DE102019200909A1 - Method for charging a configurable vehicle battery and vehicle electrical system - Google Patents

Abstract

A method for charging a configurable vehicle accumulator (AK) comprises the steps: detecting a number of phases of an alternating voltage at an alternating current connection (WA); Converting the AC voltage into a rectified DC voltage by means of a rectifier (GR); and charging the vehicle accumulator (AK) by means of the rectified DC voltage. In the case of a first phase number, the vehicle accumulator (AK) is configured in accordance with a first configuration and in the case of a second phase number which is different from the first, the vehicle accumulator (AK) is configured in accordance with a second, different configuration before the conversion and charging is carried out a vehicle electrical system (BN) described to carry out the method.

Description

Vehicles with an electric drive, that is purely electric vehicles and hybrid vehicles, have an accumulator. It is known to transmit electrical power to the rechargeable battery by means of an AC charging station in order to charge it. If the battery voltage differs significantly from the rectified AC voltage, a converter is usually used to adapt the different voltage levels. Since charging stations or other charging interfaces provide specific voltages, which can differ depending on the design of the charging station or charging interface - particularly with regard to different phase numbers - the task is to make it possible to charge differently with different voltages.

This object is achieved by the subject matter of the independent claims. Further features, embodiments, properties and advantages result from the dependent claims, the description and the figures.

It is proposed to configure the accumulator differently with different (actively used) phase numbers of an AC connection, different configurations of the accumulator leading to different terminal voltages (i.e. total voltages of the accumulator units of the accumulator). In order to adapt to the voltage level of the direct voltage, which was generated from the alternating voltage of the alternating current connection by rectification, the terminal voltage of the accumulator is adapted by adapting its configuration. Accumulators can be configured in parallel, in which case accumulator units of the accumulator (i.e. subgroups of accumulator cells) are connected to one another in parallel. Accumulators can be configured in series, in which case accumulator units of the accumulator (i.e. subgroups of accumulator cells) are connected in series. The cells within the accumulator units or the subgroups can (not configurable) be connected completely in series, connected completely in parallel, or connected to one another in a combination of series and parallel connection (for example as a parallel connection of series connections of cells or as a series connection of Parallel connection of cells).

For example, the AC voltage can be single-phase at an AC voltage connection or can be three-phase, for example depending on the implementation of an AC voltage interface, for example a socket. If the AC voltage is single-phase with an effective voltage of 230 V, the top of the network is approx. 325 V; the rectified voltage can then be approximately 450 V, in particular if the AC voltage is rectified by a power factor correction filter. This would match a battery voltage of 235 V - 410 V to charge the battery. In this case, the accumulator would be in a first configuration, which provides for a lower (terminal) voltage of the accumulator compared to a second configuration. The first configuration can therefore be a parallel configuration. On the other hand, if the AC voltage is three-phase with an effective voltage of 230 V, the net crest value is approx. 565 V (due to the higher chaining factor); the rectified voltage can then be approximately 850 V, in particular if the AC voltage is rectified by a power factor correction filter. This would match a battery voltage of 470 V - 820 V to charge the battery. In this case, the accumulator would be in the second configuration, which provides for a higher (terminal) voltage of the accumulator compared to the first configuration. The second configuration can therefore be a serial configuration, this example relating to a parallel / serial configuration of two accumulator units. The configuration of the rechargeable battery is therefore used to adapt the rectified voltage or the rectified voltage range to the terminal voltage of the accumulator, in order to enable adaptation to different charging processes (by means of a voltage source external to the vehicle).

Since the configuration of the accumulator can thus be used to adapt to a rectified voltage of an AC voltage source, the requirements for further adaptation to other components, for example to an (optional) converter or to a controllable rectifier, are no longer as high. In particular, this makes it possible that neither DC voltage converters (if present) nor rectifiers have to work in a particularly wide voltage range, and in particular have to work in subregions in which the components in question have a lower efficiency than in other subregions. In particular, it is possible that the voltage adjustment is carried out solely by means of the controllable rectifier and the adjustable configuration.

