first energy source, which provides a first voltage, and a DC-DC converter, with which the first voltage is transformable into a second voltage, and having a first voltage output to the housing, on which the second voltage can be provided is. Furthermore, the invention relates to a method for providing a second voltage of a power supply unit.

The DE 10 2015 108 372 A1 describes an electrical supply device for an electrical system of a vehicle, comprising at least one electrical power distributor, which is adapted to supply a plurality of electrical consumers with electrical energy, and at least one DC-DC converter, which is adapted to feed the at least one electric power distributor , Furthermore, the at least one electrical power distributor and the at least one DC-DC converter are spatially combined to form at least one single module. Furthermore, an electrical system of a vehicle is described with such an electrical supply device.

• - ein Batterie-System mit wenigstens zwei Batterieeinheiten, welches einen ersten Spannungsabgriff zur Ausgabe einer ersten elektrischen Ausgabespannung aufweist und einen zweiten Spannungsabgriff zur Ausgabe einer zweiten elektrischen Ausgabespannung aufweist;
• - eine Spannungskonvertierungseinheit mit einem Eingangs- und einem Ausgangsanschluss, welcher eine an einem Eingangsanschluss anliegende elektrische Eingangsspannung in einer an den Ausgangsanschluss bereitgestellte elektrische Ausgangsspannung umwandelt, die kleiner ist als die elektrische Eingangsspannung;
• - wobei der Eingangsanschluss mit dem ersten Spannungsabgriff betriebsmäßig elektrisch verbunden ist und der Ausgangsanschluss mit dem zweiten Spannungsabgriff betriebsmäßig elektrisch verbunden ist;
• - wobei der zweite Spannungsabgriff mittels eines Dioden-Elements mit den Batterieeinheiten elektrisch verbunden ist, derart, dass im Falle eines Abfallens der elektrischen Ausgangsspannung der Spannungskonvertierungseinheit unter einem vorbestimmten Schwellenwert den Ausgangsanschluss angeschlossene elektrische Verbraucher mittels der über das Dioden-Element bereitgestellten zweiten elektrischen Ausgangsspannung mit elektrischer Energie versorgbar sind.

The DE 10 2012 007 225 A1 describes a power supply system, in particular for a motor vehicle, comprising:

• - A battery system having at least two battery units, which has a first voltage tap for outputting a first electrical output voltage and a second voltage tap for outputting a second electrical output voltage;
• a voltage converting unit having an input and an output terminal which converts an input electrical voltage applied to an input terminal to an electrical output voltage provided to the output terminal smaller than the input electrical voltage;
• - wherein the input terminal is operatively connected to the first voltage tap and the output terminal is operatively connected to the second voltage tap in an operative manner;
• - Wherein the second voltage tap is electrically connected by means of a diode element to the battery units, such that in case of a drop in the electrical output voltage of the voltage converting unit below a predetermined threshold, the output terminal connected electrical consumers by means of the diode provided via the second electrical output voltage electrical energy can be supplied.

This results in a disadvantage that a battery supply device must be equipped with a separate separate additional battery in order to achieve a redundant power supply.

Object of the present invention is to provide a power supply unit and a method to provide in particular a more compact design of a vehicle electrical system and a more redundant power supply of the electrical system.

This object is achieved by a power supply unit and a method according to the independent patent claims. Meaningful developments emerge from the dependent claims.

One aspect of the invention relates to a power supply unit having a housing and a first power source providing a first voltage and a DC-DC converter in which the first voltage is transformable to a second voltage and having a first voltage output on the housing to which the second one Voltage is provided, wherein a second power source is formed in the housing, which provides the second voltage independently of the DC-DC converter. The power supply unit is formed, for example, with an undervoltage protection device which can be activated when the predefined threshold value falls below the second voltage. By placing the second energy source in the housing of the power supply unit, a smaller space requirement can be achieved in particular in a vehicle electrical system of a vehicle. Particularly advantageous is the compact design by the resulting lower mass of the vehicle.

