Circuit Arrangement for a Motor Vehicle, in Particular for a Hybrid or Electric Vehicle

Abstract

A circuit arrangement of a motor vehicle includes a high-voltage battery for storing electrical energy, an electric machine for driving the motor vehicle, a converter via which high-voltage direct current voltage provided by the high-voltage battery is convertible into high-voltage alternating current voltage for operating the electric machine, and a charging connection for providing electrical energy for charging the high-voltage battery. The converter is a three-stage converter having a first switch unit which is assigned to a first phase of the electric machine. The first switch unit has two switch groups connected in series which each have two insulated-gate bipolar transistors (IGBTs) connected in series, where a connection is disposed between the IGBTs of one of the two switch groups, which connection is electrically connected directly to a line of the charging connection.

Claims

1.-9. (canceled)

10. A circuit arrangement (10) of a motor vehicle, comprising: a high-voltage battery (12) for storing electrical energy; an electric machine (14) for driving the motor vehicle; a converter (16) via which high-voltage direct current (DC) voltage provided by the high-voltage battery (12) is convertible into high-voltage alternating current (AC) voltage for operating the electric machine (14); and a charging connection (20) for providing electrical energy for charging the high-voltage battery (12), wherein the charging connection (20) has a first line (34) and a second line (36); wherein the high-voltage battery (12) has a first battery segment (28) and a second battery segment (30) which are interconnected via a center tap (32) of the high-voltage battery (12); wherein the converter (16) is a three-stage converter having: a first switch unit (46) which is assigned to a first phase (u) of the electric machine (14); a second switch unit (48) which is assigned to a second phase (v) of the electric machine (14); and a third switch unit (50) which is assigned to a third phase (w) of the electric machine (14); wherein the first switch unit (46) has two switch groups (52, 54) connected in series which each have two insulated-gate bipolar transistors (IGBTs) (T11, T12, T13, T14) connected in series, wherein a connection (64) is disposed between the IGBTs (T11, T12) of one of the two switch groups (52, 54), which connection (64) is electrically connected directly to the first line (34) of the charging connection (20); a first switching state in which at least the first battery segment (28) of the high-voltage battery (12) is connected to the charging connection (20) via the three-stage converter and at least the second battery segment (30) of the high-voltage battery (12) is decoupled from the charging connection (20) by the converter (16) such that the first battery segment (28) can be charged via the three-stage converter with electrical energy provided by the charging connection (20); a second switching state in which at least the second battery segment (30) of the high-voltage battery (12) is connected to the charging connection (20) via the three-stage converter and the first battery segment (28) of the high-voltage battery (12) is decoupled from the charging connection (20) by the converter (16) such that the second battery segment (30) can be charged via the three-stage converter with electrical energy provided by the charging connection (20); and a third switching state in which both the first battery segment (28) and the second battery segment (30) of the high-voltage battery (12) are connected to the charging connection (20) via the three-stage converter such that the first battery segment (28) and the second battery segment (30) can be charged via the three-stage converter with electrical energy provided by the charging connection (20).

11. The circuit arrangement (10) according to claim 10, wherein, in the first switching state of the converter (16), the first battery segment (28) can be charged with electrical energy of a voltage (U1) of the charging connection (20) provided by the charging connection (20) starting from the charging connection (20) via the first line (34) of the charging connection (20), the first switch unit (46) of the converter (16), the first battery segment (28) of the high-voltage battery (12), the center tap (32) of the high-voltage battery (12), via the second switch unit (48) of the converter (16) and via the second line (36) of the charging connection (20).

12. The circuit arrangement (10) according to claim 10, wherein, in the second switching state of the converter (16), the second battery segment (30) can be charged with electrical energy of a voltage (U1) of the charging connection (20) provided by the charging connection (20) starting from the charging connection (20) via the first line (34) of the charging connection (20), the first switch unit (46) of the converter (16), the center tap (32) of the high-voltage battery (12), the second battery segment (30) of the high-voltage battery (12), via the second switch unit (48) of the converter (16) and via the second line (36) of the charging connection (20).

13. The circuit arrangement (10) according to claim 10, wherein, in the third switching state of the converter (16), the first battery segment (28) is connected in series to the second battery segment (30) by a series connection such that the series connection of the first battery segment (28) to the second battery segment (30) can be charged via the converter (16) with electrical energy of a voltage (U2) provided by the charging connection (20) starting from the charging connection (20) via the first line (34) of the charging connection (20), the first switch unit (46) of the converter (16), the first battery segment (28) of the high-voltage battery (12), the center tap (32) of the high-voltage battery (12), the second battery segment (30) of the high-voltage battery (12), via the second switch unit (48) of the converter (16) and via the second line (36) of the charging connection (20).

