DE102019204000A1 - Charging device for charging a respective energy store of several motor vehicles - Google Patents

Abstract

Charging device for charging a respective energy store (2) of several motor vehicles (3, 4, 5) with energy provided by a supply network (6), comprising a first charging connection (7), wherein the charging device (1) is configured to connect to the first Charging connection (7) to provide a first DC voltage for charging a first motor vehicle (3), the charging device (1) comprising at least one DC voltage converter (8, 9) which is set up to convert the first DC voltage to a respective further DC voltage, the Charging device (1) is set up to provide the respective further DC voltage at a respective further charging connection (10, 11) for a respective further motor vehicle (4, 5).

Description

The invention relates to a charging device for charging a respective energy store of several motor vehicles with energy provided by a supply network, comprising a first charging connection, wherein the charging device is set up to provide a first DC voltage for charging a first motor vehicle.

Today's electric vehicles typically have a combo charging socket which, on the one hand, enables direct current charging, for example up to a power of 150 kW, and, on the other hand, enables alternating current to be charged, for example up to a charging power of 22 kW. Currently, the majority of electric vehicles are charged with AC voltage when they are charged at the user's place of residence, for example in a garage. However, the need to enable both direct current charging and alternating current charging results in increased space consumption in the motor vehicle and higher costs.

For future generations of electric vehicles, it is therefore to be expected that, in principle, direct current charging of the motor vehicle should take place. If, in this case, charging is to take place on a private power connection, a user must use a corresponding converter, which can be installed, for example, as a DC wallbox in a garage or at another location in the vehicle. This means that charging circuits on the vehicle side can largely be dispensed with.

If several electric vehicles are to be charged in parallel with direct current at one location, for example in a user's garage, this can be done by providing a corresponding direct current converter or a corresponding DC wallbox for each of the vehicles. Since the charging power is still limited by the maximum power of the house connection, despite the use of two DC wallboxes, only the same power can still be used, so that the charging power provided in each case has to be reduced. The purchase of several separate DC wallboxes also results in relatively high costs, which in particular prevents the widespread use of corresponding charging architectures among private users.

From the pamphlet DE 10 2017 108 579 A1 a method for operating a charging station for charging several electric vehicles is known, in which first a direct voltage is provided on a direct voltage bus which supplies several charging connections. The DC / DC converters assigned to the individual charging connections provide charging currents for various vehicles as required. If a large number of charging connections are to be supplied, reduced circuit complexity can be achieved by using the DC voltage bus. In particular in private use, however, the problem with such a charging station is that an additional common voltage converter is required due to the use of the common DC voltage bus. If, for example, only one charging connection is to be supplied, this can lead to a higher circuit complexity and lower efficiency compared to conventional DC wall boxes. In particular for private use, however, it would be advantageous to be able to provide a charging device that can be expanded with additional charging connections as required. However, since a relatively large number of users only need one charging connection or at least only a few charging connections, the charging station explained is only suitable to a limited extent for this purpose.

The invention is therefore based on the object of specifying a charging device in which the circuit complexity can be reduced with a relatively small number of charging connections.

The object is achieved by a charging device of the type mentioned at the beginning, the charging device comprising at least one DC voltage converter which is set up to convert the first DC voltage to a respective further DC voltage, the charging device being set up to apply the respective further DC voltage to a respective further Provide charging connection for a respective further motor vehicle.

According to the invention, it is therefore proposed to use the DC voltage that is already required for the first charging connection in order to use this to supply at least one further charging connection via a respective additional DC voltage converter. With the same number of charging connections, the document cited at the beginning DE 10 2017 108 579 A1 a DC / DC converter is required less, which, in particular with a small number of charging connections, leads to less circuit complexity. The charging device according to the invention can also be provided with particular advantage by a modular system, wherein a first module provides the first DC voltage and, if necessary, at least one additional module with a respective DC voltage converter can be added to provide a respective further charging connection.

The advantages are achieved in that it was recognized that in the case of the invention Charging device the first DC voltage, which is fed to the individual DC voltage converters, is typically varied when a first motor vehicle is to be charged, but this can be compensated for without problems by a corresponding control of the DC voltage converter. The dedicated provision of a fixed intermediate voltage can thus be dispensed with, which can lead to cost savings and higher efficiencies.

