Method for operating a motor vehicle driven at least partially electrically and motor vehicle

Abstract

Charging an EV 1, having a battery 2, a charger 3, a AC power source 33, a high-voltage on-board network 4 and a high-voltage component or heater 14. Here the charging device is connectable to the AC

Description

The present invention relates to a method for operating a vehicle at least partially electrically driven and a motor vehicle. The motor vehicle comprises a battery device and a charging device for charging the battery device by means of alternating current from an external AC source. The motor vehicle comprises a high-voltage onboard network that can be supplied with electrical power by the battery device with at least one high-voltage component. In such an automotive vehicle, it makes sense from an energetic point of view to reduce the operating times of the high-voltage components that are not required for the charging process. Thus, the high-voltage components are typically switched off during the charging process. However, it is disadvantageous that the switched-off high-voltage components are also not available for other uses during the charging process. For example, the electric drive device is switched off completely during the charging process. By this, the drive device cannot be used to heat up the vehicle (referred to as drive heating). During the charging process, the switched-off high-voltage components can only be switched on for safety reasons if the charging process is completely discontinued or shut down. However, this leads to an undesirable delay in the charging process and may also cause undesirable error messages from the charging station. A problem is also that when charging at a charging station for which manual activation was required (e.g. public charging point), the charging process cannot be started again automatically after it has been cancelled. The present invention seeks to provide an improved option to charge a motor vehicle. In particular, the operating times of the high-voltage components are to be kept as low as possible during the charging process. At the same time, the functions of the high-voltage components are also to be available during the charging process. A first aspect of the invention provides a method having the features of claim 1. A second aspect of the invention provides a motor vehicle which is the subject matter of claim 9. Preferred further embodiments of the invention are the subject matter of the subclaims. Further advantages and features of the present invention will emerge from the general description and the description of the example embodiment. The method according to an aspect of the invention is for operating a motor vehicle driven at least partially electrically and, for example, an electric vehicle and / or hybrid vehicle. The motor vehicle is in particular a passenger car. The motor vehicle comprises a battery device and a charging device for charging the battery device by means of alternating current from an external AC power source as part of a charging process (so-called AC charging). The motor vehicle comprises a high-voltage onboard network that can be supplied with electrical power by the battery device with at least one high-voltage component. The charging device comprises an input and an output. The charging device can be connected to the AC power source at the input. At the output, the charging device is connected to the high-voltage on-board network. In particular, during the method, the battery device is recharged with alternating current from the external AC power source by means of the charging device. The method comprises at least the following steps in a suitable number and order: making and / or registering a request to operate the at least one high voltage component during the charging process (in other words, during the charging process, a function of the at least one high-voltage component is requested or registered; in particular, at least at the time of the request for its operation, the high-voltage component is disconnected from the high-voltage on-board network; shutting down the high-voltage on-board system to a voltage-free state, in which the high-voltage on-board network is (galvanically) isolated from the battery device; maintaining the charging process, such that an alternating voltage is applied to the input of the charging device from the AC power source and no power transmission into the high-voltage on-board network takes place at the output of the charging device; energizing the high-volt component to the high-volt on-board network; ramping up the high-voltage on-board network, so that the high-voltage on-board network and thus also the connected high-voltage component is supplied with power by the battery device; continuing the charging process with power transmission through the charging device into the high-voltage on-board network (such that the battery device is charged). Aspects of the present invention offers many advantages. In particular, a significant advantage is provided by the shutdown of the high-voltage on-board network and the maintenance of the charging process during the connection of the high-voltage component. Thus, the high-voltage components can be connected safely and reliably as needed, so that their functions are also available during the charging process. For example, drive heating may occur during the charging process. By switching on as needed, undesirable or unnecessary operating times of the high-voltage components during AC charging are also avoided. In addition, aspects of the invention are uncomplicated in construction and can be easily integrated into already developed or existing motor vehicles. Preferably, a request for heating by means of the high-voltage component is made and / or registered during the charging process. In particular, the operation of a high-voltage component is requested, which can selectively generate heat by its operation. A request for another function of the high-voltage component is also possible. In a particularly preferred configuration, the at least one high-voltage component is configured as an electric drive device. Preferably, the heating is then carried out by means of a targeted power supply to the drive device. In particular, the drive device includes at least one electric machine. Preferably, the heating is carried out by specifically generating losses in the electric machine (without generating a torque). Heating can also be achieved by supplying power to a high-voltage component designed for other purposes. By heating, for example, the drive device and / or the battery device and / or a coolant system and / or an interior space of the motor vehicle can be temperature controlled to a desired temperature during the charging process. It is possible and advantageous that the at least one high-voltage component is configured as an electrical undercarriage device. Preferably, a request to operate the electrical undercarriage device during the charging process is made and / or registered. For example, the actuation may be provided for an undercarriage adjustment or the like. The high-voltage on-board network may comprise at least two and preferably a plurality of high-voltage components. One or more of the high-voltage components can be configured as described in the present case. It is preferred and advantageous that, when the charging process is maintained, a charging current is set with a target value of 0 A. In particular, such a charging current is set at the output of the charging device. In an advantageous further embodiment, at least one contactor device is connected between the output of the charging device and the high-voltage on-board network. The contactor device comprises at least one contactor. In particular, the at least one contactor remains closed when maintaining the charging process. The contactor device in particular allows (galvanic) separation of the output of the charging device from the high-voltage on-board network. Preferably, the contactor device comprises at least two contactors. In particular, upon maintaining the charging process, at least one contactor and preferably only one contactor of the at least two contactors remains closed. In particular, upon maintaining the charging process, at least one contactor of the at least two contactors is opened. However, it is also possible for both contactors to remain closed when maintaining the charging process. In all embodiments, it is preferred that the input of the charging device remains connected to the AC power source when the charging process is maintained. In particular, an alternating voltage is applied to the input of the charging device when maintaining the charging process, and especially during the entire charging process. The motor vehicle according to an aspect of the invention is suitable and configured to be operated according to the method according to an aspect of the invention or one of its further embodiments. In particular, the motor vehicle comprises the components described in the context of the method. In particular, the motor vehicle comprises at least one control device for carrying out the method steps. In particular, the motor vehicle comprises at least one control device. The control device is in particular operatively connected to the battery device and / or the charging device and / or the high-voltage on-board network. In particular, the control device is suitable and designed to carry out the steps of the method. In particular, the control device can control the components connected to the control device. In particular, the control device comprises at least one algorithm for implementing method steps described here. The control device may be integrated into the battery device (for example, as a battery management system) or the vehicle electronics. Further advantages and features of the present invention follow from the example embodiments, which are described below with reference to the accompanying drawings. The following is shown in the drawing: Figure 1 a schematic detail view of a motor vehicle according to an embodiment of the invention, Figure 1 shows a motor vehicle 1 that can be operated according to the method according to an embodiment of the invention, of which only one high-voltage system is shown in detail here for clarity. The motor vehicle 1 is, for example, a batteryelectric passenger car with a battery device 2 configured as a high-voltage battery. The motor vehicle 1 also comprises a high-voltage on-board network 4 with a plurality of high-voltage components 14, which is powered by the battery device 2. The high-voltage components 14 are integrated into the high-voltage on-board system such that they can be connected and disconnected as needed. Furthermore, the motor vehicle 1 comprises a charging device 3 for charging the battery device 2 by means of alternating current from an external AC power source 33 and a wall box, for example. For connection to the AC power source 33, the charging device 3 comprises an input 13. The charging device 3 is connected to the high-voltage on-board network via an output 23. A high-voltage component 14 is configured as a drive device 5 here, which comprises at least one electric machine for a traction drive. Another high-voltage component 14 is configured as an electrical undercarriage device here. The high- voltage on-board network 4 preferably comprises further high-voltage components 14, of which only one is shown here as an example in dotted lines. The motor vehicle 1 is here equipped with a control device 3, which allows a connection of high-voltage components 14 during a running AC charging process without the need to interrupt the charging process. The connection of a high-voltage component 14 is described in more detail below in the example of the drive device 5. By switching on the drive device 5 during the charging process, for example, a so-called drive heating can be carried out in order to temper the vehicle accordingly before traveling (referred to as pre-conditioning). During the charging process, the output 23 is connected to the high-voltage onboard network 4 so that a charging current (via the high-voltage on-board network 4) can flow into the battery device 2. The two contactors 17 of a contactor device 7, which are located between the output 23 and the high-voltage on-board network 4, are closed for this purpose. If a request is made for the drive heating, it is registered by the control device 8. Subsequently, the high-voltage on-board network 14 is shut down to a voltage-free state. For this purpose, the high-voltage on-board network 4 is galvanically isolated from the battery device 2. For example, a contactor device not shown in more detail here is provided for the separation (battery contactor). Meanwhile, the charging process is maintained. The AC voltage of the AC power source 33 is still present at the input 13. A target current of 0 A is provided, for example. However, no power transmission into the high-voltage on-board network 4 takes place at output 23. At least one contactor 17 or even both contactors 17 are still closed. The drive device 5 is now connected to the high-voltage on-board network 4. If the drive device 5 is successfully connected, the high-voltage on-board network 4 is started up again. The drive device 5 can now be powered by battery device 2. The charging process continues, with a charging current greater than zero now being set again.