14. The circuit arrangement (10) according to claim 10, wherein no switching state of the converter (16) exists in which the third switch unit (50) of the converter (16) is directly electrically connected to the first line (34) of the charging connection (20) and/or the second line (36) of the charging connection (20).

15. The circuit arrangement (10) according to claim 10, wherein at least one contactor (24) of the charging connection (20) is disposed in the first line (34) of the charging connection (20).

16. The circuit arrangement (10) according to claim 10, wherein the second switch unit (48) has two switch groups (56, 58) connected in series which each have two IGBTs (T21, T22, T23, T24) connected in series, wherein a connection (66) is disposed between the IGBTs (T23, T24) of one of the two switch groups (56, 58), which connection (66) is electrically connected directly to the second line (36) of the charging connection (20).

17. The circuit arrangement (10) according to claim 16, wherein at least one contactor (24) of the charging connection (20) is disposed in the second line (36) of the charging connection (20).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a schematic depiction of a circuit arrangement according to the invention for a motor vehicle designed, for example, as a hybrid or electric vehicle;

[0020] FIG. 2 is a schematic depiction of the circuit arrangement in a first switching state;

[0021] FIG. 3 is a schematic depiction of the circuit arrangement in a second switching state; and

[0022] FIG. 4 is a schematic depiction of the circuit arrangement in a third switching state.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0024] FIG. 1 shows a schematic depiction of a circuit arrangement 10 for a motor vehicle. This means that the motor vehicle in its fully manufactured state has the circuit arrangement 10. The motor vehicle is designed, for example, as a hybrid or preferably electric vehicle, in particular as a battery-electric vehicle. The circuit arrangement 10 has a high-voltage battery 12 for storing electrical energy or electrical current, which is depicted particularly schematically in FIG. 1 and is also simply referred to as a battery. In addition, the circuit arrangement comprises at least one electric machine 14, which has, in particular precisely, three phases u, v and w. The electric machine 14 can be operated, for example, in an engine mode and thus as an electric engine. In order to operate the electric machine 14 in the engine mode, the electric machine 14 is supplied with an electric alternating voltage, in particular an electric high-voltage alternating voltage, via the phases u, v and w, in particular via phase lines or phase connection associated with the phases u, v and w.

[0025] The circuit arrangement 10 further comprises a converter 16, by means of which high-voltage DC voltage which can be or is provided by the high-voltage battery 12 can be converted into high-voltage AC voltage for operating the electric machine 14. In other words, the high-voltage battery 12 has a high-voltage DC voltage which is, for example, 800 volts. This means that the high-voltage battery 12 can provide the high-voltage DC voltage. In at least one switching state of the converter 16, the converter 16 converts the high-voltage DC voltage provided by the high-voltage battery 12 into high-voltage AC voltage provided by the converter 16. The high-voltage AC voltage provided by the converter 16 can be supplied to the electric machine 14, in particular via the phase lines, such that the electric machine 14, in particular the phase lines, can be supplied or is supplied with the high-voltage AC voltage provided by the converter 16. As a result, the electric machine 14 is operated as an electric engine by means of the high-voltage AC voltage provided by the converter 16 and thus in the engine mode. As a result, the motor vehicle can be electrically driven by means of the electric engine.

[0026] The circuit arrangement 10 has a charging connection 20. The charging connection 20 can provide electrical energy, in particular with a high-voltage DC voltage, wherein the high-voltage battery 12 can be charged with the electrical energy provided by the charging connection 20. This means that the electrical energy provided by the charging connection 20 can be fed into the high-voltage battery 12 and thus stored in the battery.

[0027] FIG. 1 also shows, particularly schematically, an energy source external to the motor vehicle and thus external to the circuit arrangement 10 and provided in addition thereto, presently in the form of a charging column 22. The charging column 22 can provide electrical energy with which the high-voltage battery 12 can be charged. For this purpose, the charging column 22 can be electrically connected to the charging connection 20. As a result, the electrical energy provided by the charging column 22 can be transferred to the charging connection 20 and provided by the charging connection 20, such that the electrical energy provided by the charging column 22 can be transferred to the high-voltage battery 12 via the charging connection 20. As a result, the electrical energy provided by the charging station 22 can be stored in the battery.

[0028] The charging connection 20 has a line arrangement 18 having a first line 34 and a second line 36, through which the electrical energy that can be or is provided by the charging connection 20 can flow. In other words, the electrical energy provided by the charging column 22 and used to charge the battery can run or flow through the lines 34 and 36.