If the first charging connection is not used, it can optionally be separated from the first direct voltage and the first direct voltage can be set to a fixed value, for example. If both the first charging connection and at least one further charging connection are used, the DC-DC converter of the further charging connection can be activated in such a way that its output voltage is independent of the input voltage. This can be achieved, for example, in that the first direct voltage or information about the first direct voltage, for example control parameters used to generate the first direct voltage in a controlled rectifier, are known to a control device controlling the direct voltage converter, whereby the variation of the first direct voltage by a corresponding active control can be compensated. However, it is also known to regulate DC voltage converters to a predetermined output voltage, whereby variations in the input voltage, that is to say in the first DC voltage, are automatically compensated.

The first direct voltage can be the output voltage of an, in particular active, rectifier. The rectifier can be a bridge rectifier which is fed by three-phase current either directly or after galvanic separation. As will be explained in more detail later, however, it can be advantageous to feed the rectifier in single phase and previously to optionally use a current conversion to convert a three-phase supply voltage to a single-phase input voltage of the rectifier.

The first charging connection can be arranged on a main housing, wherein the respective further charging connection is arranged together with the respective DC voltage converter in a respective additional housing which is embodied separately from the main housing. In particular, several charging connections can be provided by using several additional housings, each with a charging connection and an assigned DC voltage converter. The rectifier and / or components for galvanic isolation can be arranged in the main housing. By using separately designed additional housings to provide the further charging connections, the modular construction of the charging device explained at the beginning can be achieved particularly easily, with which a charging device can be used as required that exclusively comprises the main housing and thus only the first charging connection or a charging device according to the invention in which several charging connections can be used by adding at least one additional housing to the main housing.

The additional housing or at least one of the additional housings can have an input connection for supplying the first DC voltage and an output connection for providing the first DC voltage to another of the additional housings. In this way, the charging device according to the invention can be supplemented particularly easily by adding further additional housings and thus further charging connections. Compared to a star-shaped supply of the first DC voltage to all additional housings, a simpler expansion and less wiring effort is achieved. The voltage connections from the input and output connection can be directly connected in a conductive manner. Particularly preferably, a disconnector can be used which can disconnect at least the line carrying the first direct voltage from the input connection to the output connection. For example, it can be achieved by means of appropriate mechanics or electronics that the output connection is only subjected to the first direct voltage if a further additional housing or a connecting cable is also connected to it.

As will be explained in greater detail later, it can be useful if control or communication devices in the additional housings can communicate with a control or communication device on the main housing side. To make this possible, the input and / or output connection can additionally couple at least one communication line. Alternatively, it would be possible, for example, to use wireless communication.

In addition to the first charging connection, the main housing preferably has an output connection for connection to the input connection of one of the additional housings at which the first direct voltage is provided. As explained above, the first DC voltage can be separated from this output connection by a disconnector if no additional housing or connection cable is connected. The use of an output connection on the main housing makes it possible to connect additional housings without blocking the first charging connection or without additional adapters being required.

The additional housing or at least one of the additional housings can additionally comprise a communication device for communication with a communication device of the main housing and / or with a communication device external to the charging device and / or a disconnection device for separating the respective further DC voltage from the respective further charging connection. The communication device can be set up to control the respective DC / DC converter and / or the respective disconnection device. The communication devices can, as explained above, communicate in a wired or wireless manner, for example via known cellular radio standards, the W-LAN standard, Bluetooth® or the like.

A mobile phone, a tablet, a PC or the like, for example, can be used as the communication device external to the charging device. A corresponding app or application can be used to control the charging device or communication with the individual communication devices, or at least one of the communication devices can implement a web interface that can be accessed via conventional network protocols, for example with a browser. The charging device-side communication device can be used to authenticate a user or a charging device-external communication device in order to prevent unauthorized influencing of the charging process.