For example, the housing may be formed of aluminum. By using aluminum can also be saved space or weight. In particular, the first energy source may be a battery or a battery pack. In particular, a voltage of 48 volts may be provided with the first power source. The DC-DC converter can be, for example, a DC / DC converter, which, for example, receives a voltage of 48 volts on the input side and converts these 48 volts into a voltage of 12 volts. This voltage of 12 volts is then applied to the output side of the DC-DC converter. The second energy source is also like the first power source in the housing of the power supply unit. In particular, the second energy source may be located on the output side of the DC-DC converter. In particular, with the second power source, the second voltage may be provided depending on the converted voltage of the DC-DC converter. In particular, the second power source provides a second voltage of 12 volts. As a result, in particular a redundant energy supply of the vehicle electrical system or the vehicle can be ensured. In particular, the second energy source is used to ensure that in the event of a failure of the DC-DC converter, the vehicle electrical system can continue to be supplied with a constant voltage of, in particular, 12 volts.

In particular, with the redundant provision of the second voltage, a high availability, in particular for vehicles with autonomous driving functions, can be created.

Furthermore, it can also be provided that any desired voltage can be converted into a further arbitrary voltage with the DC-DC converter.

In particular, the power supply unit can be associated with the undervoltage protection device in the same housing. For example, the undervoltage protection device may be arranged in front of the input side of the DC-DC converter or between the first power source and the DC-DC converter. With the undervoltage protection device can be achieved in particular in a case of damage, that in an insufficient power supply to the second voltage important vehicle components can be supplied with the third voltage or with a predefined voltage. The undervoltage protection device may in particular have a low-voltage detection switch and a switching element, which can be activated by the second voltage when the predefined threshold value is undershot and then the exemplary vehicle electrical system can be further supplied with the third voltage, in particular with 12 volts. For example, the threshold value can be predefined to a voltage value of 10 volts. In particular, an emergency power supply of the vehicle electrical system or of the vehicle can be provided with the undervoltage protection device. In particular, the third voltage may be provided at the second voltage output of the housing.

Preferably, it is provided that with a second energy source in the housing, which provides the second voltage independently of the DC-DC converter, and the DC-DC converter, the second voltage can be provided. By providing the second voltage with the second energy source and in particular simultaneously with the DC-DC converter, it is possible to ensure a high level of availability or a high energy supply of an energy consumer. In particular, a vehicle electrical system can be constantly supplied with the predetermined second voltage by the redundant provision of the second voltage. In particular, the second voltage is provided constantly and in each case separately from the second energy source and the DC-DC converter, so that in the event of failure of the second energy source or the DC-DC converter the second voltage can still be made available to the energy consumer or the energy on-board network.

It is preferably provided that the third voltage of the low-voltage protection device essentially corresponds to the second voltage. As a result, in the event of a failure of the second energy source and of the DC-DC converter, for example, the vehicle electrical system can continue to be supplied with the third voltage, which is the same, in particular essentially the same, of the second voltage. For example, the second and third voltages may each be 12V.

In an advantageous embodiment, it is provided that the second energy source is also designed as a lithium-ion accumulator. In particular, the second energy source may be formed as a lithium-ion battery or battery unit. By using lithium-ion batteries in particular a compact design can be achieved and thus in particular a compact design of the power supply unit can be ensured. In particular, lithium-ion batteries have a high energy density, which is needed in particular for the supply of a vehicle electrical system. Another advantage for the use of a lithium-ion battery is the comparatively long service life, which is particularly advantageous when used in motor vehicles. The lithium-ion battery in particular has no or a small memory effect, whereby the lithium-ion battery has only a very small drop in capacity over its lifetime.

It is preferably provided that a vehicle electrical system can be supplied with the second voltage with the second energy source and / or the DC-DC converter and / or the low-voltage protection device. In particular, with the second energy source and / or the DC converter of the power supply unit a vehicle electrical system of a vehicle, in particular an electrically operated vehicle are supplied with the second voltage. The vehicle electrical system can be, for example, a 12-volt 48-volt vehicle electrical system concept, which can be used in particular in electrically powered vehicles or vehicles. In particular, with the low-voltage protection device of the power supply unit, the vehicle electrical system of the vehicle can be monitored and, in the event of a damage, still supplied with the third voltage. For example, after activation of the low-voltage protection device, a driver warning may be sent to the vehicle occupants. For example, the driver warning can be done by means of visual or audible warning signals.

