DE102019125383A1 - Motor vehicle with two on-board electrical systems and one external electrical device connection - Google Patents

Abstract

The invention relates to a motor vehicle (10) having a high-voltage electrical system (11), a low-voltage electrical system (12) and an external device connection (37) for exchanging a supply voltage (34) with a non-vehicle external device unit (20). The invention provides that the third-party device connection (37) in the motor vehicle (10) is connected to at least one of the on-board networks (11, 12) via a connection circuit (19), the third-party device connection (37) in the connection circuit (19) being connected to one Intermediate circuit (47) is connected and the intermediate circuit (47) is connected to the respective vehicle electrical system (11, 12) by means of its own DC voltage converter (38, 39), the respective DC voltage converter (38, 39) on the one hand for a DC low voltage which is less than 60 volts, and on the other hand is set up for the on-board network voltage of the respective on-board network (11, 12), and a control circuit (40) is set up to measure an electrical current (35, 36) that the respective DC voltage converter (38, 39) exchanges with the respective vehicle electrical system (11, 12), to keep the amount below a predetermined threshold value.

Description

The invention relates to a motor vehicle which has a high-voltage on-board network and a low-voltage on-board network, both of which are connected to one another via a DC voltage converter. In addition, an external device connection is provided in the motor vehicle, to which an external electrical device or an external electrical device unit, for example another motor vehicle, can be connected in order to receive a supply voltage from outside the vehicle, e.g. for a jump-start aid, or to output a supply voltage from the vehicle to the external device unit.

In a motor vehicle, however, a supply voltage can be required not only for a jump-starting aid, but for many other reasons. In a motor vehicle with an electric drive or a hybrid vehicle, a supply voltage can also be used, for example, to charge the vehicle's own energy storage device, that is to say for example the high-voltage battery. For example, in a similar way to a reserve canister, a reserve battery can be connected to the motor vehicle as an external device unit. Additionally or alternatively, you may be interested in connecting a photovoltaic system in a house or on the roof of the motor vehicle as a third-party device unit to the motor vehicle for charging a battery of the motor vehicle. Another possible third-party device unit can also be a power supply unit or a charger for providing what is known as a low voltage (electrical voltage that is less than 60 volts in terms of magnitude) in order to enable a battery of the motor vehicle to be charged with what is known as protective low voltage.

Depending on the third-party device, the supply voltage can have a different voltage level.

The coupling of a vehicle battery both with a charger, which generates a DC charging voltage from an alternating voltage of a public power grid, and with a photovoltaic system is, for example, from the EP 3 159 998 A1 known. In order to protect the individual components from compensating currents that are too high due to voltage differences, this solution requires several voltage converters, which makes the implementation of this solution complex in terms of circuitry.

To protect a vehicle battery from overcurrent, the DE 10 2017 201 241 A1 known to couple a high-voltage battery of the motor vehicle with the electrical system of the motor vehicle via a DC voltage converter. By providing a further DC voltage converter, it can be achieved that the battery can be coupled efficiently by operating either a bidirectional DC voltage converter or a unidirectional DC voltage converter. An additional connection of a third-party device is not possible with this arrangement.

From the DE 10 2018 107 044 A1 It is known that in a motor vehicle a high-voltage on-board network and a low-voltage on-board network can be interconnected via an internal DC voltage converter, so that electrical energy from the high-voltage on-board network can be made available in the low-voltage on-board network. The DC / DC converter thus acts as a low-voltage source in the low-voltage vehicle electrical system. In order to connect a consumer external to the vehicle to the motor vehicle, a supply voltage for the consumer can be provided from a high-voltage electrical system of the motor vehicle by means of a DC voltage converter. The feeding of electrical energy from different external device units into the high-voltage on-board network is not described.

The transfer of a supply voltage to a third-party device unit, e.g. an electric scooter or an electric bicycle, can also be of interest.

The invention is based on the object of enabling electrical energy to be exchanged with different external device units in a motor vehicle with little circuit complexity.

The object is achieved by the subjects of the independent claims. Advantageous embodiments of the invention are described by the dependent claims, the following description and the figure.

