Motor vehicle with low-voltage charging electronics for charging the on-board battery at an external charging unit, and a system for charging an on-board battery.

Abstract

The present invention relates to an electrically or partially electrically powered motor vehicle (1) with a low-voltage electrical system, wherein the low-voltage electrical system operates at a first voltage level, and with a high-voltage electrical system, wherein the high-voltage electrical system operates at a second voltage level, the second voltage level being higher in magnitude than the first voltage level. The motor vehicle has a charging socket (4), wherein an electrical connection to an external charging unit for charging a high-voltage battery can be established by connecting the charging socket (4) to a corresponding charging plug.The charging socket (4) has one or more external conductor connections (L1, L2, L3) and a neutral conductor connection (N) for transmitting a charging current as well as a control pilot connection (CP) for transmitting a control pilot signal provided by the charging unit in the form of a low-voltage voltage signal and wherein a low-voltage charging electronics, which detects the voltage level of the low-voltage vehicle electrical system, compares it with a target voltage and, if the target voltage is undershot, provides a charging current to charge the vehicle electrical system battery (2).

Description

[0001] The present invention relates to a motor vehicle with low-voltage charging electronics for charging the on-board power supply battery using a charging unit external to the vehicle. Furthermore, the present invention relates to a system for charging an on-board power supply battery of an electrically or partially electrically powered motor vehicle.

[0002] Electric or partially electric motor vehicles typically comprise a low-voltage electrical system and a high-voltage electrical system, with the high-voltage electrical system operating at a higher voltage than the low-voltage electrical system. The high-voltage electrical system typically supplies electrical energy to the electric drives. The low-voltage electrical system typically supplies electrical energy to comfort functions such as air conditioning and entertainment systems, such as multimedia systems, and possibly other electrical components of the vehicle.

[0003] Charging methods and charging systems for charging a high-voltage battery of an electric or partially electric motor vehicle are known from the prior art. For example, WO 2021 / 012320 A1 describes a charging device in which a voltage signal applied to a CP signal line is used to supply a control system of a motor vehicle and / or a charging system of the motor vehicle with electrical energy. EP 4 173 879 A1, EP 3 798 045 A1, DE 10 2021 108 004 A1, and DE 10 2019 132 027 A1 disclose further prior art.

[0004] It can happen that the on-board power supply battery, which is designed as a low-voltage battery and serves to provide the necessary voltage in the low-voltage on-board power supply, goes into low voltage and then switches off. The on-board power supply battery is usually switched off to prevent deep discharge and thus damage to the on-board power supply battery. In such a case, no energy is left in the low-voltage on-board power supply. This often leads to the motor vehicle being electrically inoperable. This can possibly occur when the vehicle is locked. In such a case, the problem is that there is no longer any access to the on-board power supply battery, in particular to the jump-start point of the on-board power supply battery, in order to supply the on-board power supply battery with external electrical energy for the purpose of charging and / or bridging the on-board power supply battery.

[0005] The object of the present invention is to provide a novel motor vehicle that enables charging of the on-board battery using an external charging unit. Furthermore, the object of the present invention is to provide a corresponding system.

[0006] These problems are solved by the subject matter of the independent patent claims. Advantageous further developments are the subject matter of the dependent claims.

[0007] The motor vehicle according to the invention is an electrically or partially electrically powered motor vehicle. The motor vehicle has a low-voltage electrical system, wherein the low-voltage electrical system is operated at a first voltage level, wherein the motor vehicle has a high-voltage electrical system, wherein the high-voltage electrical system is operated at a second voltage level, wherein the second voltage level is higher in magnitude than the first voltage level, wherein the low-voltage electrical system comprises an on-board electrical system battery and the high-voltage electrical system comprises a traction battery, wherein the motor vehicle has a charging socket, wherein by coupling a charging plug corresponding to the charging socket to the charging socket, an electrical connection to a charging unit external to the motor vehicle can be established for charging the traction battery, wherein the charging socket has one or more outer conductor connections, frequently also referred to as phase conductor connections,and a neutral conductor connection for transmitting a charging current provided by the charging unit for charging the traction battery, wherein the charging socket has a control pilot connection, hereinafter referred to as the CP connection, for transmitting a control pilot signal provided by the charging unit in the form of a low-voltage signal, in particular in the form of a low-voltage AC signal, from the charging unit to the motor vehicle, wherein the charging socket has a protective conductor connection, hereinafter referred to as the PE connection, wherein the motor vehicle has low-voltage charging electronics for charging the on-board power supply battery, wherein the low-voltage charging electronics are connected to the PE connection and the CP connection, wherein the low-voltage charging electronics comprises an electronic unit, wherein the electronic unit is configured to detect the voltage level of the low-voltage on-board power supply and to compare it with a target voltage,When the target voltage is undershot, the low-voltage charging electronics provides a charging current to charge the on-board battery using the control pilot signal present at the CP connection.