A method for charging a configurable vehicle accumulator is thus proposed as follows. First, a number of phases of an alternating voltage at an alternating current connection is detected. However, the generally available number of phases is not recorded, but rather the number of active phases actually supplied to a rectifier. So if at one three-phase connection only one phase is rectified, the number of phases is one, since the number of active phases is one. If all three phases are used for rectification, there is also a higher chaining factor and thus also a higher number of active phases, namely a phase number of three. The AC connection is in particular an AC connection of a vehicle electrical system, in which the vehicle accumulator is also provided. The number of (active) phases can be recorded or set using a control unit. The latter case corresponds to the recorded phase number of the set phase number.

Furthermore, the AC voltage is converted into a first DC voltage by means of a rectifier. In particular, the AC voltage is converted into the first DC voltage by means of a controllable rectifier. The rectifier preferably has a step-up function and thus generates a higher rectified voltage than an uncontrolled full-wave rectifier (after smoothing) would produce. The rectifier can include temporary storage elements such as coils and can in particular be designed as a power factor correction filter, for example as a Vienna rectifier. The rectifier is preferably a controllable rectifier.

In one embodiment, the rectified DC voltage is converted into a converted DC voltage by means of a DC voltage converter. This is used to adapt to a currently required voltage on the vehicle battery. The DC-DC converter can be set up to control or regulate the charging process of the vehicle battery. The converted DC voltage is applied to the accumulator (via the configuration circuit). Another embodiment provides that the rectified DC voltage (without conversion) is applied to the accumulator or to the configuration circuit. The rectified DC voltage can therefore be applied to the accumulator (in particular via the configuration circuit) directly or via a DC voltage converter.

The vehicle accumulator is charged by applying the rectified DC voltage (i.e. the output voltage of the rectifier) to the vehicle accumulator, in particular if no converter is provided between the rectifier and the accumulator. The vehicle battery is charged by applying the converted DC voltage (i.e., the output voltage of the DC-DC converter) to the vehicle battery when the DC-DC converter is provided between the rectifier and the battery.

In embodiments in which the DC voltage converter is provided or the rectified voltage is converted by means of the DC voltage converter, the DC voltage converter can therefore also be used to adapt the rectified DC voltage to a target charging voltage or to a nominal voltage of the vehicle battery. In addition to (or instead of) the adaptation by means of the DC voltage converter (and possibly also the rectifier), a configuration of the vehicle accumulator can contribute to the adaptation as follows. In the case of a first number of phases, the vehicle accumulator is configured in accordance with a first configuration. In a second, different (i.e. larger or smaller) phase number, the vehicle accumulator is configured according to a different (i.e. second, different to the first configuration) configuration. The configuration is set before the loading and conversion are carried out. After the number of phases has been recorded, the configuration is carried out, with the conversion and the loading taking place after the configuration.

In a first embodiment, the first phase number is preferably smaller than the second phase number, and the first configuration (which is set for the first phase number) is a parallel configuration of the vehicle accumulator. In a second embodiment, the first phase number is smaller than the second phase number, and the first configuration (which is set for the first phase number) is a serial configuration of the vehicle accumulator. The second embodiment is used in particular if the vehicle accumulator has a state of charge below a threshold value, while the first embodiment is used if the state of charge is not below the threshold value. Both configurations can be implemented as different charging phases of the same method. The threshold value can correspond to a state of charge in which the terminal voltage of the battery in parallel (corresponding to the terminal voltage of an accumulator unit) is not more than 60%, 55% or 50% of the nominal voltage. The threshold value can be, for example, approximately 215 V, 220 V, 225 V or 230 V.

Furthermore, in the second phase number, the second configuration is carried out as a serial configuration of the vehicle accumulator. In other words, in the first phase number, which is less than the second phase number, a parallel configuration of the vehicle battery is provided as the first configuration of the vehicle battery. This is done when the first phase number is detected. If the second phase number that is greater than the first phase number is detected, then a serial configuration of the vehicle accumulator is provided as the second configuration. A parallel configuration of the vehicle battery is provided by connecting a first battery unit in parallel with at least one second battery unit. A serial configuration is provided by connecting a first accumulator unit in series to at least one further, second accumulator unit.

