DE102018207183A1 - Device for charging an energy store of an electric vehicle - Google Patents

Abstract

The present invention relates to an extension of an existing vehicle infrastructure, in particular a power converter and an electric motor for power transmission between a traction battery of an electric vehicle and an external DC voltage source connected to a charging port. For this purpose, an additional control module can be arranged between an output of the power converter and a phase connection of the electrical machine, which extends the functionality of the existing circuit topology and the possibility of boosting or stepping down a DC voltage.

Description

The present invention relates to a device for charging an energy store, in particular an energy store of an electric vehicle.

State of the art

Wholly or at least partially electrically powered vehicles are increasingly gaining in importance. With the steadily growing number of electric vehicles, a reliable and modern charging infrastructure is becoming indispensable. While charging stations with a relatively low charging power are generally sufficient for city vehicles, fast charging stations are also desirable, especially for long-distance journeys, which can charge the battery of an electric vehicle with a large charging power in a relatively short time. In this case, the charging of the battery of the electric vehicle is carried out, in particular in rapid charging processes usually by means of direct current.

Today's fast charging stations use, for example, AC / DC converters, such as those from the WO 2012/038222 A2 are known.

Disclosure of the invention

The present invention provides a device for charging an electrical energy store of an electric vehicle with the features of patent claim 1.

Advantages of the invention

With the device according to the invention for charging an energy store of an electric vehicle, it is possible to charge the traction battery of the electric vehicle from a DC voltage source, without the need for an additional DC-DC converter is required. Rather, to adapt the voltage level of the DC voltage for charging the traction battery existing in an electric vehicle structure of the drive components, in particular the voltage converter and the electric machine can be used for the conversion of the DC voltage. As an electric vehicle can be understood for the present invention, any electric vehicle. In particular, the term electric vehicles means both fully or at least partially electrically powered passenger cars, but also trucks, buses, any industrial electric vehicles, etc. In addition, the present invention - as far as appropriate - be used for any applications with an electrical energy storage

In this way, it is possible to adjust the voltage level of the DC voltage provided by a DC voltage source for charging the traction battery of the electric vehicle. In particular, the DC voltage provided by a charging station can thereby be increased or decreased. In this way, a flexible connection between charging station and electric vehicle for charging the traction battery is possible. Furthermore, it is possible to charge the traction battery of an electric vehicle even if the voltage level of the charging station and the voltage level of the traction battery do not match. For example, from the charging station, a high electrical voltage can be provided to keep the losses in the energy transfer from a power supply station to the charging station and from the charging station to the electric vehicle low. Alternatively, it is also possible to charge electric vehicles with an internal high electrical voltage level to charging stations, which may optionally provide only a DC voltage with a lower voltage level.

In addition, the device according to the invention for charging an energy store also allows bidirectional transmission and conversion of the DC voltage. In this way it is also possible, for example, to deliver electrical energy from the internal traction battery of an electric vehicle to an externally connected network or a consumer. Again, the amount of DC voltage, which is provided externally, can be variably adjusted.

Preferred developments are the subject of the respective subclaims.

According to one embodiment, the switching device of the control module is configured either to electrically connect the second terminal of the control device to the fourth terminal of the control device or electrically connect the node of the control module to the fourth terminal of the control device connect to. In a further switching state, the switching device can alternatively electrically connect the second connection, the fourth connection and the node of the control device to one another.

This makes it possible by selectively controlling the switching device of the control module to influence and adjust the current flow between the traction battery of the electric vehicle, the DC voltage source at the charging port of the electric vehicle, the power converter and the electric machine of the electric vehicle. In this way, in particular between switching states for the active control of the electric machine in a motor or generator operation (recuperation) while driving, charging the electrical energy storage in the electric vehicle directly from a DC voltage source at the charging port of the electric vehicle or an energy transfer between the DC voltage source at the charging port and the energy storage in the electric vehicle to be changed with simultaneous conversion of the voltage level.