A motor vehicle is provided by the invention. The invention is based on the assumption that there are two vehicle electrical systems in the motor vehicle, namely a first electrical system, which is a high-voltage electrical system, and a second electrical system, which is a low-voltage electrical system. A high-voltage source (or multiple high-voltage sources) of the vehicle's own is provided in the high-voltage electrical system, each of which is set up to provide a DC high-voltage voltage (DC - direct current) of more than 60 volts as the electrical system voltage in the high-voltage electrical system. A high-voltage battery (traction battery) and / or a fuel cell, for example, can be provided as the respective high-voltage source. The vehicle's own low-voltage source or several low-voltage sources are provided in the low-voltage electrical system, each of which is set up for this purpose is to provide a protective extra-low voltage or DC low voltage of 60 volts or less than 60 volts as the vehicle electrical system voltage in the low-voltage vehicle electrical system. An internal DC voltage converter is provided as such a low-voltage source, which connects the low-voltage on-board network with the high-voltage on-board network. The term "internal" is only given for better differentiation and means that it is a vehicle-internal connection between the high-voltage on-board network and the low-voltage on-board network. A battery (that is to say an electrochemical accumulator), for example, can also be provided as a further possible low-voltage source.

In order to be able to interconnect the motor vehicle from outside or externally with electrical energy, a third-party device connection is provided which is set up to receive and / or output a supply voltage. The external device connection is thus set up to exchange the supply voltage with an electrical external device unit that is not part of the vehicle, which means that the supply voltage can be received from and / or output to the external device unit. Such a third-party device connection can, for example, have at least one electrical connection contact. For example, it can be a metal bolt to which a positive pole of the external device unit can be connected. Furthermore, the external device connection can also provide a connection between the vehicle ground and a negative pole of the external device unit. The external device connection thus has at least one connection contact that is accessible from the outside via an access device. “Access device” here means mechanical or spatial access, which can be provided, for example, via a flap or an engine hood of the motor vehicle or a passage opening. A user must therefore open the access device, such as the flap or the engine hood, in order to access the external device connection from the outside. However, the access device can also simply be a through opening through which the external device connection can be reached from the outside.

In order to be able to alternately or at the same time connect different third-party device units that are designed for different supply voltages to such a motor vehicle, the invention provides that the third-party device connection, i.e. for example the at least one connection contact of the third-party device connection, in the motor vehicle via a connection circuit with at least one of the two Vehicle electrical system is connected. Here, the external device connection is connected to an intermediate circuit (DC intermediate circuit) of the connection circuit and this intermediate circuit is connected to the respective on-board network to which the connection circuit is connected by means of a respective or its own DC voltage converter. An electrical connection leads from the intermediate circuit via a respective DC voltage converter into at least one of the vehicle electrical systems. The respective DC voltage converter is designed to exchange the respective vehicle electrical system voltage of the respective vehicle electrical system. Thus, by connecting a third-party device unit to the third-party device connection, electrical energy can be transferred into the intermediate circuit of the connection circuit and transferred from there into at least one of the vehicle electrical systems by means of a respective DC voltage converter. Conversely, electrical energy from one of the vehicle electrical systems or from both vehicle electrical systems can be output via the external device connection.

A control circuit is set up to detect or measure a current intensity of an electrical current that the respective DC voltage converter exchanges with the respective vehicle electrical system and to keep the current intensity below a predetermined threshold value by controlling the respective DC voltage converter.

The respective DC voltage converter is set up to receive a DC low-voltage voltage that is less than 60 volts from the intermediate circuit and thus also via the external device connection or to output such a DC low-voltage voltage to the intermediate circuit and thus via the external device connection. In other words, a low-voltage voltage can be fed into the connection circuit via the third-party device connection so that it is available there in the intermediate circuit, and / or, conversely, the low-voltage voltage can be generated in the intermediate circuit and output via the third-party device connection. The respective DC voltage converter can then be used to convert between the DC low-voltage voltage of the intermediate circuit and the respective on-board network voltage of one or both of the on-board networks and thus exchange electrical energy with the respective on-board network, i.e. transfer it into or out of it.

The invention has the advantage that any low-voltage voltage (from, for example, 5 volts to 60 volts) can be fed in by an external device unit at the external device connection and can supply this on-board network with the required on-board voltage for at least one of the vehicle electrical systems by means of its connection circuit. In this way, a supply voltage in the low-voltage range can be fed into the motor vehicle universally via the external device connection and used for this in the motor vehicle to supply at least one of the vehicle electrical systems. Conversely, electrical energy can be output from at least one of the vehicle electrical systems via the external device connection to an external device unit.

Since the current intensity is monitored by the control circuit and limited to the threshold value by means of the respective DC voltage converter, there cannot be an equalizing current greater than the threshold value if there is a difference in the voltage level between the supply voltage and the voltage level of the vehicle electrical system voltage of the respective vehicle electrical system. In particular in the case of a DC / DC converter that couples the intermediate circuit with the low-voltage on-board network, in contrast to the jump-start connections known so far from the prior art (for example on the 12-volt battery of a motor vehicle), a compensating current for different states of charge (SOC - state of charge) between the low-voltage batteries of two motor vehicles is avoided.

The invention also encompasses embodiments which result in additional advantages.

