Charging adapter for the electrical connection of a motor vehicle with a charging device

Abstract

The invention relates to a charging adapter (2) for electrically connecting a motor vehicle to a charging device (3), wherein the charging adapter is designed to be electrically connected to a first connecting element and simultaneously to a second connecting element, wherein the first and second connecting elements are not connectable to one another, wherein the charging adapter (2) is designed to simultaneously transmit a transmission signal via a first cable element and a charging current via a second cable element from the charging device (3) to the motor vehicle, wherein the charging adapter (2) comprises a temperature sensor (T) and a modulation means (µC), wherein the temperature sensor (T) is designed to determine a temperature of the charging adapter and to transmit it to the modulation means (µC), wherein the modulation means (µC) is designed to modulate a modulation signal onto a transmission signal (PP),wherein the modulation signal includes an indication of temperature.,

Description

[0001] The present invention relates to a charging adapter for electrically connecting a motor vehicle to a charging device according to the preamble of claim 1.

[0002] For such a connection, there are different standards for the connectors in the form of plugs and sockets, for example, the CCS1, CCS2, and NACS standards. To connect the vehicle to a charging device with a connector according to a second standard using a cable with a connector according to a first of the standards, a charging adapter is required.

[0003] WO 2019 / 052 963 A1 discloses such a charging adapter with a temperature sensor. The charging power is controlled based on the temperature sensor's measurement data. Control signals are transmitted wirelessly or via dedicated signal cables.

[0004] DE 10 2017 209 450 A1 discloses a method for determining temperature information regarding a temperature of a charging interface. The charging interface is arranged on a current path between a charging station and an electrical energy storage device of a vehicle. The method comprises determining target information regarding a target charging power provided by the charging station on the current path. Furthermore, the method comprises determining actual information regarding an actual charging power absorbed by the energy storage device from the current path. Furthermore, the method comprises determining the temperature information based on the target information and the actual information.

[0005] US 2019 / 0 030 983 A1 discloses a thermal protection system comprising an electrical circuit and a thermal switch. The electrical circuit transmits an electrical signal between a charge source and a charge receiver during a charging process. The thermal switch is arranged in series with the electrical circuit. The thermal switch opens above a threshold temperature to block the transmission of the electrical signal. By blocking the transmission of the electrical signal, the charging process is stopped.

[0006] In contrast, the present invention is based on the object of simplifying the transmission of information about the measured temperature.

[0007] This object is achieved by a charging adapter according to claim 1, a system according to claim 4 and a method according to claim 8. Embodiments of the invention are specified in the dependent claims.

[0008] The charging adapter is designed to be electrically connected to a first connecting element and, at the same time, to a second connecting element. In the context of this description, a connecting element is understood to mean, in particular, a plug or a socket. The first connecting element and the second connecting element are not electrically connectable to one another. The charging adapter is designed to simultaneously transmit a transmission signal via a first cable element and a charging current via a second cable element from the charging device to the motor vehicle. The charging adapter comprises a temperature sensor and a modulation means. The temperature sensor is designed to determine a temperature of the charging adapter and to transmit it to the modulation means. In the context of this description, this is understood to mean, in particular, that information about the determined temperature is transmitted to the modulation means.This information can, for example, comprise a numerical value. The modulation means is designed to modulate a modulation signal onto the transmission signal. The modulation signal includes an indication of the temperature. In particular, the modulation signal can be temperature-dependent. In this way, it is possible to transmit information about the temperature to the motor vehicle without additional cable elements or other transmission paths. Therefore, a prior art cable designed solely for transmitting the charging current and the transmission signal can be used without adaptation to also transmit information about the measured temperature, because this information is transmitted via the same cable element as the transmission of the transmission signal.

[0009] The transmission signal can be used, for example, to transmit information from the charging device - for example about the charging process - to the motor vehicle.

[0010] According to one embodiment of the invention, the modulation signal can be a pulse-width modulated signal. This is particularly advantageous for transmitting information regarding temperature. For example, a duty cycle used in pulse-width modulation can be temperature-dependent. In particular, it is possible for the duty cycle to be proportional or inversely proportional to the detected temperature, at least in one temperature range.