According to one embodiment, the switching device of the control module comprises at least one semiconductor switch. For example, the semiconductor switches may be MOSFET or bipolar transistors with an isolated gate. In addition, however, other semiconductor switches or possibly mechanical switches are also possible in principle. According to one embodiment, the switching device of the control module comprises a first switch, which is arranged between the second terminal and the fourth terminal of the control device of the control module. Furthermore, the switching device of the control module may comprise a second switch, which is arranged between the node and the fourth terminal of the control device. In this way, a flexible configuration of the switching states for the respective operating mode is possible.

According to an alternative embodiment, the switching device of the control module comprises a switch, which is arranged electrically between the second terminal of the control module and the node in the control module. In this case, furthermore, the node may be electrically coupled to the fourth terminal of the control module. In this way, a particularly simple adjustment of the desired switching states is possible.

According to one embodiment, the device for charging the electrical energy store in the electric vehicle comprises a power converter. The power converter includes a DC voltage port and multiple output ports. One of the output terminals of the power converter is electrically coupled to the second terminal of the control module. The further output terminals of the power converter are electrically coupled to the phase terminals of an electrical machine.

According to a further embodiment, the device for charging the electrical energy store of an electric vehicle comprises an electric machine with a plurality of phase terminals. A phase connection of the electric machine is electrically coupled to the fourth connection of the control module. The further phase connections of the electrical machine are electrically coupled to the corresponding output terminals of the power converter.

According to one embodiment, the device for charging the electrical energy storage device further comprises a battery separator. The battery separator may be electrically coupled to the control module, the power converter and the electrical energy storage. Further, the battery separator may be configured to be coupled to a DC voltage source. In particular, the battery separator may be adapted to adjust the electrical connections between the control module, the power converter, the electrical energy storage and a DC voltage source depending on an operating mode to be set. In this way, the power flow between individual components of each operating mode can be adjusted by the battery separator.

According to one embodiment, the device for charging the electrical energy store of an electric vehicle is designed to transmit electrical energy from the DC voltage source to the electrical energy store of the electric vehicle in a first operating mode. In a second operating mode, the device may be designed to transmit electrical energy from the electrical energy store of the electric vehicle to the DC voltage source.

According to a further embodiment, the device may be designed, in particular, to adjust the level of the DC voltage during the transmission of the electrical energy in the first operating mode and / or in the second operating mode.

The above embodiments and developments can, as far as appropriate, combine arbitrarily. Further refinements, further developments and implementations of the invention also include not explicitly mentioned combinations of features of the invention described above or below with regard to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the invention.

list of figures

• 1: eine schematische Darstellung einer Vorrichtung zum Laden eines Energiespeichers eines Elektrofahrzeugs gemäß einer Ausführungsform;
• 2: eine schematische Darstellung einer Schalteinrichtung in einem Steuermodul einer Vorrichtung zum Laden eines elektrischen Energiespeichers gemäß einer Ausführungsform;
• 3: eine schematische Darstellung einer Schalteinrichtung in einem Steuermodul einer Vorrichtung zum Laden eines Energiespeichers gemäß einer weiteren Ausführungsform; und
• 4: eine schematische Darstellung einer Schalteinrichtung in einem Steuermodul einer Vorrichtung zum Laden eines Energiespeichers gemäß noch einer weiteren Ausführungsform.

The present invention will be explained in more detail with reference to the exemplary embodiments given in the schematic figures of the drawings. Showing:

• 1 : a schematic representation of an apparatus for charging an energy storage of an electric vehicle according to an embodiment;
• 2 : a schematic representation of a switching device in a control module of a device for charging an electrical energy storage device according to an embodiment;
• 3 a schematic representation of a switching device in a control module of an apparatus for charging an energy storage device according to another embodiment; and
• 4 : A schematic representation of a switching device in a control module of a device for charging an energy store according to yet another embodiment.

Embodiments of the invention

In all figures, identical or functionally identical elements and devices, unless otherwise stated, provided with the same reference numerals.

1 shows a schematic representation of a block diagram of a device 1 for charging an energy storage of an electric vehicle. The device 1 includes a battery separator 10 and a control module 20 , Furthermore, in 1 a power converter 30 , an electric machine 40 , an electrical energy storage 50 For example, a traction battery of an electric vehicle, as well as a connection 60 represented for a DC voltage source. The combination of the components shown here can be arranged, for example, in an electric vehicle.