In one embodiment, the connection circuit has only one DC voltage converter and this is connected to the high-voltage on-board electrical system. In this case, the control circuit is designed to transfer electrical energy between the external device connection on the one hand and the low-voltage on-board network on the other hand by operating the said internal DC voltage converter between the high-voltage on-board network and the low-voltage on-board network. This means that electrical energy can be transmitted from the supply connection via the high-voltage on-board network to the low-voltage on-board network. In this way, even in the event that only one DC voltage converter is provided for supplying the high-voltage on-board network, it is nevertheless possible to supply both on-board networks with electrical energy from an external device unit with just one DC voltage converter.

In one embodiment, the internal DC voltage converter is set up to transmit bidirectionally between the high-voltage on-board network and the low-voltage on-board network. The control circuit is set up to transfer electrical energy from the low-voltage on-board network to the high-voltage on-board network. This results in at least the following two advantageous applications. On the one hand, a low-voltage voltage can be received via the external device connection and fed into the low-voltage vehicle electrical system and from there further transmitted to the high-voltage vehicle electrical system via the bidirectional internal DC voltage converter. This enables so-called low-voltage charging of the vehicle's own high-voltage source via the low-voltage on-board network. Another advantageous area of application is the aforementioned transmission in the event that only one DC voltage converter is available to the high-voltage on-board network. Electrical energy can then be transferred from the low-voltage on-board network via the bidirectional DC voltage converter to the high-voltage on-board network and from there to the external device connection, so that electrical energy can also be transmitted from the low-voltage on-board network to the external device connection.

It can also be provided that only a single DC voltage converter is provided in the connection circuit and this is connected to the low-voltage on-board network.

Said control circuit can be implemented, for example, on the basis of at least one microprocessor and / or at least one microcontroller. The control circuit can be implemented as a single control device or as a network of several control devices.

In one embodiment, said external device connection for connecting a non-vehicle external device unit on the one hand and additionally at least one in-vehicle electrical connection interface for an in-vehicle electrical additional supply source are jointly connected via said intermediate circuit to the at least one DC-DC converter of the connection circuit. An additional supply source of the motor vehicle itself can therefore also be connected internally to at least one of the vehicle electrical systems via the same intermediate circuit. Such an additional supply source can be, for example, a photovoltaic system or a mobile additional battery or a low-voltage charger. The at least one vehicle-internal electrical connection interface results in several connection options for the intermediate circuit for providing a low-voltage voltage in the motor vehicle, which can then be fed directly into the vehicle electrical system by means of the at least one DC voltage converter of the connection circuit (or indirectly via the internal DC voltage converter if only one DC voltage converter is used) . The circuitry complexity for connecting an external device unit and at least one additional supply source internal to the vehicle is thus limited to providing the connection circuit.

If, however, several low-voltage supply sources (external device unit and at least one additional supply source) are connected to the intermediate circuit, one may be interested in resolving conflicts that arise when the different supply sources are different Provide voltage level. Otherwise a compensating current can flow.

One embodiment provides that an arbiter circuit (arbiter circuit) is provided, which is set up to connect the external device connection and the at least one connection interface to the intermediate circuit only in the event that a voltage difference between the supply voltage and one via the respective connection interface received electrical voltage is smaller than a predetermined threshold value in terms of amount. In other words, the arbiter circuit first checks which electrical voltage is to be expected from the external device unit (supply voltage) and the at least one connection interface. This procedure is particularly suitable for a positive flow of energy into the motor vehicle. When discharging (negative energy flow from the motor vehicle), communication with the energy sink (energy-consuming external device unit) can be established, e.g. for a voltage and / or current specification. In general, there are both applications with and without a need for communication. Voltage and / or current values can be achieved, for example, by measuring the respective voltage or voltage level or the respective voltage level or by querying the planned voltage level via a communication device with a respective control of the external device unit and the at least one additional supply source. In addition or as an alternative to this, the user can select an operating mode in the motor vehicle, for example in the case of a 12V battery charger (e.g. in a car workshop or for home use), the voltage of the lead-acid battery can be detected in an operating mode and the battery can be supplied. That would be an example for the "Charge 12V lead-acid battery" mode. If the voltage levels are then known, they can be compared and it can be checked whether the difference in the voltages is smaller than a predetermined threshold value in terms of magnitude. The threshold value can, for example, be in a range from 0.2 volts to 4 volts. Since these are DC voltages, it can be assumed that the voltages are not polarized. Two supply sources, the external device unit and at least one additional supply source from the motor vehicle itself can now feed in at the same time in order to supply at least one of the vehicle electrical systems with electrical energy via the respective DC voltage converter of the connection circuit. As an alternative to this, it can be provided that the arbiter circuit only grants exclusive access to the intermediate circuit, that is to say only one supply source is connected to the intermediate circuit at a time.