The communication between the communication devices of the charging device can in particular serve to distribute a power provided from the supply network automatically or as a function of user specifications or the like to different motor vehicles connected to different charging connections. In addition or as an alternative, it can serve to inform the communication or control devices of the individual additional housings when the first DC voltage changes, for example due to a specific charging request from the first motor vehicle. This can improve the regulation or control of the further DC voltage or DC voltages, particularly in the case of rapid and / or strong changes.

At least one communication device of the charging device can be set up to communicate with the or one, in particular portable, charging device-external communication device of a user. This can be done as explained above for the purposes explained above.

The communication with a user's communication device external to the charging device can in particular serve to distribute an available charging power freely or in accordance with user specifications to the various charging connections. For example, a user may want one of the motor vehicles to be charged particularly quickly and thus with a large part of the available charging power.

The communication device external to the charging device preferably does not communicate directly with communication devices in the additional housing, but rather via a communication device arranged in the main housing. This is useful, for example, when a total charging power is to be distributed, since in this case the distribution is carried out by a single communication device of the charging device and this controls the further communication devices of the additional housing accordingly. Alternatively, it would be possible, for example, for the communication device external to the charging device to communicate directly with the individual communication devices of the additional housing. In this case, coordination of the control of the individual DC voltage converters, which may be required under certain circumstances, can be carried out, for example, by an application or app that is executed on the user's communication device external to the charging device.

The charging device can be configured to transfer power from the charging connection to the further charging connection and / or vice versa and / or between at least two of the further charging connections and / or to transfer power from the further charging connection or the further charging connection into the supply network. In other words, bidirectional energy transfer can be possible for at least parts of the charging connections. This can be used, for example, to use the energy store on the motor vehicle side as a buffer store, for example to compensate for load peaks or periods of particularly high energy generation, for example by solar cells or wind power plants. An energy transfer out of the energy store on the vehicle side can also be advantageous, for example, in order to set a charge state of the energy store that is particularly advantageous for a long service life of the energy store during longer idle times. A power or energy transfer between the various charging connections can be advantageous, for example, in order to charge one of the motor vehicles particularly quickly if it is accepted that the energy store of one of the other motor vehicles is discharged or the like.

DC voltage converters or controllable rectifiers with reversible power flow direction are known in principle in the prior art and should therefore not be explained in detail. The charging device can be connected to the Be coupled to the supply network. If it is possible to transfer power or energy from the charging connections into the supply network, it is useful to use a bidirectional meter.

The charging device can be set up to provide different charging capacities at the charging connection and the further charging connection and / or at at least two of the further charging connections as a function of a user input on an input device of the charging device and / or a message received from the or a charging device-external communication device. This makes it possible, for example, to distribute an available charging power to different motor vehicles via the input device or the communication device external to the charging device, as explained above. In addition or as an alternative, depending on the user input or the received message, a power flow direction can also be selected, for example it can be set that power is to be transferred from the charging connection to the further connection or vice versa or between at least two of the further charging connections or that power is to be transferred from the further charging connection into the supply network.

If the first DC voltage is provided via a controlled rectifier, as explained above, this can be controlled in such a way that it converts all of the energy or power transferred into or from the supply network. Appropriate control of the DC voltage converters specifies which proportion of this power is provided at the individual additional charging connections. The remaining power is provided at the first charging connection.

The first direct voltage can, in particular immediately before the rectifier or a rectifier providing the first direct voltage, be galvanically isolated from the supply network by an isolating component. In particular, no further galvanic separation can take place between the provision of the first direct voltage and the individual charging connections. This means that galvanic isolation can be achieved for all charging connections with little technical effort. Galvanic isolation can be achieved, for example, using a transformer. For example, if the supply network is three-phase, galvanic isolation can be provided for each of the three phases. However, as explained below, the three-phase alternating voltage is advantageously first converted to a single-phase alternating voltage, as a result of which galvanic separation is only required for one phase, whereby the circuit complexity can be further reduced.

A converter circuit can be connected between the isolating component and the supply network, which converts a particularly three-phase voltage of the supply network to an intermediate DC voltage and converts this to a single-phase AC voltage. As a result, as explained above, only one phase has to be galvanically isolated. In addition, the single-phase alternating voltage can be essentially insensitive to network disturbances, so that the particularly controlled rectifier that provides the first direct voltage only needs to convert a well-defined alternating voltage.