The battery separator 10 can the traction battery 50 as well as the connection 60 the external DC voltage source of the other components of the high-voltage electrical system, in particular of the power converter 30 , the electric machine 40 and the control module 20 separate. For this purpose, a first switching element 11 between a first connection of the traction battery 50 and a first connection element 31 the DC voltage connection of the converter 30 arranged. Furthermore, a second switching element 12 between a second terminal of the traction battery 50 and a second connection element 32 the DC voltage connection of the converter 30 arranged. Parallel to the second switching element 12 can be a series circuit of another switching element 16 and an electrical resistance R be provided. Furthermore, between a first connection 61 for an external DC voltage source and the first connection element 31 a DC voltage connection of the converter 30 a third switching element 13 provided and between a second connection element 62 the external DC voltage source and a second connection element 32 the DC voltage connection of the converter 30 is a fourth switching element 14 intended. In addition, between the second connection element 62 the external DC voltage source and a first terminal 21 of the control module 20 a fifth switching element 15 intended. Alternatively, it is also possible, the fourth switching element 14 between the second connection element 32 the DC voltage connection of the converter 30 and the first connection 21 of the control module 20 provided.

The switching elements 11 to 16 the battery separator 10 For example, they can be designed as mechanical switching elements or else as semiconductor switching elements. In particular, it is also possible that some of the switching elements 11 to 16 are designed as mechanical switching elements, and some of the switching elements 11 to 16 are designed as semiconductor switching elements. Depending on the application, any combinations are possible.

At the power converter 30 For example, it can be an inverter which generates a multiphase AC voltage from a DC voltage provided at the input terminal and this AC voltage at the output terminals 33 . 34 and 35 provides an electric machine 40 head for. For example, as shown here, a three-phase electrical machine 40 be controlled by means of three half-bridges of a B6 bridge. However, the present invention is not limited to three-phase electric machines and, accordingly, three-phase inverters. Rather, any multi-phase electric machine can be controlled by inverters with a corresponding number of phases. In addition, each application, any other types of power converters in particular, for example, multilevel inverter o. Ä. Possible. Furthermore, also between the two connection elements 31 and 32 the input terminal of the converter 30 a DC link capacitor C1 be provided. The switching elements of the power converter 30 are denoted by the reference numerals S1 - S6 designated.

For example, in the case of a three-phase inverter, the inverter may be formed by means of three half-bridges of a B6 bridge, as previously mentioned. Each half-bridge is formed from a series connection of two semiconductor switches with diodes arranged in parallel. The semiconductor switches can be, for example, bipolar transistors with an insulated gate connection (IGBT) or MOSFET. In principle, however, any other suitable semiconductor switches are possible. In the case of a three-phase inverter, the inverter can thus be made of the six switching elements S1 to S6 be formed.

The from the power converter 30 provided AC voltage can at the phase terminals of the electric machine 40 to be provided. The electric machine 40 can, as shown here, for example, be controlled in a star point circuit.

As in 1 can be seen further, are with the exception of the first output terminal 33 all other output connections 34 and 35 directly to the phase terminals of the electric machine 40 connected. The first output terminal 33 of the power converter 30 is with a second connection 22 of the control module 20 connected. A third connection 23 of the control module 20 is with the first connection element 31 of the power converter 30 connected and a fourth connection 24 of the control module 20 is with the remaining phase connection of the electric machine 40 connected.

The control module 20 includes a first semiconductor switch T1 that is between the first connection 21 of the control module 20 and a node K is arranged. Parallel to the first semiconductor switch T1 a diode can be arranged. Furthermore, between the third port 23 of the control module 20 and the node K of the control module 20 a second semiconductor switch T2 provided with a diode arranged in parallel. Optionally, the second semiconductor switch T2 omitted, so that between the node K and the third port 23 only one diode is provided.

Furthermore, the control module comprises 20 a switching device X , One connection each of the switching device X is with the second connection 22 , the fourth connection 24 and the node K of the control module 20 connected. Accordingly, the switching device X connect or disconnect the respective connections in any way.