In order to implement the arbiter circuit in terms of circuitry, one embodiment provides that the arbiter circuit connects the external device connection and each connection interface to the intermediate circuit via its own switching element. Such a switching element can be, for example, a relay or a transistor. By means of such a switching element, simultaneous contacting of different supply sources can be excluded.

Additionally or alternatively, the arbiter circuit is set up in one embodiment to signal via a communication device to an external device unit connected to the external device connection and / or an additional supply source connected to a connection interface whether a voltage output is permitted. If the respective supply source (external device unit, additional supply source) is a so-called “intelligent” supply source, ie a supply source with its own control circuit or its own control device, the voltage output can also be set via a communication device. This can save the provision of a switching element for such a supply source. The same applies to an “intelligent” consumer. A communication device can be implemented in a wired or wireless manner by radio. Corresponding communication devices can be found in the state of the art.

In one embodiment, both DC voltage converters are provided in the connection circuit, i.e. both a DC voltage converter for the high-voltage electrical system and a DC voltage converter for the low-voltage electrical system, and the external device connection is electrically connected to both DC voltage converters via the intermediate circuit. This creates the possibility of feeding electrical energy into the vehicle electrical system via two electrical channels.

In one embodiment, the respective DC voltage converter of the connection circuit is designed as a bidirectional converter and the control circuit is configured to use the vehicle electrical system voltage of the respective vehicle electrical system to which the DC voltage converter is connected to generate an adjustable or predeterminable, regulated charging voltage for a specified external device, its own having electrical energy storage to provide. The motor vehicle can thus be used as a charging station for the external device. In other words, such a device is an external device unit that acts as an electrical consumer or as an electrical sink. Such a device can, for example, be an electric small powered vehicle, such as an electric scooter or an electric bicycle. However, the external device can also be, for example, another motor vehicle which, for example, requires electrical energy for starting assistance. By regulating the energy flow or the current intensity through the respective DC / DC converter, there is a difference in electrical voltage between the external device and the external device connection, preventing an equalizing current whose current intensity is greater than the aforementioned threshold value.

The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger vehicle or truck, or as a passenger bus or motorcycle.

The invention also includes the combinations of the features of the described embodiments.

• Fig. eine schematische Darstellung einer Ausführungsform des erfindungsgemäßen Kraftfahrzeugs und mehrerer Fremdgeräteeinheiten.

Exemplary embodiments of the invention are described below. The only figure shows this

• FIG. 1 shows a schematic representation of an embodiment of the motor vehicle according to the invention and several external device units.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention which are to be considered independently of one another and which also further develop the invention in each case independently of one another. Therefore, the disclosure is also intended to include combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

In the figure, functionally identical elements are provided with the same reference symbols.

The figure shows a motor vehicle 10 , which can be a motor vehicle, in particular a passenger car or truck. In the motor vehicle 10 can use a first on-board network 11 and a second electrical system 12th be provided, to each of which one or more electrical consumers can be connected, but which are not shown in the figure for the sake of clarity. The first electrical system 11 can be a high-voltage electrical system 13th be in which a vehicle's own high voltage source 14th , in particular a high-voltage battery or traction battery, can provide a vehicle electrical system voltage as direct voltage or DC high-voltage voltage. The second electrical system 12th can be a low-voltage electrical system 15th be in which at least a low voltage source 16 or more than one low voltage source 16 , 17th a low-voltage direct voltage or DC low-voltage voltage can be provided. The DC low-voltage voltage can be 12 volts, for example. In the figure it is shown how as a low voltage source 16 a DC / DC converter 18th can be provided which is unidirectional from the high-voltage electrical system 13th into the low-voltage electrical system 15th or can transmit electrical energy bidirectionally in both transmission directions. Another possible low voltage source 17th can be implemented, for example, by a low-voltage battery, for example a 12-volt battery (12 V-Bat).

In the motor vehicle 10 it can be provided that not only within the vehicle electrical system 11 , 12th electrical consumers and / or electrical power sources are connected or supplied, but that also from outside the vehicle electrical system 11 , 12th electrical energy into the high voltage source 14th and / or in the low voltage source 17th can be fed in and / or from the high voltage source 14th and / or the low voltage source 17th electrical energy can be taken to outside of the vehicle electrical system 11 , 12th to be used. This is in the motor vehicle 10 a connection circuit 19th provided, via which an exchange of electrical energy between at least one of the vehicle electrical systems 11 , 12th on the one hand and at least one external device unit external to the vehicle 20th can be provided or enabled. In addition, additional supply sources that are not part of the vehicle electrical system can also be used in the motor vehicle 21 also via the connection circuit 19th with at least one of the electrical systems 11 , 12th get connected.