[0011] According to one embodiment of the invention, the modulation means can be configured to receive energy from the charging current. This allows the modulation means to be supplied with energy in a simple manner. Since the power required by the modulation means is much lower than the power required to charge the motor vehicle's energy storage device, the duration of the charging process is only marginally affected.

[0012] The system according to claim 4 comprises a first connecting element, a third connecting element, the charging adapter according to an embodiment of the invention, and a cable. The cable comprises the first cable element and the second cable element. The first cable element and the second cable element can be electrically insulated from one another. The first connecting element is attached to a first end of the cable. The third connecting element is attached to a second end of the cable. The first connecting element is electrically connected to the third connecting element via the cable. Thus, the cable is electrically connectable to the charging device via the charging adapter, although the first connecting element and the third connecting element are not directly connectable to one another.

[0013] The third connecting element is electrically connectable to a fourth connecting element of the motor vehicle. In this way, the motor vehicle can be connected to the charging device to charge an energy storage device of the motor vehicle. The charging adapter, the first connecting element, the cable, and the third connecting element are designed to transmit a charging current and a transmission signal from the second connecting element to the fourth connecting element.

[0014] The first connecting element can be designed for electrical connection to a fifth connecting element. The fifth connecting element can, for example, be part of another charging device. In this case, the fifth connecting element can differ, in particular, from the second connecting element.

[0015] According to one embodiment of the invention, the transmission signal can be used to transmit information from the charging device to the motor vehicle. For example, information about the status of the charging device can be transmitted.

[0016] According to one embodiment of the invention, the system may comprise the charging device. The charging device may be configured to output the charging current and the transmission signal.

[0017] According to one embodiment of the invention, the system may comprise the motor vehicle. The motor vehicle comprises a control unit configured to receive the modulation signal and to trigger a reduction in the charging current when the temperature reaches a temperature threshold. In particular, it is possible for the reduction in the charging current to be triggered by the temperature reaching the temperature threshold.

[0018] Reducing the current when the temperature reaches the temperature threshold is beneficial to reduce the risk of overheating of the charging adapter. Due to the charging adapter used, the contact resistance for the charging current is increased compared to transferring the charging current without the charging adapter.

[0019] It is possible for the modulation means to be configured to modulate the modulation signal onto the transmission signal only when the temperature reaches or exceeds the temperature threshold. This makes it particularly easy to detect when the temperature reaches or exceeds the temperature threshold using the control unit. As soon as the modulation signal is received, the temperature has reached or exceeded the temperature threshold.

[0020] It is also possible for the control unit to be configured to abort the charging process if the temperature reaches a termination threshold. For example, the duty cycle of the pulse width modulation can be 1 or 0 as soon as the termination threshold is determined as the temperature.

[0021] Preferably, the termination threshold is higher than the temperature threshold. Terminating the charging process is beneficial to reduce the risk of fire.

[0022] It is possible that the duty cycle in the temperature range between the temperature threshold and the termination threshold is proportional or inversely proportional to the temperature.

[0023] In the method according to claim 8, a charging device is electrically connected to an energy storage device of a motor vehicle via a charging adapter, a first connecting element, a cable, and a third connecting element. The charging adapter is electrically connected, preferably directly, to the first connecting element and a second connecting element. The first connecting element is permanently electrically connected to a first end of the cable. The third connecting element is permanently electrically connected to a second end of the cable. In the context of this description, a permanent connection is understood in particular to mean that the respective connecting element can only be removed from the cable non-destructively using a tool.

[0024] The third connecting element is electrically connected to a fourth connecting element of the motor vehicle, preferably directly.

[0025] A charging current is transferred from the charging device to the energy storage device via the second connecting element, the charging adapter, the first connecting element, the cable, the third connecting element, and the fourth connecting element. Due to the use of the charging adapter, there is an additional contact resistance compared to a charging process without the charging adapter, which can lead to additional heating.