Optionally, between the first port 21 and the third port 23 of the control module 20 a capacitor C2 be provided.

The individual configuration of the switching device X of the control module 20 will be described in more detail below.

2 shows a schematic diagram of the switching device X of the control module 20 according to one embodiment. In this embodiment, the switching element X designed as a changeover switch, either an electrical connection between the second port 22 and the fourth connection 24 of the control module 20 or between the node K and the fourth connection 24 manufactures.

3 shows a schematic diagram of the switching element X of the control module 20 according to a further embodiment. In this embodiment, the switching device comprises X two switching elements X1 and X2 , A first switching element X1 is between the second port 22 and the fourth connection 24 of the control module 20 arranged, and a second switching element X2 is between the fourth port 24 and the node K of the control module 20 arranged.

4 shows a schematic representation of the switching device X according to yet another embodiment. In this embodiment, the electrical connection is between the fourth port 24 and the node K hardwired. Furthermore, between the second port 22 and the fourth connection 24 of the control module 20 a switching element X1 intended.

In the switching elements of the switching device X of the control module 20 they may be any semiconductor switching elements, for example, bipolar transistors with an insulated gate, MOSFET or the like. In addition, in principle, mechanical switching elements are possible. In particular, the type and / or the type of switching elements T1 and T2 in the control module of the switching elements S1 - S6 in the power converter 30 differ.

For transmitting the electrical energy between a DC voltage source at the charging port 60 and the traction battery 50 the configurations described in the following table are possible. In all operating modes described below are the switches 11 . 12 and 13 closed. Table 1 mode Turn 14 Switch r 15 X T1 T2 S1 S2 S3 S4 S5 S6 A 0 1 1-2 1 0 1* 0 1* 0 1* 0 B 0 1 2-3 1 0 0 T 0 T 0 0 c 0 1 2-3 T 0 0 * 0 0 * 0 0 0 D 0 1 2-3 0 * 0 T 0 T 0 0 0 e 0 1 2-3 0 T 1 0 1 0 0 0 F 0 1 1-2-3 0 0 T 0 T 0 0 T G 1 0

A:

Energieübertragung direkt von dem Ladeanschluss 60 zur Traktionsbatterie 50;

B:

Energieübertragung von dem Ladeanschluss 60 zur Traktionsbatterie 50, wobei U_Lade < U_Batt;

C:

Übertragung elektrischer Energie vom Ladeanschluss 60 zur Traktionsbatterie 50, wobei U_Lade > U_Batt;

D:

Übertragung elektrischer Energie von der Traktionsbatterie 50 zum Ladeanschluss 60, wobei U_Batt > U_Lade;

E:

Übertragung elektrischer Energie von der Traktionsbatterie 50 zum Ladeanschluss 60, wobei U_Batt < U_Lade, und wobei die Schalteinrichtung X gemäß 2 ausgeführt ist;

F:

Übertragung elektrischer Energie von der Traktionsbatterie 50 zum Ladeanschluss 60, wobei U_Bat < U_Lade, und wobei die Schalteinrichtung X gemäß 3 oder 4 ausgeführt ist; und

G:

Übertragung elektrischer Energie direkt vom Ladeanschluss 60 zur Traktionsbatterie 50, analog zu Modus A, oder Übertragung elektrischer Energie von der Traktionsbatterie 50 zum Ladeanschluss 60.

The following operating modes are possible:

A:

Energy transfer directly from the charging port 60 to the traction battery 50 ;

B:

Energy transfer from the charging port 60 to the traction battery 50 , where U_Lade <U_Batt;

C:

Transmission of electrical energy from the charging port 60 to the traction battery 50 where U_Lade>U_Batt;

D:

Transmission of electrical energy from the traction battery 50 to the charging port 60 where U_Batt>U_Lade;

e:

Transmission of electrical energy from the traction battery 50 to the charging port 60 , where U_Batt <U_Lade, and wherein the switching device X according to 2 is executed;

F:

Transmission of electrical energy from the traction battery 50 to the charging port 60 , where U_Bat <U_Lade, and wherein the switching device X according to 3 or 4 is executed; and