[0029] The charging connection 20 also has a first contact 38 electrically connected to the line 34 and a second contact 40 electrically connected to the line 36, to which the charging column 22 is electrically connectable. Thus, the electrical energy provided by the charging column 22 can be transmitted to the contacts 38, 40 and fed into the lines 34 and 36 and the charging connection 20 via the contacts 38, 40. The lines 34 and 36 and thus the charging connection 20 are thereby electrically connected to the converter 16. Thereby, an optionally provided contactor 24 is arranged in the line arrangement 18, which comprises two switches 42 and 44. The switch 42 is arranged in the line 34 and the switch 44 is arranged in the line 36. The respective switch 42 or 44 is switchable between a respective open state and a respective closed state. If, for example, the switch 42 is in its open state, the line 34 is interrupted such that the contact 38 is decoupled or disconnected, in particular electrically isolated, from the converter 16. If the switch 42 is closed, the line 34 is closed, such that the contact 38 is electrically connected to the converter 16. If the switch 44 is in its open state, the line 36 is interrupted, whereby the contact 40 is decoupled or separated, in particular electrically isolated, from the converter 16. However, if the switch 44 is in its closed state, the line 36 is closed, whereby the contact 40 is electrically connected to the converter 16. By using the contactor 24, a particularly safe operation can be implemented.

[0030] In order to be able to charge the battery in a particularly advantageous manner, the converter is designed as a three-stage converter, wherein the converter 16 has, in particular precisely, three switch units 46, 48 and 50. The switch unit 46 is assigned to the phase u, wherein the switch unit 48 is assigned to the phase v, and the switch unit 50 is assigned to the phase w of the electric machine 14. The electric machine 14 is thus designed as a multiphase, in particular as a three-phase, electric machine. In the exemplary embodiment illustrated in FIG. 1, the switch unit 46 is electrically connected or connectable to the phase u, wherein the switch unit 48 is electrically connected or connectable to the phase v, and the switch unit 50 is electrically connected or connectable to the phase w.

[0031] The respective switch unit 46, 48 or 50 has, in particular precisely, two switch groups 52 and 54 or 56 and 58 or 60 and 62 connected in series. The switch group 52 has, in particular precisely, two IGBTs T11 and T12 connected in series. Furthermore, the switch group 54 has, in particular precisely, two IGBTs T13 and T14 connected in series, wherein the switch groups 52 and 54 are connected in series to each other. The switch group 56 has two, in particular precisely two, IGBTs T21 and T22 connected in series to each other, and the switch group 58 has, in particular precisely, two IGBTs T23 and T24 connected in series to each other. The switch group 60 has, in particular precisely, two IGBTs T31 and T32 connected in series to each other, and the switch group 62 has, in particular precisely, two IGBTs T33 and T34 connected in series to each other.

[0032] A first connection 64, also referred to as a first tap, is arranged between the IGBTs T11 and T12 of the switch group 52, which is electrically connected directly to the line 34 of the charging connection 20. Here, a second connection 66, also referred to as a second tap, is arranged between the IGBTs T23 and T24 of the switch group 58, which is directly electrically connected to the line 36 of the charging connection 20. Compared to conventional three-stage converters, the connections 64 and 66 are additionally provided connections, wherein these additional connections 64 and 66 are directly connected to the charging connection 20. Additional separating elements are not required and are not provided.

[0033] The high-voltage battery 12 has at least two battery segments 28 and 30, which are connected to each other in series, for example. In order to be able to charge the battery particularly advantageously, the converter 16 is designed as a three-stage converter. The three-stage converter is also referred to as a three-level inverter, which is integrated in the motor vehicle, for example. The converter 16 comprises individual IGBTs T11, T12, T13, T14, T21, T22, T23, T24, T31, T32, T33 and T34 (IGBT—insulated-gate bipolar transistor). As will be further explained below, the use of the three-stage converter makes it possible to charge the battery, in particular via the intermediate circuit 26, both by means of those charging columns which provide electrical energy with a high-voltage DC voltage of 800 volts, and by means of those charging columns which provide electrical energy with a high-voltage DC voltage of 400 volts. In other words, the three-stage converter makes it possible to charge an intermediate circuit voltage of 800 volts with 400-volt charging columns and with 800-volt charging columns.