[0008] The basic idea of ​​the solution according to the invention is therefore to use the voltage signal present at the CP terminal to charge the on-board network battery when required, i.e. when the on-board network battery is undervoltage.

[0009] Preferably, a pulse-width-modulated 12 V AC signal is transmitted from the vehicle-external charging unit to the motor vehicle via the CP connection. This CP AC signal serves to transmit information regarding the maximum charging current available from the charging unit to the vehicle's internal high-voltage charging electronics. The vehicle's internal high-voltage charging electronics are used to charge the traction battery, with the corresponding charging current being provided to the lines of the charging plug of the charging unit, which can be plugged into the charging socket, corresponding to the phase conductor connections and the neutral conductor connection.

[0010] The traction battery is preferably a high-voltage battery.

[0011] If the electronic unit of the low-voltage charging electronics detects that the vehicle electrical system voltage is greater than or equal to the target voltage, charging of the vehicle electrical system battery can be terminated via the low-voltage charging electronics, and the vehicle electrical system battery can be switched from the low-voltage state to normal operating mode. It is then possible to access vehicle functions, such as door opening functions and / or diagnostic functions, which are supplied with electrical energy via the low-voltage vehicle electrical system.

[0012] In a particularly preferred embodiment, it is provided that the low-voltage charging electronics comprise a relay, wherein the relay is formed in a current path to the CP connection, wherein the low-voltage charging electronics is configured to close the relay when the target voltage is undershot.

[0013] In a particularly preferred embodiment, the low-voltage charging electronics are configured to draw an operating current for operating the low-voltage charging electronics via the CP connection. Such a design has the advantage that the low-voltage charging electronics does not need to be supplied with electrical energy from an internal vehicle energy source, such as a separate battery for the low-voltage charging electronics. Instead, the power is supplied via the low-voltage voltage provided by the charging unit at the CP connection.

[0014] It is considered particularly advantageous if the on-board network battery is connected to the PE terminal of the charging socket.

[0015] In a particularly preferred embodiment, the low-voltage charging electronics are designed to transmit the control pilot signal directly to the on-board power supply battery when the target voltage is undershot and thus to use it directly to charge the on-board power supply battery.

[0016] It is considered particularly advantageous if the charging socket has a proxy pilot connection, hereinafter referred to as PP connection.

[0017] In a particularly preferred embodiment, the charging socket is designed as a Type 2 charging socket according to the international standard IEC 62196.

[0018] It is considered particularly advantageous if the low-voltage electrical system is a 12V electrical system.

[0019] The system according to the invention is a system for charging an on-board power supply battery of an electrically or partially electrically powered motor vehicle, wherein the system comprises the motor vehicle and a charging unit external to the motor vehicle, wherein the motor vehicle has a low-voltage on-board power supply, wherein the low-voltage on-board power supply is operated at a first voltage level, wherein the motor vehicle has a high-voltage on-board power supply, wherein the high-voltage on-board power supply is operated at a second voltage level, wherein the second voltage level is higher in magnitude than the first voltage level, wherein the low-voltage on-board power supply comprises an on-board power supply battery and the high-voltage on-board power supply comprises a traction battery, wherein the motor vehicle has a charging socket, wherein an electrical connection to the charging unit external to the motor vehicle can be established by coupling a charging plug corresponding to the charging socket to the charging socket,wherein the charging socket has one or more outer conductor connections and a neutral conductor connection for transmitting a charging current provided by the charging unit for charging the traction battery, wherein the charging socket has a control pilot connection, hereinafter referred to as CP connection, for transmitting a control pilot signal provided by the charging unit in the form of a low-voltage signal, in particular in the form of a low-voltage AC signal, from the charging unit to the motor vehicle, wherein the charging socket has a protective conductor connection, hereinafter referred to as PE connection, wherein the motor vehicle has low-voltage charging electronics for charging the on-board network battery, wherein the low-voltage charging electronics are connected to the PE connection and the CP connection, wherein the low-voltage charging electronics comprises an electronic unit, wherein the electronic unit is configured toto record the voltage level of the low-voltage vehicle electrical system and compare it with a target voltage; if the target voltage is undershot, the low-voltage charging electronics provides a charging current to charge the vehicle electrical system battery using the control pilot signal applied to the CP connection.