G:

Transmission of electrical energy directly from the charging port 60 to the traction battery 50 , analogous to mode A , or transmission of electrical energy from the traction battery 50 to the charging port 60 ,

1:

ein dauerhaft eingeschaltetes Schaltelement

1*:

ein eingeschaltetes Schaltelement, wobei dieser Schaltzustand keinen Einfluss auf die Funktionalität hat

0:

ein dauerhaft ausgeschaltetes Schaltelement,

0*:

ein dauerhaft ausgeschaltetes Schaltelement, wobei der Schaltzustand keinen Einfluss auf die Funktion hat

T:

ein gezieltes Takten, das heißt kontrolliertes Ein- und Ausschalten des entsprechenden Schaltelementes

Where:

1:

a permanently switched switching element

1*:

a switched-on switching element, wherein this switching state has no effect on the functionality

0:

a permanently switched off switching element,

0 *:

a permanently switched off switching element, wherein the switching state has no effect on the function

T:

a targeted clocking, that is controlled switching on and off of the corresponding switching element

• „1-2“ eine elektrische Verbindung zwischen dem zweiten Anschluss 22 und dem Knotenpunkt K des Steuermoduls 20;
• „2-3“ eine elektrische Verbindung zwischen dem Knotenpunkt K und dem vierten Anschluss 24 des Steuermoduls 20; und
• „1-2-3“ eine elektrische Verbindung zwischen dem zweiten Anschluss 22, dem vierten Anschluss 24 und dem Knotenpunkt K des Steuermoduls 20

In column X denotes:

• "1-2" an electrical connection between the second port 22 and the node K of the control module 20 ;
• "2-3" an electrical connection between the node K and the fourth port 24 of the control module 20 ; and
• "1-2-3" an electrical connection between the second port 22 , the fourth connection 24 and the node K of the control module 20

If instead of the second semiconductor switch T2 in the control module 20 only one diode is present is the operating mode e not possible.

In the operating modes B and D For example, the two switches to be clocked can be clocked both simultaneously and with a time offset.

Both in operating mode A as well as in operating mode G is a direct transfer of energy between the charging port 60 and the traction battery 50 possible. Here, the efficiency of energy transfer is in operating mode G usually higher than in operating mode A. In the event that the operating mode G However, it may be omitted, so it is also possible, the battery separator 10 even without the switch 14 perform.

At the beginning of the respective charging operations, the DC link capacitor C1 in the power converter 30 as well as the capacitor C2 in the control module 20 be charged to a suitable voltage. Starting from an initial state in which all the switching elements 11 - 16 the battery separator 10 are opened, first, the first switching element 11 the battery separator 10 closed. Subsequently, the DC link capacitor C1 controlled by closing the sixth switching element 16 to be charged. After the DC link capacitor C1 has been charged to the desired voltage, which is parallel to the sixth switching element 16 and the resistance R arranged second switching element 12 closed. If necessary, then the sixth switching element 16 be opened. Subsequently, by driving the switching elements S1 - S6 of the power converter 30 the capacitor C2 in the control module 20 to be charged. After also the capacitor C2 in the control module 20 has been charged to the desired voltage, also the other required switching elements of the battery separator 10 , For example, the switching elements 13 and 15 getting closed.

To control the charging process and the energy transfer between the traction battery 50 and the at the charging port 60 Connected voltage source can be made wireless or wired communication with appropriate controls.

According to a further embodiment, the first connection 21 of the control module 20 with the second connection element 32 be connected to the DC voltage connection. In this case, the fifth switch element 15 the battery separator 10 between the first connection 61 for the external DC voltage source 60 and the third port 23 of the control module 20 connected. Here, however, is the third port 23 with directly to the power converter 30 connected. The control of the switches S1 - S6 of the power converter 30 and the semiconductor switch T1 and T2 takes place correspondingly adapted to the embodiment described above.