[0026] A transmission signal is transmitted during the transmission of the charging current from the charging device to the motor vehicle via the second connecting element, the charging adapter, the first connecting element, the cable, the third connecting element, and the fourth connecting element. Furthermore, the temperature of the charging adapter is determined during the transmission of the charging current. This can be done, for example, using a temperature sensor.

[0027] A modulation signal is modulated onto the transmission signal. The modulation signal includes a temperature indication. For example, the modulation signal can be temperature-dependent. In particular, it is possible for the modulation signal to be modulated onto the transmission signal only when the temperature reaches or exceeds a temperature threshold. Because the modulation signal is modulated onto the transmission signal, no additional cable elements are required to transmit the temperature indication.

[0028] The modulation signal is received by a control unit in the vehicle, which triggers a reduction in the charging current when the temperature reaches the temperature threshold. For example, the event that the temperature reaches the temperature threshold can trigger a reduction in the charging current. This can reduce the risk of the charging adapter overheating.

[0029] According to one embodiment of the invention, information can be transmitted from the charging device to the control unit using the transmission signal.

[0030] It is possible that the method includes one or more features that are described in this description in connection with the charging adapter or the system. For example, if it is described in this context that a component or element is configured for a function, it is possible that this function is performed in an embodiment of the method.

[0031] According to one embodiment of the invention, the control unit can trigger an interruption of the charging current transmission when the temperature reaches a interruption threshold. The interruption threshold is higher than the temperature threshold. Interrupting the charging current transmission reduces the risk of the charging adapter catching fire.

[0032] Further features and advantages of the present invention will become clear from the following description of a preferred embodiment with reference to the accompanying drawings. The same reference numerals are used for identical or similar components, features, or elements and for components, features, or elements with identical or similar functions. Fig. 1 is a schematic diagram of a system according to an embodiment of the invention; and Fig. 2 shows a schematic curve of a duty cycle as a function of a temperature according to an embodiment of the invention.

[0033] An energy storage device 1 of a motor vehicle is electrically connected to a charging device 3 via a system. The system comprises a cable with a first connecting element and a third connecting element at the ends of the cable. The system also includes a charging adapter 2, via which the first connecting element is electrically connected to the charging device 3.

[0034] The third connecting element is electrically connected to the motor vehicle. Optionally, the system 2 can also include the charging device 3 and / or the motor vehicle with the energy storage device 1.

[0035] The cable comprises a first cable element, via which a charging current with a charging voltage HV is transmitted from the charging device 3 to the energy storage device 1. The first cable element comprises a positive conductor HV+ and a negative conductor HV-.

[0036] The cable also includes a second cable element, via which a transmission signal PP is transmitted from the charging device 3 to the energy storage device 1. The second cable element is electrically insulated from the first cable element. The transmission of the transmission signal PP can be switched on and off by means of a switching device S1.

[0037] The charging adapter 2 comprises a modulation device (µC), which can be implemented, for example, as a microcontroller. The modulation device (µC) is supplied with energy from the charging current via a voltage converter 4. The voltage converter 4 converts the charging voltage HV into a lower voltage.

[0038] A temperature sensor T detects the temperature of the charging adapter and transmits the measured temperature to the modulation device µC. When the measured temperature reaches a temperature threshold T1, the modulation device µC modulates a pulse-width modulated modulation signal onto the transmission signal PP. The modulation signal includes an indication of the measured temperature.

[0039] As the temperature continues to rise, the duty cycle of the modulation signal changes. Fig. As can be seen from Figure 2, the duty cycle is proportional to the measured temperature if the temperature is greater than the temperature threshold T1. When the temperature reaches the termination threshold T2, the duty cycle is 1.

[0040] The transmission signal PP and the modulated modulation signal are transmitted to a control unit in the vehicle. Upon receipt of the modulation signal with a duty cycle of 1, the control unit interrupts the transmission of the charging current. This reduces the risk of fire due to overheating of the charging adapter.

[0041] Upon receiving the modulation signal with a duty cycle of less than 1, the control unit triggers a reduction in the charging current. This reduces the risk of overheating of the charging adapter.