The battery units are part of the vehicle battery. In a specific embodiment, the vehicle accumulator comprises two accumulator units, namely a first and a second accumulator unit, which are of the same size and are each connected in the same way. In other words, the accumulator units preferably offer the same nominal voltage. The accumulator units are also preferably identical in terms of their capacity, their type and / or their nominal or maximum current.

The vehicle accumulator is configured using a configuration circuit. This can be part of the vehicle accumulator, but can also be provided between the DC voltage converter and the vehicle pre-accumulator. The configuration circuit connects several accumulator units (for example two) of the vehicle accumulator selectively in parallel or in series with one another. The parallel connection results in a total terminal voltage which corresponds to the terminal voltage or nominal voltage of one of the accumulator units. In the case of a serial configuration, the total terminal voltage corresponds to the sum of the separation voltages of the accumulator units. With two accumulator units, this results in a terminal voltage in a serial configuration that is twice as large as the terminal voltage in a parallel configuration. The total terminal voltage can correspond to a voltage that is present at an accumulator connection, via which the configuration circuit or the vehicle accumulator is connected to the DC voltage converter.

If provided, the DC-DC converter is preferably designed as a step-down converter. In other words, the conversion can correspond to a downward conversion. The DC-DC converter can be designed as a unidirectional converter. When represented as a step-down converter, this comprises a switch on one input side and a diode connected in series therewith, the resulting connection point being connected to the output of the converter via an inductance (in particular a dedicated coil). The result is a particularly simple embodiment of the DC-DC converter. This is possible because the configuration of the vehicle battery packs at least part of the adjustment between the clamping voltage and the (rectified) charging voltage, i. H. first DC voltage.

In a further embodiment, the DC-DC converter is provided and is designed bidirectionally. In particular, the DC-DC converter is designed as a synchronous converter. In this case, the DC-DC converter comprises two switches connected in series on the input side, the resulting connection point being connected to an output side of the DC-DC converter via a (dedicated) coil. In this case, the terms first and second side can be used instead of the input and output side, since the resulting converter can work bidirectionally and thus one side can be both input and output side, depending on the application. With a bidirectional DC voltage converter, voltage can be fed back from the traction accumulator to the charging connection.

The AC voltage is preferably converted into the first DC voltage by means of a power factor correction filter. In other words, the rectifier is preferably designed as a power factor correction filter. Other embodiments provide that the rectifier is a controlled rectifier. It can thus be provided that the AC voltage is converted into the first DC voltage by means of a controlled rectifier. Controlled rectifiers are rectifiers in which not only the current direction has an effect on the current flow, but also an (additional) control signal. In particular, the AC voltage is converted into the first DC voltage, with a step-up being carried out at the same time. This function can be used, for example, with power factor correction filters or with Vienna filters. In other words, the rectifier can, as mentioned, be designed as a power factor correction filter and in particular as a Vienna rectifier.

It can further be provided that the first DC voltage is smoothed. For this purpose, an intermediate circuit capacitor can be provided. This is connected downstream of the rectifier and, in one example, can be arranged between the rectifier and the DC converter. The intermediate circuit capacitor is connected in parallel to the two potentials which represent the rectified DC voltage.

In a specific embodiment, the first phase number is one and the second phase number is three. If one is thus recognized as the number of phases, this corresponds to a single-phase AC voltage at the AC connection. If three is recognized as the number of phases, this corresponds to a three-phase AC voltage to the AC connection. With an AC voltage with a (single-phase) effective voltage of 230 V, corresponding to the European public AC network, the rectifier can be used to achieve a first DC voltage of 450 V. Here, in particular, the DC voltage is not only rectified, but also boosted by the rectifier, for example by means of a power factor correction filter as a rectifier. If the number of phases is one, the accumulator is also adapted to an intermediate circuit voltage of 450 V by providing the vehicle accumulator in a parallel configuration. The vehicle battery is preferably provided in two parts, ie comprises two (and preferably not more than two) battery units. These each have a nominal voltage of approximately 400 V or 410 V, for example. With a voltage of 450 V as the first DC voltage, the DC-DC converter can thus charge the traction accumulator, which can have a total clamping voltage of 410 V with a fully charged state. Depending on the state of charge of the traction accumulator, the terminal voltage can be 235 V (or only 220 V) to 410 V (depending on the type of accumulator), whereby the DC-DC converter is designed as a step-down converter and thus, based on a first DC voltage of 450 V, covers the entire voltage range 235 to Can output 410 V as a second DC voltage.