The components described above, in particular the battery separator 10 , the control module 20 and the power converter 30 , may also be realized as a common component. For example, it is possible that control module 20 and the power converter 30 as a common assembly. In addition, the components described above can also be arranged at least in a common housing. In principle, it is also possible to integrate further components in this common housing. For example, in the housing, a battery management system for the traction battery 50 , Parts of the electric machine 40 or other components, such as controllers, in particular control module for controlling the power converter 30 o. Ä. To be integrated.

In summary, the present invention relates to an extension of an existing vehicle infrastructure, in particular a power converter and an electric motor for power transmission between a traction battery of an electric vehicle and an external DC voltage source connected to a charging port. For this purpose, between an output of the power converter and a phase connection the electrical machine, an additional control module can be arranged, which extends the functionality of the existing circuit topology and the possibility of boosting or stepping down a DC voltage.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• WO 2012/038222 A2 [0003]

Claims (10)

Device (1) for charging an energy store (50) of an electric vehicle, comprising: a control module (20) adapted to be coupled to a battery disconnect device (10) at a first terminal (21) coupled to an output terminal (33) of a power converter (30) at a second terminal (22) be coupled to a first terminal (31) of a DC terminal of the power converter (30) at a third terminal (23) and coupled to a phase terminal of an electric machine (40) at a fourth terminal (24), wherein the control module (20) comprises a switching device (X), a first semiconductor switch (T1) and a second semiconductor switch (T2) or a diode, and wherein the first semiconductor switch (T1) is arranged between the first terminal (21) of the control module (20) and a node (K), the second semiconductor switch (T2) or the diode between the node (K) and the third terminal (23) of the Control module (20) is arranged, and the switching device (X) is electrically coupled to the second terminal (22), the fourth terminal (24) and the node (K). Device (1) according to Claim 1 wherein the switching means (X) of the control module (20) is adapted to either electrically connect the second terminal (22) of the control module (20) to the fourth terminal (24) of the control module (20), electrically electrically connecting the node (K) to connect to the fourth terminal (24) of the control module (20), or to electrically connect the second terminal (22), the fourth terminal (24) and the node (K) of the control module (20). Device (1) according to Claim 1 or 2 wherein the switching device (X) of the control module (20) comprises at least one semiconductor switch. Device (1) according to one of the preceding claims, wherein the switching device (X) of the control module (20) comprises a first switch (X1) connected between the second terminal (22) of the control module (20) and the fourth terminal (24) of the Control module (20) is arranged and a second switch (X2), which is arranged between the node and the fourth terminal (24) of the control module (20). Device (1) according to one of Claims 1 to 3 wherein the switching means (X) of the control module (20) comprises a switch (X1) arranged electrically between the second terminal (22) of the control module (20) and the node (K) in the control module (20), and wherein the node (K) is electrically coupled to the fourth terminal (24) of the control module (20). Device (1) according to one of the preceding claims, comprising a power converter (30) which comprises a DC voltage connection and a plurality of output connections (33, 34, 35), one of the output connections (33) being electrically connected to the second connection (22) of the control module (33). 20) and the further output terminals (34, 35) are electrically coupled to phase terminals of an electric machine (40). Device (1) according to Claim 6 , an electrical machine (40) having a plurality of phase terminals, wherein a phase terminal of the electric machine (40) is electrically coupled to the fourth terminal (24) of the control module (20), and wherein the other phase terminals of the electric machine (40) electrically the output terminals (34, 35) of the power converter (30) are coupled. Device (1) according to Claim 6 or 7 a battery separator (10) electrically coupled to the control module (20), the power converter (30) and the electrical energy store (50), and adapted to be coupled to a DC power source (60), and wherein the battery separator (10) is further adapted to adjust the electrical connections between the control module (20), the power converter (30), the electrical energy store (50) and the DC voltage source (60) in dependence on an operating mode to be set. Device (1) according to one of the preceding claims, wherein the device (1) is adapted to transmit electrical energy from the DC voltage source (60) to the electric energy storage (50) of the electric vehicle in a first operating mode, and electrical energy in a second operating mode from the electrical energy store (50) of the electric vehicle to the DC voltage source (60) to transmit. Device (1) according to Claim 9 wherein the device (1) is further adapted to adjust the voltage level during the energy transfer.

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