From the foreign device units 20th can be a vehicle, for example 22nd be, for example an automobile or passenger car or truck, from which by means of a low-voltage battery 23 electrical energy can be provided or its low-voltage battery 23 should be charged.

A power supply unit external to the vehicle 24 for the transmission of electrical energy between an electrical alternating current network 25th and the connection circuit 19th , for which a rectifier AC / DC converter can be provided, which is also bidirectional and thus also as an inverter 26th can be operated, another third-party device unit 20th can be an electric vehicle 27 (Electric vehicle) being the electric vehicle 27 its own high-voltage battery 28 may have, with the electrical energy via a DC voltage converter 29 with the connection circuit 19th can be exchanged.

Another possible third-party device unit 20th can be a stationary electrical energy storage device external to the vehicle 30th be, for example, an electrical storage unit 31 , for example, an electrical accumulator or an external battery (Ext. Bat.), which can have a converter 32 for example with a household 33 can be connected. The electrical storage unit 31 can also use electrical energy with the connection circuit 19th change.

The possible different foreign device units 20th can have different voltage levels 34 for a respective DC voltage or DC voltage. Still, the connection circuit is 19th able to handle these different voltage levels of the possible supply voltages 34 to receive and in the respective suitable vehicle electrical system voltage of the vehicle electrical system 11 , 12th to convert and here also an amperage of an electric current 35 , 36 to control the between the one hand the connection circuit 19th and on the other hand one of the vehicle electrical systems 11 , 12th , can flow.

To receive the supply voltage from outside the vehicle 34 can through the connection circuit 19th a third-party device connection 37 be provided, for example, as an electrical connection contact 37 ' , for example, can be designed as an electrical connection bolt or as a plug socket or as a charging cable. The third-party device connection 37 can, for example, provide copper or aluminum or an alloy as the material for the electrical line.

The third-party device connection 37 can be used with one of the vehicle electrical systems 11 , 12th via a respective DC voltage converter 38 , 39 be interconnected. A control circuit 40 can use the respective DC / DC converter 38 , 39 control to the effect that this is for the respective electrical system 11 , 12th to which it is connected, the current strength of the electrical current fed in or withdrawn 35 , 36 can regulate to a predetermined setpoint. The control circuit 40 can for this purpose detect the current strength of the current by means of a measuring circuit known per se.

To the additional sources of supply 21 with the electrical systems 11 , 12th To be able to connect electrically, can in the motor vehicle 10 also a connection interface 41 for at least one additional supply interface or connection interface 41 be provided. Possible sources of supplementary care 21 can be the following: a solar panel or photovoltaic module 42 (PV), a portable or mobile battery 43 (mob. Bat), a low voltage charger 44 (LVC - low voltage charger).

Any of these supplementary care sources 21 each can have a different electrical voltage 45 provide, which in particular also differ from a supply level currently available at the external device connection 24 can distinguish.

To provide an equalizing current between the connection interface 41 and the external device connection 37 can prevent an arbiter circuit 46 be provided in the event of too great a difference in voltage 34 , 45 only one electrical source, i.e. the one currently connected to the external device connection 37 connected third-party device 20th or an additional source of care 21 at the connection interface 41 with the at least one DC voltage converter 38 , 39 connects. To the arbiter circuit 46 with the at least one DC voltage converter 38 , 39 to connect can in the connection circuit 19th an intermediate circuit 47 be provided for the transmission of direct voltage or DC voltage in the low-voltage range (less than 60 V).

The figure shows the arbiter circuit 46 with switching elements 48 , through each of which there is a galvanic separation between the connection interface 41 and the intermediate circuit 47 on the one hand and the external device connection 37 and the intermediate circuit 47 on the other hand, by opening the respective switching element 48 can be effected. the switching elements can be controlled by an appropriate control 49 switched, which also the received voltages 34 , 45 in relation to a threshold 50 the voltage difference between the voltages 34 , 45 can evaluate and if the difference is less than the threshold 50 can even be a third-party device unit 20th as well as an additional source of care 21 at the same time electrical energy in the intermediate circuit 47 feed in or take from it. There can also be a transmission from a supplementary supply source 21 via the intermediate circuit 47 towards the external device connection 37 and / or from the external device connection 37 towards the connection interface 41 via the arbiter circuit 46 done by both switching elements 48 be switched electrically conductive. A switching element 48 can for example be implemented on the basis of a relay and / or at least one transistor, in particular a field effect transistor.