[0020] In an alternative embodiment, the system for charging an on-board power supply battery of an electrically or partially electrically powered motor vehicle comprises the motor vehicle, an adapter plug with a USB port, and an energy donor coupled to the USB port. The motor vehicle has a low-voltage on-board power supply, the low-voltage on-board power supply being operated at a first voltage level. The motor vehicle has a high-voltage on-board power supply, the high-voltage on-board power supply being operated at a second voltage level, the second voltage level being higher in magnitude than the first voltage level. The low-voltage on-board power supply comprises an on-board power supply battery and the high-voltage on-board power supply comprises a traction battery. The motor vehicle has a charging socket, an electrical connection to a charging unit external to the motor vehicle being able to be established by coupling a charging plug corresponding to the charging socket to the charging socket.wherein the charging socket has one or more outer conductor connections and a neutral conductor connection for transmitting a charging current provided by the charging unit for charging the traction battery, wherein the charging socket has a control pilot connection, hereinafter referred to as CP connection, for transmitting a control pilot signal provided by the charging unit in the form of a low-voltage signal, in particular in the form of a low-voltage AC signal, from the charging unit to the motor vehicle, wherein the charging socket has a protective conductor connection, hereinafter referred to as PE connection, wherein the motor vehicle has low-voltage charging electronics for charging the on-board network battery, wherein the low-voltage charging electronics are connected to the PE connection and the CP connection, wherein the low-voltage charging electronics comprises an electronic unit, wherein the electronic unit is configured toto detect the voltage level of the low-voltage vehicle electrical system and compare it with a target voltage, wherein, if the target voltage is undershot, the low-voltage charging electronics provide a charging current for charging the vehicle electrical system battery using a voltage applied to the CP connection, wherein the adapter plug is coupled to the charging socket in such a way that the voltage applied to the CP connection is provided by the energy donor.

[0021] In a preferred embodiment, the energy donor is a smartphone or a power bank or a charger for a smartphone.

[0022] The low-voltage signals are preferably a low-voltage AC signal, in particular a pulse-width-modulated low-voltage AC signal, preferably a pulse-width-modulated 12 V AC signal.

[0023] The statements regarding the design of the motor vehicle apply accordingly to the system according to the invention and vice versa.

[0024] The following figures illustrate the invention in more detail using an exemplary embodiment, without being limited to this embodiment. They show: Fig. 1 an electrically powered motor vehicle and a vehicle-external charging unit in a schematic representation, Fig. 2 a connection diagram of a charging socket and a low-voltage charging electronics for charging a vehicle's on-board battery.

[0025] The Fig.1 shows an electrically powered motor vehicle 1, wherein the motor vehicle 1 has a low-voltage electrical system, wherein the low-voltage electrical system is operated at a first voltage level. The voltage of the low-voltage electrical system is provided by an on-board power supply battery 2. During normal operation of the low-voltage electrical system, it is operated at a voltage level of approximately 12 V. The motor vehicle 1 further has a high-voltage electrical system, wherein the voltage for the high-voltage electrical system is provided by a traction battery 3 of the motor vehicle 1, which is not identical to the on-board power supply battery 2 and is a high-voltage battery. The high-voltage electrical system supplies, for example, electric drives of the motor vehicle 1 with electrical energy. The voltage level of the high-voltage electrical system is higher in magnitude than the voltage level of the low-voltage electrical system.The motor vehicle 1 has a charging socket 4 for charging the traction battery 3 of the motor vehicle 1. This charging socket 4 is a Type 2 charging socket according to the international standard IEC 62196. Accordingly, the charging socket 4 has seven connections or seven electrical contacts, namely a protective conductor connection PE, hereinafter referred to as the PE connection, a control pilot connection CP, hereinafter referred to as the CP connection, a proxy pilot connection PP, hereinafter referred to as the PP connection, furthermore three outer conductor connections L1, L2, L3 and a neutral conductor connection N. A corresponding connection plug 5 can be plugged into the charging socket 4 and can thus be coupled to the charging socket 4 both mechanically and electrically, wherein this connection plug 5 forms a component of a charging cable that is connected or connectable to a charging unit 6 external to the motor vehicle.A control pilot signal provided by the charging unit 6 is transmitted via the CP connection CP in the form of a pulse-width-modulated 12 V AC signal to the high-voltage charging electronics of the motor vehicle 1. For example, the current available at the charging unit 6 can be transmitted to the motor vehicle 1 via the control pilot signal. Via the PP connection PP, both the charging unit 6 and the motor vehicle 1 can detect whether electrical contact exists between the motor vehicle 1 and the charging unit 6, and also how high the connected charging cable may be loaded. For this purpose, a fixed resistor is installed in the charging plug 5 between the PP conductor and the PE conductor. The value of this resistor indicates the cross-section of the charging cable wires, which in turn determines the load capacity of the charging cable.