[0042] Transmitting the temperature indication of the charging adapter 2 with the modulation signal is advantageous because a cable and connectors from the prior art can be used. No additional transmission path is required for the modulation signal.

Claims

[1] Charging adapter (2) for electrically connecting a motor vehicle to a charging device (3), wherein the charging adapter is designed to be electrically connected to a first connecting element and simultaneously to a second connecting element, wherein the first and the second connecting element are not electrically connectable to one another, wherein the charging adapter (2) is designed to simultaneously transmit a transmission signal via a first cable element and a charging current via a second cable element from the charging device (3) to the motor vehicle, wherein the charging adapter (2) comprises a temperature sensor (T) and a modulation means (µC), wherein the temperature sensor (T) is designed to determine a temperature of the charging adapter and to transmit it to the modulation means (µC), characterized bythat the modulation means (µC) is designed to modulate a modulation signal onto a transmission signal (PP), wherein the modulation signal comprises an indication of the temperature. [2] Charging adapter (2) according to claim 1, characterized by that the modulation signal is a pulse width modulated signal. [3] Charging adapter (2) according to one of the preceding claims, characterized by that the modulation means is designed to receive energy from the charging current. [4] System comprising a charging adapter (2) according to one of the preceding claims, a first connecting element, a third connecting element and a cable, wherein the cable comprises the first cable element and the second cable element, wherein the first connecting element is fastened to a first end of the cable, wherein the third connecting element is fastened to a second end of the cable, wherein the first connecting element is electrically connected to the third connecting element via the cable, wherein the second connecting element is a connecting element of the charging device (3), wherein the third connecting element is electrically connectable to a fourth connecting element of the motor vehicle, wherein the charging adapter (2), the first connecting element, the cable and the third connecting element are designed to transmit the charging current and the transmission signal (PP) from the second connecting element to the fourth connecting element. [5] System according to the previous claim, characterized by that the transmission signal serves to transmit information from the charging device (3) to the motor vehicle. [6] System according to one of the preceding two claims, characterized by that the system (2) comprises the charging device (3), wherein the charging device (3) is designed to output the charging current and the transmission signal. [7] System according to one of the preceding three claims, characterized by that the system (2) comprises the motor vehicle, wherein the motor vehicle comprises a control unit which is designed to receive the modulation signal and to trigger a reduction of a current intensity of the charging current when the temperature reaches a temperature threshold value (T1). [8] Method for charging an energy storage device (1) of a motor vehicle, comprising the following steps. - Electrical connection of a charging device (3) to the energy storage device (1) of the motor vehicle via a charging adapter (2), a first connecting element, a cable and a third connecting element, wherein the charging adapter (2) is electrically connected to the first connecting element and a second connecting element of the charging device (3), wherein the first connecting element is fixedly electrically connected to a first end of the cable, wherein the third connecting element is fixedly electrically connected to a second end of the cable, and wherein the third connecting element is electrically connected to a fourth connecting element of the motor vehicle, - transmission of a charging current from the charging device (3) via the second connecting element, the charging adapter (2), the first connecting element, the cable, the third connecting element and the fourth connecting element to the energy storage device (1); - transmission of a transmission signal (PP) from the charging device (3) via the second connecting element, the charging adapter (2), the first connecting element, the cable, the third connecting element and the fourth connecting element to the motor vehicle during the transmission of the charging current; - Determination of a temperature of the charging adapter (2) during the transmission of the charging current; - modulating a modulation signal onto the transmission signal (PP), the modulation signal comprising an indication of the temperature; - Reception of the modulation signal by a control unit of the motor vehicle; and - Triggering a reduction in the charging current intensity by the control unit when the temperature reaches a temperature threshold (T1). [9] Method according to the previous claim, characterized bythat information is transmitted from the charging device (3) to the control unit using the transmission signal (PP). [10] Method according to one of the two preceding claims, characterized by that the control unit triggers an interruption of the transmission of the charging current when the temperature reaches an interruption threshold (T2).

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