A further aspect of the invention relates to a method for providing a second voltage of a power supply unit which has a housing, wherein the second voltage is converted by a DC voltage converter from a first voltage, and a second voltage can be provided at a first voltage output at the housing. Preferably, the second voltage can be provided with a second energy source in the housing independently of the DC-DC converter, and / or if the second voltage falls below a predefined threshold, an under-voltage protection device in the housing can be activated, with the under-voltage protection device applying a third voltage to a second voltage output which is provided to the housing of the power supply unit. In particular, can be supplied with the second voltage of the power supply unit vehicle on-board network, which may be, for example, at the second voltage to a 12 volt voltage. The second voltage is converted in particular with a DC-DC converter or a DC / DC converter from a first voltage of a first energy source. The first voltage may be, for example, a 48 volt voltage or DC voltage. The power supply unit and the DC-DC converter and the first voltage source and the second voltage source may in particular be located in one and the same housing. As a result, in particular space can be saved and a compact design can be achieved. The second voltage is provided, in particular, redundantly to the vehicle power supply system, in particular with the second energy source, and likewise provided by the DC voltage converter to the vehicle electrical system. Due to the redundant provision of the second voltage, in particular, a vehicle electrical system can be supplied with greater safety and with increased availability with an electrical voltage. The energy supply unit may be formed, for example, with an undervoltage protection device, which ensures an emergency supply of an energy consumer or a vehicle electrical system when falling below the predefined threshold by the second voltage. For example, the threshold may be 10 volts.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

• 1 ein schematisches Aufführungsbeispiel einer Energieversorgungseinheit; und
• 2 einen schematischen Ablauf des erfindungsgemäßen Verfahrens.

In the accompanying drawings show:

• 1 a schematic performance example of a power supply unit; and
• 2 a schematic sequence of the method according to the invention.

The 1 shows preferably a schematic structure of a power supply unit 1 , The power supply unit 1 has in particular a housing 2 on, which may be formed for example of aluminum. Furthermore, the power supply unit comprises 1 a first source of energy 3 which may be, for example, a battery unit or an accumulator. With the first energy source 3 in particular, a first voltage U1 to be provided. For example, the first voltage U1 be a 48 volt DC. The power supply unit 1 in particular, a DC-DC converter 4 which may be, for example, a DC / DC converter. On the input side of the DC-DC converter 4 is about the first energy source 3 the first tension 1 the DC-DC converter 4 made available. The DC-DC converter 4 converts the first tension U1 in a second tension U2 around. In particular, the second voltage U2 12 Volt and this may be on the output side of the DC-DC converter 4 be tapped. The second tension U2 can, for example, at a first voltage output SA1 to be provided. For example, the second voltage U2 an energy consumer 5 to provide. At the energy consumer 5 For example, these may be vehicle components of a vehicle electrical system. The power supply unit 1 in particular, a second energy source 6 in the case 2 include, with which is the second tension U2 independent of the DC-DC converter 4 the energy consumer 5 can be provided. At the second energy source 6 in particular, it may be a 12 volt battery. In particular, the second energy source 6 be a lithium-ion battery or a lithium-ion battery. Likewise, the first energy source 3 also be a lithium-ion battery. By using lithium-ion batteries in particular the life of the energy sources can be increased and an increased energy density can be achieved. In particular, with the second energy source 6 and the DC-DC converter 4 the second tension U2 redundant to the energy consumer 5 to be provided. As a result, in particular in the case of a vehicle electrical system of an energy consumer 5 a high availability of the second voltage U2 be created. In particular, in case of failure of the second power source or the DC-DC converter 4 the energy consumer 5 continue with the second voltage U2 be supplied.

In particular, with the second energy source 6 and / or the DC-DC converter 4 a vehicle electrical system with the second voltage U2 be supplied.

For example, the first energy source 3 and the DC-DC converter 4 and the second energy source 6 and an undervoltage protection device 8th about a common mass 7 be grounded. For example, it may be in the vehicle mass 7 to act a vehicle mass of a motor vehicle.

The power supply unit 1 in particular, the undervoltage protection device 8th include, which are in the housing 2 is also located. With the undervoltage protection device 8th can be an emergency supply of the energy consumer 5 be ensured in case of damage. The undervoltage protection device 8th can be a low voltage detection switch 9 and a switching element 10 include. In the switching element 10 it may be, for example, a relay or a metal oxide semiconductor field effect transistor (MOSFET). Should be the second voltage U2 for example, drop below 10 V, the undervoltage detection switch 9 the switching element 10 enable it to be closed. The undervoltage protection device 8th can in particular by means of a voltage measuring unit, the second voltage U2 check.