• - zum Fremdstart 12V,
• - zum Anbinden von Zusatzspeichern ans Fahrzeug,
• - zur Anbindung von Fahrzeug-PV-Anlagen
• - für Umladevorgänge zwischen E-Fahrzeugen,
• - zur HV-Versorgung durch externe NV-Netzteile (NV - Niedervolt),
• - zur Anbindung von externen Speichern (z.B. Heimspeicher)
• - zur Anbindung Low-Voltage-Charging (LVC),
• - zur Anbindung von Elektrokleinstfahrzeugen (z.B. Elektrofahrrad).

It thus arises with the connection circuit 19th a universal vehicle DC energy interface that can provide for a restriction to protective extra-low voltage. It is suitable

• - for jump start 12V,
• - to connect additional storage to the vehicle,
• - for connecting vehicle PV systems
• - for reloading between e-vehicles,
• - for HV supply through external LV power supplies (LV - low voltage),
• - for connecting external storage (e.g. home storage)
• - for connecting low-voltage charging (LVC),
• - for connecting small electric vehicles (e.g. electric bicycles).

In the prior art, only independent individual solutions that cannot be combined are available for this purpose.

Jump start 12V: Conventionally powered vehicles are now recharged with an empty 12V battery using jumper cables or 12V workshop chargers. Even with electrified and electric vehicles, a discharge of the 12V on-board network leads to the need for a jump start, as with conventional electric vehicles. Alternatively, additional assemblies are installed in third-party vehicles, e.g. to use the onboard charger to also be able to charge 12V. For this purpose, the motor vehicle is discharged and the electric bicycle battery or the scooter battery is charged.

Flexible additional storage in the vehicle: In analogy to the reserve canister, an additional storage can be installed in the vehicle. Due to the different voltage levels compared to the vehicle battery, it has so far not been possible to introduce this battery into the vehicle without a converter system.

For connecting vehicle PV systems: Various manufacturers have already reported about PV systems on e-vehicles. Due to the effort involved in storing the PV energy in 12V or in the HV battery in the vehicle, implementation is costly (due to a converter system that is specifically required for this).

Transfer processes between vehicles: As of today, no electric vehicle without an infrastructure converter (e.g. so-called DC wallbox with AC / DC converter) can map a transfer process of the HV battery between 2 vehicles. As a preliminary development, it is known that work is being carried out on bidirectional onboard chargers that would allow the exchange of energy, but additional external safety electronics are also required for this.

HV supply through external LV power supply units: As of today, electric vehicles are only supplied with HV-DC or HV-AC charging technologies (and wireless charging). It does not work with a simple voltage source (possibly low voltage). Charging does not work even without a specific country charging standard.

Connection of external storage (e.g. home storage): Energy from external storage can only be loaded into the vehicle using charging electronics. This requires external and internal converters between external storage and vehicle storage.

Connection of low-voltage charging (LVC): In the series pre-development of the LVC, a dedicated converter is being developed for this system. Either you can use this converter for all other applications (additional switches required) or you can use a generic converter for LVC.

Connection of small electric vehicles: No charging in the vehicle or on the vehicle possible.

• Aufgrund der Zugänglichkeit und der verschiedenen, eingesetzten 12V-Batterien (z.B. Blei oder Lithium) bzw. Restriktionen im 12V-Bordnetz wird ein Fremdstart zunehmend schwierig umzusetzen bzw. ist in manchen Baureihen von Fremdfahrzeugen gar nicht mehr möglich.

The following technical problems exist in the prior art:

• Due to the accessibility and the various 12V batteries used (e.g. lead or lithium) or restrictions in the 12V on-board network, jump starting is becoming increasingly difficult or is no longer possible in some series of third-party vehicles.

Flexible additional storage in the vehicle: Without additional storage, there is no possibility of increasing the maximum range or plugging in reserve energy.

To connect vehicle PV systems: Specific DCDC converters are required to connect PV systems (only for this one application).

Reloading processes between vehicles: E-vehicles are always dependent on the charging infrastructure without being able to reload the vehicle.

HV supply through external LV power supply units: A flexible supply from various workshop power supply units is not possible today and would only be feasible with an additional function in the 12V / HV converter and there only if this allows 12V-> HV conversion.

To connect external storage (e.g. home storage): high power electronics effort in the charging infrastructure.

LVC D / DC converter cost makes the LVC system expensive. Only if several applications use this converter could the costs be passed on.

Small electric vehicles: It is possible to take them with you in the car for the “last mile”. But nowadays an electric scooter always has to be charged from a socket.

A motor vehicle with the universal external device connection described and the connection circuit described can produce the following advantageous effects.

By introducing a universal DC energy interface (connection circuit 19th ) with a flexible voltage range (the exact range can be determined by a specialist in the design) into the vehicle, new applications can be coupled to the existing on-board power supply.