In this case, if the number of phases is three, the second DC voltage (also referred to as an intermediate circuit voltage) can be, for example, 850 V.

Not only the chaining factor of three-phase charging has to be taken into account here, but also the step-up function of the rectifier, which, as mentioned, can be designed as a power factor correction filter. The vehicle battery is preferably in a serial configuration, with the battery being two-part, the battery voltage can be, for example, 470 V to 820 V (corresponding to the double values of the single-phase path or the parallel configuration). Starting from 850 V, the DC-DC converter can thus generate a voltage of 820 V from the first DC voltage (850 V) with a fully charged battery. Furthermore, depending on the state of charge, the battery voltage can vary between 470 V and 820 V, this range being completely covered by the preferably low-setting DC voltage converter, provided that 850 V is set as the first DC voltage, for example.

It can also be provided that the rectifier generates a rectified DC voltage which is at least 5%, 10%, 15% or 20% above the nominal voltage or maximum voltage of the vehicle battery. In particular, the rectified DC voltage is not more than 25, 20, 15 or 10% above the maximum voltage or nominal voltage of the vehicle battery. The maximum voltage can correspond to the voltage of the accumulator, which the latter has with a charge state of 100%. As mentioned, the voltage of the vehicle battery depends on its configuration. The level of the first DC voltage (i.e. the level of the rectifying voltage) depends on the chaining factor and thus on the number of phases.

In particular, it can be provided that the rectifier can be controlled and thus can generate different output voltages (depending on the setting) with the same input voltage. However, it is preferred that the first DC voltage, i. H. the intermediate circuit voltage can only vary by a voltage range (due to variable charge states) that is not greater than 25 volts to 85 volts. As mentioned, the remaining adjustment can be achieved by configuring the vehicle battery and by adjusting the DC / DC converter.

One embodiment provides that the accumulator is formed in two parts (and thus has two accumulator units). In a first process phase, in this embodiment the accumulator is configured serially and a single-phase current (number of phases = 1) is rectified. This is carried out in particular if the terminal voltage of the accumulator units is below a threshold value - which is also referred to as the first-mentioned threshold value - of, for example, 220 V, 230 V or 240 V. The (first mentioned) threshold value can also be 250 V, 300 V or 320 V. In this case, when using a step-up rectifier, such as a Vienna rectifier, a single-phase AC voltage with an effective value of 230 V (peak voltage 325 V) is used to generate a voltage that is suitable for charging, either by directly applying it or by charging it rectified voltage, or by converting the rectified voltage and applying the converted voltage to the accumulator. Provision can be made for the configuration to be changed over to a parallel configuration when a further threshold value is reached (due to the respective terminal voltage of the battery units) as part of a second, subsequent method phase. The further threshold is greater than the first-mentioned threshold. The further threshold value can be, for example, 300 V, 320 V or 350 V or even 370 V. Furthermore, after or with the setting of the parallel configuration, a second one Start process phase. In the second process phase, a single-phase alternating current (number of phases = 1) is preferably rectified. A parallel configuration is preferably provided in the second process phase. A third process phase can be provided in which a three-phase alternating current is rectified (number of phases = 3). In the third process phase, a serial configuration of the accumulator can be provided. The third process phase preferably follows the second process phase. One embodiment provides that the third process phase follows the first process phase (without a second process phase). This embodiment preferably provides that the rectified DC voltage is converted and the converted DC voltage is applied to the accumulator. The third process phase preferably begins when an additional threshold value (due to the respective terminal voltage of the battery units) is exceeded, for example an additional threshold value of 350 V or 370 V or 385 V. The additional threshold value is greater than the further threshold value. The additional threshold is greater than the former threshold.