• 1 eine Prinzipdarstellung eines Ausführungsbeispiels der erfindungsgemäßen Ladeeinrichtung,
• 2 eine Detailansicht der Funktionsblöcke der in 1 gezeigten Ladevorrichtung, und
• 3 die Schaltung eines weiteren Ausführungsbeispiels einer erfindungsgemäßen Ladeeinrichtung.

The following exemplary embodiments and the associated drawings show further advantages and details. Here show schematically:

• 1 a schematic diagram of an embodiment of the charging device according to the invention,
• 2 a detailed view of the function blocks of the in 1 shown loading device, and
• 3 the circuit of a further embodiment of a charging device according to the invention.

1 shows a loading device 1 for charging a respective energy store 2 of several motor vehicles 3 , 4th , 5 . The energy storage 2 can in particular supply a drive motor of an electric motor vehicle or a hybrid vehicle, but it can also be any other energy storage device.

The loading device 1 is through a three-phase supply network 6th and provides a respective DC voltage at the charging connections 7th , 10 , 11 ready to store the energy 2 of motor vehicles 3 , 4th , 5 to load. Here, the charging device preferably comprises, as in FIG 1 is shown a main body 18th and several additional housings supplied by this with direct voltage 26th , 27 . Alternatively, it would of course also be possible to use all charging connections 7th , 10 , 11 to be arranged on a single housing.

The provision of DC voltage to the individual charging connections 7th , 10 , 11 will be referred to below with reference to 2 explained in detail.

To a first DC voltage for charging the first motor vehicle 3 is provided by a controlled rectifier 23 a first DC voltage at the charging connection 7th provided. This first DC voltage is also used by the DC voltage converters 8th , 9 provided to a respective further DC voltage at the charging connections 10 , 11 to the other vehicles 4th , 5 to provide.

The supply network 6th provides an alternating voltage on three phases 12 , 13 , 14th ready. In addition, the supply network provides a reference potential 15th and a protective conductor 16 ready. Energy or power taken from the supply network or fed back energy or power is measured by a bidirectional electricity meter 17th detected. To the entire charging device from the supply network 6th to be able to separate is in the main housing 18th a disconnection device on the supply network side 19th intended.

The supplied three-phase alternating voltage is first fed to a controlled bridge rectifier 20th and the resulting DC voltage is passed through the inverter 21st reversed again to single-phase a separating component 22nd , for example a transformer to be supplied. The bridge rectifier 20th and the inverter 21st thus together form a converter circuit that provides a three-phase voltage of the supply network 6th converted to a single-phase AC voltage. After the galvanic separation takes place via a controlled rectifier 23 the provision of the first DC voltage. The first DC voltage is switched off via a cut-off device 24 the first charging port 7th fed to the energy store 2 of the first motor vehicle 3 to load. The first shutdown device 24 allows the charging port 7th separated from the first DC voltage when this is not used.

The first DC voltage and thus in particular the controlled rectifier 23 are through a communication device 36 in the main body 18th controlled. This also controls the cut-off device 24 . Via a control device 35 or a communication device external to the charging device 34 a user, for example a smartphone with a corresponding app, can operate these devices and thus charge the first motor vehicle 3 being controlled. The main body 18th thus comprises all components that are required to provide a complete charging device for charging a single motor vehicle. If a user only wants to charge one motor vehicle in his garage or at his parking space, it is sufficient to only use the main housing there 18th to install.

The advantage of the charging device explained is that further charging connections are required with very little technical effort 10 , 11 for other motor vehicles 4th , 5 can be provided, for example if a user wants to install a charging device for several motor vehicles or would like to expand an existing charging device in order to be able to charge another motor vehicle in parallel. For this purpose, the first DC voltage is also applied to an output connection 25th of the main body 18th for the additional housing 26th , 27 provided. Alternatively, it would be possible, for example, to provide this via an additional adapter on the charging connection 7th to enable the first DC voltage to both a charging cable led to the motor vehicle and at least one of the additional housings 26th , 27 feeds.