As of today, many applications fail because there is no connection option to the HV battery or the 12V / 48V storage. A DCDC converter and a connection point / contact could make this interface possible. Since there is no other DCDC converter available in the on-board network apart from the HV-12V and HV-48V converter, many applications fail and cannot be used. With at least one universal additional converter 38 , 39 and fixed connection points, these applications could be implemented multifunctionally in the vehicle. The connection point for the vehicle for external component connection (third-party device connection 37 ) can, for example, be designed as a connection bolt in the safety extra-low voltage area (compare jumper cables). In the case of higher voltage levels, the HV-safe connection must be carried out.

1. 1. Fremdstart 12V
2. 2. Anbinden von Zusatzspeichern ans Fahrzeug,
3. 3. Anbindung von Fahrzeug-PV-Anlagen
4. 4. Umladevorgänge zw. E-Fahrzeugen,
5. 5. HV-Versorgung durch externe NV-Netzteile,
6. 6. Anbindung von externen Speichern (z.B. Heimspeicher)
7. 7. Anbindung LVC-Charging
8. 8. Anbindung Elektrokleinstfahrzeugen (E-Scooter)

The following applications could be implemented or the following components external and internal to the vehicle could be connected to the electrified or purely electric vehicle as an example.

1. 1. Jump start 12V
2. 2. Connection of additional storage devices to the vehicle,
3. 3. Connection of vehicle PV systems
4. 4. Reloading processes between e-vehicles,
5. 5. HV supply through external LV power supply units,
6. 6. Connection of external storage (e.g. home storage)
7. 7. Connection to LVC charging
8. 8. Connection of small electric vehicles (e-scooters)

• Ein einziger Wandler mit einem breiten Spektrum an Universalanwendungen:
  • - Realisierung neuer, innovativer Fahrzeugfunktionen,
  • - Kostenvorteil durch Mehrfachnutzung der notwendigen Bauteile,
  • - Variabilität: elektrische Komponenten mit flexiblem Spannungsbereich anbindbar,
  • - Beibehaltung bestehender Funktionalitäten aus dem konventionellen Fahrzeug (12V Fremdstart),
  • - Einfache Handhabung und reduzierte Systemkomplexität des E-Fahrzeugs mit seiner Energieinfrastruktur.

The advantages are, for example, as follows:

• A single converter with a wide range of general-purpose applications:
  • - Realization of new, innovative vehicle functions,
  • - Cost advantage through multiple use of the necessary components,
  • - Variability: electrical components with flexible voltage range can be connected,
  • - Retention of existing functionalities from the conventional vehicle (12V jump start),
  • - Easy handling and reduced system complexity of the e-vehicle with its energy infrastructure.

1. 1. Fremdstart 12V-Stromlimitierter bei einem Umladevorgang,
2. 2. Anbinden von Zusatzspeichern ans Fahrzeug,
3. 3. Anbindung von Fahrzeug-PV-Anlagen,
4. 4. Umladevorgänge zwischen E-Fahrzeugen,
5. 5. HV-Versorgung durch externe NV-Netzteile,
6. 6. Anbindung von externen Speichern (z.B. Heimspeicher),
7. 7. Anbindung LVC-Charging,
8. 8. Laden Elektroscooter im oder am Elektroauto, insbesondere ohne weiteres Netzteil.

Advantages in the individual applications:

1. 1. External start of 12V current limited during a recharging process,
2. 2. Connection of additional storage devices to the vehicle,
3. 3. Connection of vehicle PV systems,
4. 4. Reloading processes between e-vehicles,
5. 5. HV supply through external LV power supply units,
6. 6. Connection of external storage (e.g. home storage),
7. 7. Connection to LVC charging,
8. 8. Charging the electric scooter in or on the electric car, especially without an additional power supply unit.

For this purpose, an on-board DC / DC converter is preferred in the vehicle 38 ) with a voltage range to be specified, which is connected to at least one vehicle-internal energy storage device. In the case of an electric vehicle, ideally on the HV storage system (high-voltage battery 14th ) in order to be able to transfer a lot of energy. In the case of e-vehicles and other electrified vehicles, the additional connection of 12V or 48V batteries would be helpful (DC voltage converter 39 ) in order to be able to provide further applications. The electrical power interface to the new external or internal electrical components should be able to cover as wide a voltage range as possible, with different requirements being placed on the contact point, the cable routing and safety from a voltage threshold greater than 60V (protective low voltage threshold). The technically simplest and most pragmatic implementation (all applications mentioned would work with it) would be to use the voltage range of 0-60V.