The vehicle accumulator (short: accumulator) can be charged by applying the rectified DC voltage to the vehicle accumulator. Alternatively, the vehicle accumulator can be charged by the rectified DC voltage from a DC voltage converter ( GW ) is converted and the converted voltage is applied to the vehicle accumulator.

Furthermore, a vehicle electrical system is described that is set up to carry out the method mentioned here. The vehicle electrical system has a control unit. This is connected to the AC connection. The control unit is set up to detect the number of phases at the AC connection. A rectifier of the vehicle electrical system is set up to convert the AC voltage into the first DC voltage. As mentioned, this rectifier, which is used to convert the AC voltage into the first DC voltage, can be a controlled rectifier, in particular a power factor correction filter, such as a Vienna filter. The rectifier is in particular of a multi-phase design, but can also be operated in a single phase (for example if all phases of the rectifier are inactive except for one), depending on the number of phases at the AC connection and possibly according to a desired charging mode with a specific number of phases. The number of phases corresponds in particular to the number of active phases of the rectifier.

The vehicle electrical system can also have a DC voltage converter. This is set up to execute the rectified DC voltage (of the rectifier) into a converted DC voltage. In this variant, the vehicle accumulator is connected to the rectifier via the DC voltage converter. In this case, the rectifier connects the AC connection to the DC converter. Alternatively, the rectifier can be connected to the vehicle accumulator without a converter. In this case, the rectified DC voltage (of the rectifier) is applied to the vehicle battery. The rectifier is set up to generate differently high DC voltages with the same AC voltage.

The configuration is carried out by means of the control unit. For this purpose, the control unit is connected to the configurable vehicle accumulator in a driving manner. In particular, the control unit is connected to a configuration circuit of the vehicle battery (or a configuration circuit upstream of the battery) in a driving manner. The control unit is set up to set the configuration of the vehicle battery. The control unit is designed to configure the vehicle accumulator in accordance with the different configurations when the number of phases is detected. As mentioned, the control unit is preferably designed to provide the vehicle accumulator in a parallel configuration for a first phase number that is smaller than a second phase number, and is further configured to configure the vehicle accumulator in a serial configuration for the detected second (larger) phase number. The control unit can be set up to initially provide the vehicle accumulator in a parallel configuration for a first phase number that is smaller than a second phase number, and is also set up to then configure the vehicle accumulator in a serial configuration for the detected second (larger) number of phases. In a further embodiment, the control unit can be set up to initially provide a serial configuration for a first number of phases (approximately 1). The control unit can be set up, after which a parallel configuration can be controlled. The parallel configuration can be linked to the same or a higher number of phases (approximately 3). In particular, the control unit can be set up to control a parallel configuration for the same phase number after the serial configuration for the first phase number, and then to control a serial configuration for a second (compared to the first) higher phase number.

The control unit is set up to set a parallel configuration (this battery) as the first configuration of the vehicle battery by means of an adjustable configuration circuit for a first phase number that is smaller than the second phase number. The Configuration circuit can be part of the vehicle battery or can be connected upstream of this. The control unit is further configured to use the adjustable configuration circuit to set a serial configuration of the vehicle accumulator as the second configuration if the second number of phases is detected. As mentioned, the configuration circuit can also be connected upstream of the vehicle accumulator and thus connect the vehicle accumulator to the DC voltage converter. Ultimately, the configuration circuit is connected upstream of the battery units of the vehicle battery. The configuration circuit can (as part of the vehicle battery or upstream of this) connect the battery units to the DC / DC converter. The connection between the accumulator units and the configuration circuit makes it possible to provide different configurations of the accumulator units by means of the configuration circuit. The controller can be connected upstream of the rectifier and can be set up to control the number of (active) phases. The controller can therefore be set up to set the number of phases. The detection of the number of phases then corresponds, for example, to the forwarding or use of a signal which reproduces the (to be controlled) number of phases.