[0026] The motor vehicle 1 has low-voltage charging electronics 7 for charging the on-board electrical system battery 2. The low-voltage charging electronics 7 represent an emergency charging unit, via which an on-board electrical system battery 2 that is undervoltage and possibly switched off due to the undervoltage can be charged via the external charging unit 6. For this purpose, the low-voltage charging electronics 7 is connected to the PE connection PE and the CP connection CP of the charging socket 4, wherein the low-voltage charging electronics 7 comprises an electronic unit, wherein the electronic unit is configured to detect the voltage level of the low-voltage on-board electrical system and to compare it with a target voltage, wherein if the target voltage, which in this case is approximately 12 V, is undershot, the low-voltage charging electronics 7 provides a charging current for charging the on-board electrical system battery 2 using the control pilot signal present at the CP connection CP.

[0027] For this purpose, the low-voltage charging electronics 7 has a switchable relay 8, wherein this relay 8 is formed in a current path to the CP connection CP, wherein the low-voltage charging electronics 7 is configured to close the relay 8 when the target voltage is undershot in order to establish a current path between a positive connection of the vehicle electrical system battery 2 and the CP connection CP of the charging socket 4.

[0028] The electronic unit of the low-voltage charging electronics 7 continuously checks whether the vehicle electrical system voltage is greater than 12 V. If this is the case, relay 8 remains open. If the electronic unit detects that the vehicle electrical system voltage is less than 12 V, relay 8 is closed, and a charging current flows into the low-voltage vehicle electrical system to charge the vehicle electrical system battery 2. After a certain amount of time, the vehicle electrical system battery 2 is charged to such an extent that it automatically switches to normal operating mode or is switched to normal operating mode via a signal sent by the low-voltage charging electronics 7. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] WO 2021 / 012320 A1

[0003] EP 4 173 879 A1

[0003] EP 3 798 045 A1

[0003] DE 10 2021 108 004 A1

[0003] DE 10 2019 132 027 A1

[0003]