Depending on the application, communication with the connected new electrical components or customer input is required Adjustments to the current will be required. The feasibility of such a converter system (connection circuit 19th ) is classified as technically feasible in the short term.

Overall, the examples show how the invention can provide a universal vehicle DC energy interface, in particular for protective extra-low voltage (amount less than 60 V).

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• EP 3159998 A1 [0004]
• DE 102017201241 A1 [0005]
• DE 102018107044 A1 [0006]

Claims (9)

Motor vehicle (10), comprising: - a first on-board network (11), which is an electrical high-voltage on-board network (13), in which at least one vehicle-own high-voltage source (14) is provided, which is set up to supply a on-board network voltage in the high-voltage on-board network (13) Provide DC high-voltage voltage of more than 60 volts, - a second on-board network (12), which is an electrical low-voltage on-board network (15) in which at least one vehicle's own low-voltage source (16, 17) is provided, which is set up in the low-voltage on-board network provide a DC low-voltage voltage of 60 volts or less than 60 volts as the vehicle electrical system voltage, - an internal DC voltage converter (18) being provided as a low-voltage source (16) which connects the low-voltage electrical system (15) to the high-voltage electrical system (13), and - an external device connection (37) for exchanging a supply voltage (34) with an external electrical device external to the vehicle unit (20), wherein the third-party device connection (37) has at least one connection contact (37 ') accessible from the outside via an access device, characterized in that the third-party device connection (37) in the motor vehicle (10) has at least one connection circuit (19) of the two vehicle electrical systems (11, 12), whereby the external device connection (37) is connected to an intermediate circuit (47) through the connection circuit (19) and the intermediate circuit (47) is connected to the respective vehicle electrical system (11, 12) by means of a respective DC voltage converter (38, 39) is connected, the respective DC voltage converter (38, 39) on the one hand for exchanging a DC low-voltage voltage, which is less than 60 V, with the intermediate circuit (47) and on the other hand for exchanging the respective vehicle electrical system voltage with the respective vehicle electrical system ( 11, 12) is set up, and a control circuit (40) is set up to measure an amperage of an electrical current (35, 36) that the respective equation Ivoltage converter (38, 39) outputs and / or removes from the respective on-board network (11, 12), to detect and to keep the amount of current below a predetermined threshold value by controlling the respective DC voltage converter (38, 39). Motor vehicle (10) according to Claim 1 , the connection circuit (19) only having the DC-DC converter (38) for the high-voltage on-board network (13) and the control circuit (40) being set up to transfer electrical energy between the external device connection (37) and the low-voltage on-board network (15) Operation of the internal DC voltage converter (18) between the high-voltage on-board network (13) and the low-voltage on-board network (15). Motor vehicle (10) according to one of the preceding claims, wherein the internal DC / DC converter (18) is set up to transmit bidirectionally between the high-voltage on-board network (13) and the low-voltage on-board network (15), and the control circuit (40) is set up to output electrical energy the low-voltage on-board network (15) in the high-voltage on-board network (13). Motor vehicle (10) according to one of the preceding claims, wherein the external device connection (37) and at least one vehicle-internal electrical connection interface (41) for a vehicle-internal additional electrical supply source (21) together via the same intermediate circuit (47) with the at least one DC voltage converter (38, 39) are connected. Motor vehicle (10) according to Claim 4 , an arbiter circuit (46) being provided which is set up to connect the external device connection (37) and the at least one connection interface (41) to the intermediate circuit (47) only in the event that there is a voltage difference between the supply voltage (34 ) and an electrical voltage (45) received via the respective connection interface is smaller in magnitude than a predetermined threshold value (50). Motor vehicle (10) according to Claim 5 wherein the arbiter circuit (46) connects the external device connection (37) and each connection interface (41) to the intermediate circuit (47) via its own switching element (48). Motor vehicle (10) according to Claim 5 or 6th , the arbiter circuit (46) being set up to signal via a communication device (49) to a third-party device unit (20) connected to the third-party device connection (37) and / or an additional supply source (21) connected to a connection interface (41) whether a voltage output allowed is. Motor vehicle (10) according to one of the Claims 1 or 3rd to 7th , wherein both DC voltage converters (38, 39) are provided in the connection circuit (19) and the external device connection (37) is electrically connected to both DC voltage converters (38, 39) via the intermediate circuit (47). Motor vehicle (10) according to one of the preceding claims, wherein the respective DC voltage converter (38, 39) of the connection circuit (19) is designed as a bidirectional converter and the control circuit (40) is set up to use the vehicle electrical system voltage of the respective vehicle electrical system (11, 12), to which the DC voltage converter (38, 39) is connected, to provide an adjustable, regulated charging voltage for a specified external device unit (20) which has its own electrical energy store.

Images