The vehicle accumulator can have a plurality of accumulator units. These are connected to the adjustable configuration circuit. Together with the configuration circuit, the accumulator units are set up to be connected to one another either in parallel or in series. The vehicle accumulator is preferably equipped with two (and not with more than two) accumulator units. These can be connected to each other in series or in parallel using the configuration circuit. The result is a single or multiple terminal voltage (twice the terminal voltage for two accumulator units) in the direction of the DC-DC converter, depending on the configuration. A voltage of an accumulator unit is referred to here as a simple voltage; The double voltage results when two of the accumulator units are connected in series, in particular if the accumulator has two (and not more than two) accumulator units.

The accumulator units are also connected to the DC / DC converter via the configuration circuit, if this is present. The accumulator units can also be connected (converter-free) to the rectifier via the configuration circuit. As mentioned, the configuration circuit can be part of the vehicle battery or can be provided between the DC voltage converter or the rectifier on the one hand and the vehicle battery on the other.

The vehicle battery is in particular a high-voltage battery. The vehicle battery can be configured as a lithium battery. The vehicle accumulator is in particular a traction accumulator.

The vehicle electrical system can in particular comprise an intermediate circuit capacitor which is connected downstream of the rectifier, is connected upstream of the DC voltage converter (if present) or is connected between the rectifier and the DC voltage converter. The intermediate circuit capacitor is connected as a smoothing capacitor and is therefore connected in parallel to the relevant DC voltage potentials. The intermediate circuit capacitor can be connected (directly) upstream of the configuration circuit, in particular if the rectifier is connected to the accumulator or to the configuration circuit without transformers.

The control unit can also be connected to the DC-DC converter (if present) and / or to the rectifier. This is particularly the case if the rectifier is controllable. The control unit is set up to selectively deactivate and activate the rectifier. The control unit can also be set up to selectively deactivate and activate the DC voltage converter. In particular, the control unit is set up to set an operating parameter of the converter (if present) and / or the rectifier. The operating variables here are the voltage, in particular the first or the second voltage, and the current or the power via the rectifier or the converter. In addition, the operating variable for the DC-DC converter can correspond to a transmission ratio (ratio of the voltages on both sides of the converter). Furthermore, the operating variable can correspond to a pulse duty factor in the rectifier and / or the DC-DC converter. The number of active phases of the rectifier can also be considered as the operating variable. The control unit is set up not only to activate or deactivate the rectifier (and possibly the DC-DC converter), but also to adjust the adjustments based on the (level of the chained) AC voltage at the AC voltage connection.

The vehicle electrical system can also have an AC voltage connection, which is connected via the rectifier to the DC voltage converter (if present) or to the accumulator or the configuration circuit (in particular in embodiments without a DC voltage converter).

In particular, a charging circuit can be provided as part of the vehicle electrical system comprises an AC voltage connection, a rectifier, a DC voltage converter and an accumulator connection. These can be configured like the components of the same name shown here. In addition, the charging circuit can have an intermediate circuit capacitor. The charging circuit may further include a control unit as described herein. The AC voltage connection of the charging circuit is connected to the DC voltage converter via the rectifier. The DC-DC converter connects the rectifier to the battery connection. The accumulator connection is set up to be connected to the vehicle accumulator. However, the vehicle battery is not part of the charging circuit.

The 1 serves to provide an overview of embodiments of the vehicle electrical system described here.

The 1 shows an AC voltage source WQ, for example in the form of a stationary supply network. As shown, the AC voltage source can be single-phase or three-phase. These two options are shown one above the other as symbols and are to be regarded as options for one and the same device. The symbolically represented switch shows that a selection can exist, and in particular that an adjustment device can be provided which determines the number of phases (ie the number of active phases). This device can be part of the vehicle electrical system or the charging circuit LS, corresponding embodiments not being shown. Furthermore, the selection option shown (single or multi-phase) is intended to represent embodiments in which a rectifier GR is constructed in multiple phases and is set up to determine the number of active phases. Such a rectifier is set up to actively operate all (rectifier) phases in a first state (approximately 3) and to operate only a part of the (rectifier) phases actively in a second state (approximately only one). The rectifier GR has a multi-phase structure.