In particular, with the undervoltage protection device 8th the energy consumer 5 in case of damage with a third tension U3 supply. The third tension U3 can be connected to a second voltage output SA2 the power supply unit 1 to be provided.

The 2 shows a schematic sequence for providing the second voltage U2 the power supply unit 1 ,

In a first step S1 especially the second voltage U2 with the DC-DC converter 4 from the first tension U1 being transformed. The second tension U2 especially the energy consumer 5 be made available, which may be, for example, a vehicle electrical system. In particular, the second voltage U2 with a second energy source 6 the power supply unit 1 independent of the DC-DC converter 4 to be provided. At the second energy source 6 it may be, for example, a lithium-ion battery. In particular, this can be a redundant provision of the second voltage U2 for the energy consumer 5 be guaranteed.

In a second step S2 especially the second voltage U2 at a first voltage output SA1 the power supply unit 1 to be provided.

In a third step S3 may be at a fall below a predefined threshold by the second voltage U2 the undervoltage protection device 8th the power supply unit 1 which are in the housing 2 is activated. For example, the threshold value can be defined at 10 volts, and if this threshold value is undershot, an emergency supply, in particular of the energy consumer, can be defined 5 be ensured. As a result, for example, a vehicle can be safely brought to a standstill in the event of a damage.

In a fourth step S4 can with the activated low voltage protection device 8th a third tension U3 at a second voltage output SA2 on the housing 2 the power supply unit 1 to be provided. The third tension U3 in particular corresponds substantially to the second voltage U2 ,

In an optional fifth step S5 can after triggering the undervoltage protection device 8th a repair, for example, the DC-DC converter 4 be performed. After the repair of the DC-DC converter 4 Re-balancing can be performed as a function. In this case, the undervoltage protection device 8th and the power supply 1 checked for active functionality with a zero current control.

LIST OF REFERENCE NUMBERS

1

Power supply unit

2

casing

3

first source of energy

4

DC converter

5

energy consumers

6

second energy source

7

Dimensions

8th

Undervoltage protection device

9

Low voltage detection circuit

10

switching element

U1

first tension

U2

second tension

U3

third tension

S1

first step

S2

second step

S3

Third step

S4

fourth step

S5

fifth step

SA1

first voltage output

SA2

second voltage output

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015108372 A1 [0002]
• DE 102012007225 A1 [0003]

Claims (6)

Power supply unit (1) having - a housing (2), and - a first power source (3), which provides a first voltage (U1), and - a DC-DC converter (4), with which the first voltage (U1) in a second voltage (U2) is transformable, and - with a first voltage output (SA1) on the housing (2) to which the second voltage (U2) is providable, characterized by - an undervoltage protection device (8) in the housing (2), which at Undershooting of a predefined threshold value by the second voltage (U2) can be activated, and - a second voltage output (SA2) on the housing (2) on which a third voltage (U3) can be provided when the low-voltage protection device (8) is activated. Power supply unit (1) after Claim 1 , characterized in that the second voltage (U2) can be provided with a second energy source (6) in the housing (2), which provides the second voltage (U2) independently of the DC-DC converter (4), and the DC-DC converter (4). Power supply unit (1) according to one of the preceding claims, characterized in that the third voltage (U3) of the low-voltage protection device (8) essentially corresponds to the second voltage (U2). Energy supply unit (1) according to one of Claims 2 to 3 , characterized in that the second energy source (6) is designed as a lithium-ion accumulator. Energy supply unit (1) according to one of Claims 2 to 4 , characterized in that with the second energy source (6) and / or the DC-DC converter (4) and / or the low-voltage protection device (8) a vehicle electrical system with the second voltage (U2) can be supplied. Method for providing a second voltage (U2) of a power supply unit (1) having a housing (2), - the second voltage (U2) being converted by a DC voltage converter (4) from a first voltage (U1) (S1), and - a second voltage (U2) at a first voltage output (SA1) to the housing (2) is provided (S2), characterized in that - in the case of falling below a predefined threshold by the second voltage (U2), an undervoltage protection device (8) in the housing (2) is activated (S3), wherein - with the undervoltage protection device (8), a third voltage (U3) at a second voltage output (SA2) on the housing (2) of the power supply unit (1) is provided (S4).

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