[0034] Typically, drive systems with an intermediate circuit voltage of 400 volts have been used until now in motor vehicles, particularly all-electric motor vehicles, in particular in conjunction with a two-stage converter. However, an intermediate circuit voltage of 800 volts, i.e., a high-voltage DC voltage of 800 volts for the high-voltage battery 12, is particularly advantageous, as it allows particularly high electrical outputs to be implemented for electrical driving.

[0035] However, in order to be able to charge such batteries with 800 volts of voltage, in particular intermediate circuit voltage, with an existing charging infrastructure which can provide a maximum of 400 volts DC, an additional voltage converter must be integrated into the motor vehicle or new charging columns are required which provide 800 volts DC. This leads to high costs. The circuit arrangement 10 now makes it possible to charge the high-voltage battery 12, whose high-voltage DC voltage is 800 volts, for example, both by means of charging infrastructures which can provide 800 volts DC voltage and by means of charging infrastructures which can provide a maximum of 400 volts DC voltage.

[0036] For this purpose, instead of a two-stage converter, the converter 16 designed as a three-stage converter is used. The converter 16 has a first switching state shown in FIG. 2 or can be operated in the first switching state shown in FIG. 2. By way of example, in the exemplary embodiment illustrated in FIG. 2, the charging column 22 provides electrical energy with a high-voltage DC voltage U1, which is 400 volts. Here, in the first switching state, the battery segment 28 is electrically connected to the charging connection 20 via the converter 16, while the battery segment 30 is decoupled from the charging connection 20, in particular by means of the converter 16. As a result, the battery segment 28 is charged with the electrical energy provided by the charging station 22, while charging of the battery segment 30 is omitted.

[0037] The converter 16 further has a second switching state shown in FIG. 3. In the exemplary embodiment shown in FIG. 3, the charging column 22 also provides the electrical energy with the high-voltage DC voltage U1, which is 400 volts. In the second switching state, however, the battery segment 30 is electrically connected to the charging connection 20 via the converter 16, while the battery segment 28 is separated, in particular electrically isolated, or decoupled from the charging connection 20, in particular by means of the converter 16. As a result, the battery segment 30 is charged with the electrical energy provided by the charging column 22.

[0038] FIG. 4 shows an exemplary embodiment, in which the charging column 22 provides electrical energy with a high-voltage DC voltage U2. The high-voltage DC voltage U2 is 800 volts. Thus, the high-voltage DC voltage U2 corresponds to the high-voltage DC voltage of the battery. In the third switching state, both the battery segment 28 and the battery segment 30 are connected to the charging connection 20 via the converter 16, such that the battery segments 28 and 30 are simultaneously charged via the converter 16 with the electrical energy provided by the charging column 22. Furthermore, in the first switching state, in the second switching state and in the third switching state, the contactor 24 is closed, such that the charging connection 20 is electrically connected to the converter 16.

[0039] The charging connection 20 is, for example, a charging junction box to which both 400-volt charging columns and 800-volt charging columns can be connected. The battery segments 28 and 30 are also referred to as blocks into which the battery is divided. The respective block has a respective high-voltage DC voltage, which is 400 volts, for example. Thus, the high-voltage DC voltages of the blocks add up to the high-voltage DC voltage of the battery as a whole. Furthermore, the high-voltage DC voltages of the blocks are at least substantially equal. In order to divide the battery into the blocks or to be able to charge the blocks independently or separately from each other, a center tap 32 also referred to as an intermediate voltage tap is provided. The center tap 32 is electrically connected, for example, to a so-called neutral point of the three-stage converter.

[0040] The electrical energy or electrical voltage that can be provided by the charging column 22 is also referred to as the charging voltage.

[0041] By way of example, in order to charge the battery segment 28 by means of the charging column 22 as shown in FIG. 2, the IGBTs T22 and T23 are switched in order to electrically connect, for example, the charging connection 20 and, via this, the charging column 22 to the battery segment 28. As a result, the battery segment 28 can be charged, in particular recharged, with or to 400 volts.

[0042] By way of example, as shown in FIG. 3, in order to charge the battery segment 30 by means of the charging column 22, the IGBTs T12 and T13 are switched and thus conductive. According to FIG. 4, the battery can be charged directly via the diodes using the charging column 22, the provided energy of which is 800 volts according to FIG. 4.

[0043] By using the additional connections 64 and 66, the lines 34 and 36 can be directly connected to the converter 16, such that the lines 34 and 36 can bypass the phase line of the phases u, v and w. In other words, the lines 34 and 36 need not be connected to the phase line of phases u, v and w, but rather the lines 34 and 36 are electrically connected directly to the converter 16, bypassing the phase lines of phases u, v and w, and thereby to the connections 64 and 66.