The electrical system BN is connected to the stationary AC voltage source WQ via the AC voltage connection WA. The electrical system BN includes a rectifier GR (preferably constructed in multiple phases), via which the AC voltage connection WA is connected to an intermediate circuit capacitor ZK. Via the intermediate circuit capacitor ZK is the rectifier GR with the optional DC-DC converter GW connected. The DC-DC converter GW is connected to a vehicle battery AK via the battery connection BA. The rectifier is optional and therefore shown in dashed lines. The 1 thus also serves to represent embodiments in which the rectifier GR or the intermediate circuit capacitor ZK is connected to the battery AK without a converter. Here are the rectifier GR (and especially the intermediate circuit capacitor ZK ) directly with the accumulator or a configuration circuit described below KO connected.

It is an adjustable configuration circuit KO provided, by means of which the configuration (serial or parallel) of the two accumulator units AE1.2 can be adjusted. In the example shown, the configuration circuit is part of the vehicle battery AK . In other embodiments, however, this is not the case, but rather the configuration circuit is connected upstream of the battery units of the vehicle battery.

It can be seen that between the configuration circuit KO and the accumulator units AE1.2 Connections exist, by means of which the configuration (ie interconnection) of the two accumulator units can be set by setting the configuration circuit AE1.2 can be adjusted. In the example shown, this corresponds to the possibility of the two accumulator units AE1.2 to be connected in series or in parallel.

It can be provided that, as shown by the dashed arrow, the control unit C has a number of phases at the AC voltage connection WA detected. This affects the number of active phases. If this number is one, for example, then the control device C, the configuration circuit, is formed KO to be controlled such that the accumulator units connected to this circuit AE1.2 are connected in parallel. The result is a simple voltage at the accumulator connection BA or at the side of the direct voltage converter, which is the accumulator AK is facing. The voltage that is present at one of the accumulator units is referred to as simple voltage. For this purpose, the control unit C controls the configuration circuit KO connected, as shown by the dashed arrow.

One possibility is that the number of phases is set by means of the control device C. For this purpose, the control unit C is connected to the AC voltage connection or to an adjusting device in a driving manner, as shown by the dotted line arrow (the adjusting device is not specifically shown). Such an adjustment device has the purpose of the symbolically represented switch and selects the number of phases. In a simple case there are three phases, but in a first state (which can be defined by the control unit) only one phase (and the neutral conductor) with the AC voltage connection WA or the rectifier GR connected. In a further state it can be provided that the setting device with all three phases with the AC voltage connection WA or the rectifier GR connects.

It is also conceivable to control the controllable rectifier in such a way that in the first state not all and in particular only one phase of the rectifier is active, while the others do not carry any current. In a second state it can be provided that the controllable rectifier GR all three phases of the rectifier are set in the active state and thus the three phases of the AC connection are also rectified via three phases of the rectifier. In a corresponding embodiment, the control unit would control the rectifier GR also connected to the number of active phases of the rectifier GR head for. This is shown with the dash-dotted arrow. The detection of the number of phases then corresponds to the display or branching of a signal which determines the number of active phases.

As mentioned, a setting device can thus determine the number of phases, or the rectifier GR can determine (and thus set) the number of phases by appropriate control by means of the control unit C. In the latter case, the control unit C is also set up to detect the number of phases by passing on a corresponding control signal.

The circuit shown is preferably used for alternating current sources with an effective nominal voltage of 230 V, which can in particular be single or three-phase. The configuration of the vehicle accumulator is set as a function of this number of phases or the number of phases of the AC voltage source that are actually also used.

The term “configurable vehicle accumulator” refers to vehicle accumulators that have cell groups that can be connected either in parallel or in series and thus configured. This can be provided by the vehicle battery AK (Separable) accumulator units AE1, 2nd or in that the vehicle accumulator also has a configuration circuit in addition to the accumulator units KO over which the accumulator units AE1, 2nd can be interconnected according to the configuration (in an adjustable manner). As mentioned, however, the configuration circuit is not necessarily part of the vehicle battery. A charging circuit LS can therefore not have the vehicle accumulator, but the configuration circuit. In this case there is an interface between the configuration circuit and the accumulator units (outside the charging circuit LS ) as part of the charging circuit LS can be viewed.