Claims

1. A method for operating a motor vehicle at least partially electrically driven, comprising a battery device, a charging device for charging the battery device by means of alternating current from an external AC power source as part of a charging process and a high-voltage on-board network, which can be supplied with electrical power by the battery device, with at least one high-voltage component, wherein the charging device is connectable to the AC source at an input and connected to the high-voltage on-board network at an output, comprising the following steps in suitable number and order:- making and / or registering a request to operate the at least one high-voltage component during the charging process;- ramping off the high-voltage on-board system to a voltage-free state, in which the high-voltage on-board network is separated from the battery device;- maintaining the charging process, such that an alternating voltage is applied to the input of the charging device from the AC power source and no power transmission into the high-voltage on-board network takes place at the output of the charging device;- connecting the high-voltage component to the high-voltage on-board network;- ramping up the high-voltage on-board network, such that the connected high-voltage component is powered by the battery device;- continuing the charging process with a power transmission through the charging device into the high-voltage on-board network.

2. The method according to the preceding claim, wherein a request for heating by means of the high-voltage component is made and / or registered during the charging process.

3. The method according to the preceding claim, wherein the at least one high-voltage component is configured as an electric drive device and wherein the heating is carried out by selectively energizing the drive device.

4. The method according to any one of the preceding claims, wherein the at least one high-voltage component is configured as an electrical undercarriage device and wherein a request for actuating the electrical undercarriage device is made and / or registered during the charging process.

5. The method according to any one of the preceding claims, wherein, when the charging process is maintained, a charging current is set at a target value of 0 amperes.

6. The method according to any one of the preceding claims, wherein at least one contactor device with at least one contactor is connected between the output of the charging device and the high-voltage on-board network, and wherein the at least one contactor remains closed when the charging process is maintained.

7. The method according to any one of the preceding claims, wherein, when maintaining the charging process, the input of the charging device remains connected to the AC power source.

8. The motor vehicle according to any one of the preceding claims.

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