This DC voltage is used in the additional housing 26th via the input connector 28 fed and to the output port 30th looped through. This also makes the first DC voltage for the input connection 29 of the additional housing 27 provided and there again on the output connection 31 looped through in order to be able to connect additional additional housings as an option. Optional could be the connection between input port 28 , 29 and output connector 30th , 31 or between the rectifier 23 and the output port 25th For example, it can be separated by a switch in order to apply voltage to the respective output connection 25th , 30th , 31 to prevent if no components are connected to the respective output connection.

In addition to the DC / DC converter 8th , 9 include the additional housing 26th , 27 one shutdown device each 32 , 33 , the functional of the defeat device 24 corresponds. In addition, there are respective communication facilities 37 , 38 provided that the respective DC voltage converter 8th , 9 as well as the defeat devices 32 , 33 Taxes.

An alternative embodiment with a relatively simple circuit structure is shown in FIG 3 shown. The supply network feeds here 6th directly a rectifier 20th . The inverter 21st , the separating component 22nd for galvanic isolation and the controlled rectifier 23 can also be viewed together as a bidirectional, galvanically isolating DC-DC converter, as the result is a galvanically isolating DC-DC conversion. The first direct voltage provided by these components is, on the one hand, fed directly to the first charging connection 7th and on the other hand via additional DC voltage converters 8th , 9 the other charging connections 10 , 11 .

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102017108579 A1 [0005, 0008]

Claims (10)

Charging device for charging a respective energy store (2) of several motor vehicles (3, 4, 5) with energy provided by a supply network (6), comprising a first charging connection (7), wherein the charging device (1) is configured to connect to the first Charging connection (7) to provide a first DC voltage for charging a first motor vehicle (3), characterized in that the charging device (1) comprises at least one DC voltage converter (8, 9) which is set up to convert the first DC voltage to a respective further DC voltage , wherein the charging device (1) is set up to provide the respective further direct voltage at a respective further charging connection (10, 11) for a respective further motor vehicle (4, 5). Loading device after Claim 1 , characterized in that the first direct voltage is the output voltage of an, in particular active, rectifier (23). Loading device after Claim 1 or 2 , characterized in that the first charging connection (7) is arranged on a main housing (18), the respective further charging connection (10, 11) together with the respective DC voltage converter (8, 9) in a respective separate from the main housing (18) formed additional housing (26, 27) is arranged. Loading device after Claim 3 , characterized in that the additional housing (26, 27) or at least one of the additional housings (26, 27) has an input connection (28, 29) for supplying the first DC voltage and an output connection (30, 31) for providing the first DC voltage to another the additional housing (26, 27). Loading device after Claim 3 or 4th , characterized in that the additional housing (26, 27) or at least one of the additional housings (26, 27) additionally has a communication device (37, 38) for communication with a communication device (36) of the main housing (18) and / or a communication device external to the charging device ( 34) and / or a disconnection device (32, 33) for separating the respective further direct voltage from the respective further charging connection (10, 11). Charging device according to one of the preceding claims, characterized in that at least one communication device (36, 37, 38) of the charging device (1) is set up to communicate with the or one, in particular portable, charging device-external communication device (34) of a user. Charging device according to one of the preceding claims, characterized in that it is set up to supply power from the charging connection (7) to the further charging connection (10, 11) and / or vice versa and / or between at least two of the further charging connections (10, 11) to transfer and / or to transfer power from the further charging connection (7, 10, 11) into the supply network (6). Charging device according to one of the preceding claims, characterized in that it is set up to provide different charging capacities at the charging device (11) and / or a message received from the or a charging device-external communication device (34) as a function of a user input on an input device (35) Charging connection (7) and the further charging connection (10, 11) and / or at least two of the further charging connections (10, 11). Charging device according to one of the preceding claims, characterized in that the first direct voltage, in particular immediately before the rectifier (23) providing the first direct voltage, is galvanically isolated from the supply network (6) by an isolating component (22). Loading device after Claim 9 , characterized in that a converter circuit is connected between the isolating component (22) and the supply network (6), which converts one, in particular three-phase, voltage of the supply network (6) to an intermediate DC voltage and converts this to a single-phase AC voltage.

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