Claims

[1] Electrically or partially electrically powered motor vehicle (1), wherein the motor vehicle (1) has a low-voltage electrical system, wherein the low-voltage electrical system is operated at a first voltage level, wherein the motor vehicle (1) has a high-voltage electrical system, wherein the high-voltage electrical system is operated at a second voltage level, wherein the second voltage level is higher in magnitude than the first voltage level, wherein the low-voltage electrical system comprises an on-board power supply battery (2) and the high-voltage electrical system comprises a traction battery (3), wherein the motor vehicle (1) has a charging socket (4), wherein by coupling a charging plug (5) corresponding to the charging socket (4) to the charging socket (4), an electrical connection to a charging unit (6) external to the motor vehicle can be established for charging the traction battery (3), wherein the charging socket (4) has one or more outer conductor connections (L1, L2,L3) and a neutral conductor connection (N) for transmitting a charging current provided by the charging unit (6) for charging the traction battery (3), wherein the charging socket (4) has a control pilot connection (CP) for transmitting a control pilot signal provided by the charging unit (6) in the form of a low-voltage signal from the charging unit (6) to the motor vehicle (1), wherein the charging socket (4) has a protective conductor connection (PE), wherein the motor vehicle (1) has low-voltage charging electronics (7) for charging the on-board power supply battery (2), wherein the low-voltage charging electronics (7) is connected to the protective conductor connection (PE) and the control pilot connection (CP), wherein the low-voltage charging electronics (7) comprises an electronic unit, wherein the electronic unit is configured to detect the voltage level of the low-voltage on-board power supply and to compare it with a target voltage,wherein, when the target voltage is undershot, the low-voltage charging electronics (7) provides a charging current for charging the on-board network battery (2) using the control pilot signal present at the control pilot connection (CP). [2] Electrically or partially electrically driven motor vehicle (1) according to claim 1, wherein the low-voltage charging electronics (7) comprises a relay (8), wherein the relay (8) is formed in a current path to the control pilot connection (CP), wherein the low-voltage charging electronics (7) is designed to close the relay (8) when the target voltage is undershot. [3] Electrically or partially electrically driven motor vehicle (1) according to claim 1 or 2, wherein the low-voltage charging electronics (7) are designed to receive an operating current for operating the low-voltage charging electronics (7) via the control pilot connection (CP). [4] Electrically or partially electrically driven motor vehicle (1) according to one of claims 1 to 3, wherein the on-board network battery (2) is connected to the protective conductor connection (PE) of the charging socket (4). [5] Electrically or partially electrically driven motor vehicle (1) according to one of claims 1 to 4, wherein the low-voltage charging electronics (7) are designed to transmit the control pilot signal directly to the on-board power supply battery (2) when the target voltage is undershot in order to charge the on-board power supply battery. [6] Electrically or partially electrically driven motor vehicle (1) according to one of claims 1 to 5, wherein the charging socket (4) is designed as a Type 2 charging socket according to the international standard IEC 62196. [7] Electrically or partially electrically driven motor vehicle (1) according to one of claims 1 to 6, wherein the low-voltage electrical system is a 12V electrical system. [8] A system for charging an on-board power supply battery (2) of an electrically or partially electrically powered motor vehicle (1), wherein the system comprises the motor vehicle (1) and a charging unit (6) external to the motor vehicle, wherein the motor vehicle (1) has a low-voltage on-board power supply, wherein the low-voltage on-board power supply is operated at a first voltage level, wherein the motor vehicle (1) has a high-voltage on-board power supply, wherein the high-voltage on-board power supply is operated at a second voltage level, wherein the second voltage level is higher in magnitude than the first voltage level, wherein the low-voltage on-board power supply comprises an on-board power supply battery (2) and the high-voltage on-board power supply comprises a traction battery (3), wherein the motor vehicle (1) has a charging socket (4), wherein an electrical connection to the charging unit (6) external to the motor vehicle can be established by coupling a charging plug (5) corresponding to the charging socket (4) to the charging socket (4),wherein the charging socket (4) has one or more outer conductor connections (L1, L2, L3) and a neutral conductor connection (N) for transmitting a charging current provided by the charging unit (6) for charging the traction battery (3), wherein the charging socket (4) has a control pilot connection (CP) for transmitting a control pilot signal provided by the charging unit (6) in the form of a low-voltage signal from the charging unit (6) to the motor vehicle (1), wherein the charging socket (4) has a protective conductor connection (PE), wherein the motor vehicle (1) has low-voltage charging electronics (7) for charging the on-board network battery (2), wherein the low-voltage charging electronics (7) is connected to the protective conductor connection (PE) and the control pilot connection (CP), wherein the low-voltage charging electronics (7) comprises an electronic unit, wherein the electronic unit is configured toto detect the voltage level of the low-voltage vehicle electrical system and to compare it with a target voltage, wherein if the target voltage is undershot, the low-voltage charging electronics (7) provides a charging current for charging the vehicle electrical system battery (2) using the control pilot signal applied to the control pilot connection (CP). [9] System for charging an on-board power supply battery (2) of an electrically or partially electrically powered motor vehicle (1), wherein the system comprises the motor vehicle (1), an adapter plug with a USB port and an energy donor coupled to the USB port, wherein the motor vehicle (1) has a low-voltage on-board power supply, wherein the low-voltage on-board power supply is operated at a first voltage level, wherein the motor vehicle (1) has a high-voltage on-board power supply, wherein the high-voltage on-board power supply is operated at a second voltage level, wherein the second voltage level is higher in magnitude than the first voltage level, wherein the low-voltage on-board power supply comprises an on-board power supply battery (2) and the high-voltage on-board power supply comprises a traction battery (3), wherein the motor vehicle (1) has a charging socket (4),wherein by coupling a charging plug (5) corresponding to the charging socket (4) to the charging socket (4), an electrical connection to a charging unit (6) external to the motor vehicle can be established, wherein the charging socket (4) has one or more outer conductor connections (L1, L2, L3) and a neutral conductor connection (N) for transmitting a charging current provided by the charging unit (6) for charging the traction battery (3), wherein the charging socket (4) has a control pilot connection (CP) for transmitting a control pilot signal provided by the charging unit (6) in the form of a low-voltage signal from the charging unit (6) to the motor vehicle (1), wherein the charging socket (4) has a protective conductor connection (PE), wherein the motor vehicle (1) has low-voltage charging electronics (7) for charging the on-board network battery (2), wherein the low-voltage charging electronics (7) is connected to the protective conductor connection (PE) and the control pilot connection (CP),wherein the low-voltage charging electronics (7) comprises an electronic unit, wherein the electronic unit is configured to detect the voltage level of the low-voltage vehicle electrical system and to compare it with a target voltage, wherein, when the target voltage is undershot, the low-voltage charging electronics (7) provides a charging current for charging the vehicle electrical system battery (2) using a voltage applied to the control pilot connection (CP), wherein the adapter plug is coupled to the charging socket (4) such that the voltage applied to the control pilot connection (CP) is provided by the energy donor. [10] The system of claim 9, wherein the energy donor is a smartphone or a power bank or a charger for a smartphone.

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