In the example shown, the charging circuit comprises LS the AC voltage connection WA , the rectifier GR , the intermediate circuit capacitor ZK , the optional DC-DC converter GW , the accumulator connection BA and the configuration circuit KO . The accumulator units connected to it AE1, 2nd are not part of the charging circuit in this case. Alternatively, the charging circuit LS the AC voltage connection WA , the rectifier GR , the intermediate circuit capacitor ZK , the optional DC-DC converter GW and the accumulator connection BA , wherein the charging circuit then comprises an interface via which a configuration signal can be emitted, which reflects the configuration of the accumulator to be set. In this case, the configuration circuit is not part of the charging circuit, the charging circuit being set up by means of the interface to emit the configuration signal. The accumulator or the configuration circuit (within the vehicle electrical system, but outside the charging circuit) can be controlled by means of the configuration signal.

Claims (10)

Method for loading a configurable vehicle accumulator (AK) with the steps: Detecting a phase number of an AC voltage at an AC connection (WA); Converting the AC voltage into a rectified DC voltage by means of a rectifier (GR); and Charging the vehicle battery (AK) by means of the rectified DC voltage, wherein in the case of a first phase number, the vehicle accumulator (AK) is configured in accordance with a first configuration and in the case of a second phase number which is different from the first, the vehicle accumulator (AK) is configured in accordance with a second, different configuration before the conversion and charging is carried out. Procedure according to Claim 1 , a parallel configuration of the vehicle accumulator being provided when the first phase number, which is less than the second phase number, than the first configuration of the vehicle accumulator (AK), and wherein a serial configuration of the vehicle accumulator (AK) when the second phase number is detected is provided. Method according to one of the preceding claims, wherein the vehicle accumulator (AK) is configured by means of a configuration circuit (KO), which is adjustable a plurality of accumulator units (AE1, 2) of the vehicle accumulator (AK) optionally connected in parallel or in series. Method according to one of the preceding claims, wherein the vehicle accumulator (AK) is charged by applying the rectified DC voltage to the vehicle accumulator (AK). Procedure according to one of the Claims 1 - 3rd , wherein the vehicle accumulator (AK) is charged by converting the rectified DC voltage by a DC voltage converter (GW) and applying the converted voltage to the vehicle accumulator (AK). Method according to one of the preceding claims, wherein the AC voltage is converted into the first DC voltage by means of a power factor correction filter. Vehicle electrical system (BN) set up to carry out the method according to one of the preceding claims, wherein the vehicle electrical system (BN) comprises: a control unit (C), which is connected to the AC connection (WA) and is configured to detect the number of phases at the AC connection (WA); a rectifier (GR) configured to convert the AC voltage to the rectified DC voltage; and the vehicle accumulator (BN) connected to the rectifier (GR); wherein the control unit (C) is connected to the vehicle accumulator (AK) in a driving manner and is set up to set the configuration of the vehicle accumulator (AK), the control unit (C) being further configured to differentiate the vehicle accumulator (AK) in accordance with the different at different detected phase numbers Configure configuration. Vehicle electrical system after Claim 7 , wherein the control unit (C) is set up to set and set up a parallel configuration by means of an adjustable configuration circuit (KO) of the vehicle accumulator (AK) at a first phase number, which is less than the second phase number, than the first configuration of the vehicle accumulator (AK) is to set a serial configuration of the vehicle battery (AK) as the second configuration by means of the adjustable configuration circuit (KO) if the second number of phases is detected. Vehicle electrical system after Claim 8 , The vehicle accumulator (AK) has a plurality of accumulator units (AE1, 2) which are connected to the adjustable configuration circuit (KO) and, together with the configuration circuit (KO), are set up to be connected to one another either in parallel or in series. Vehicle electrical system after Claim 7 , 8th or 9 , wherein the vehicle accumulator (BN) is connected directly or via the direct voltage converter (GW) to the rectifier (GR).

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