On-board electrical system arrangement for an electrically powered vehicle and methods for its operation

Abstract

The invention relates to an on-board electrical system arrangement (1) comprising: a high-voltage battery (2), a high-voltage electrical system (3), a low-voltage electrical system (6), a low-voltage power source (7), and a DC / DC converter (8). The high-voltage electrical system (3) and the high-voltage battery (2) are interconnected via main potential lines (HV+, HV-) with switching elements (S+, S-). A low-voltage side (LV) of the DC / DC converter (8) is connected to the low-voltage electrical system (6) and the low-voltage power source (7), and a negative potential connection line (AL-) of the DC / DC converter (8) is connected to a high-voltage side (HV) of the DC / DC converter (8) and to the high-voltage battery (2). According to the invention, a positive potential connection line (AL+) of the DC / DC converter (8), in which a disconnect switch (TS) is arranged, is connected to the high-voltage side (HV) of the DC / DC converter (8) and to the high-voltage battery (2), and a positive potential bypass line (BL+) to the switching element (S+) arranged in the positive potential main line (HV+), in which a pre-charge switch (VS+) is arranged, is connected between the high-voltage side (HV) of the DC / DC converter (8) and the disconnect switch (TS) to the positive potential connection line (AL+) and between the switching element (S+) arranged in the positive potential main line (HV+) and the high-voltage vehicle electrical system (3) to the positive potential main line (HV+).

Description

[0001] The invention relates to an on-board electrical system arrangement for an electrically powered vehicle according to the features of the preamble of claim 1 and a method for its operation.

[0002] As described in DE 10 2013 225 884 A1, a method for precharging an electrical intermediate circuit storage device is known from the prior art. In a method for operating an electrical system of a motor vehicle with the intermediate circuit storage device, a high-voltage energy storage device coupled to the intermediate circuit storage device, and a low-voltage energy storage device coupled to the intermediate circuit storage device via a voltage converter, the intermediate circuit storage device is precharged via the voltage converter using electrical energy from the low-voltage energy storage device.

[0003] German patent application DE 10 2015 209 081 A1 describes an electrical system and a method for precharging a DC link capacitor of the electrical system. The electrical system comprises a high-voltage battery, a low-voltage battery, a DC / DC converter arranged between the high-voltage and low-voltage batteries, a power relay between the high-voltage battery and the DC / DC converter, and a DC link capacitor. The electrical system includes at least one circuit for precharging the DC link capacitor, which is designed as a galvanically isolated DC / DC converter connected to a voltage source in the electrical system. The DC / DC converter is configured to transfer electrical energy to a high-voltage side containing the DC link capacitor for precharging the DC link capacitor.

[0004] German patent application DE 10 2022 000 832 A1 discloses a method and a system for pre-charging the high-voltage electrical system of an electric vehicle. The high-voltage electrical system comprises a high-voltage energy storage device, driving-related high-voltage components, and non-driving-related high-voltage components. The high-voltage energy storage device is coupled to the driving-related and non-driving-related high-voltage components as needed via a switch. The high-voltage electrical system is coupled to a low-voltage electrical system via a DC / DC converter. A switching element is arranged in the high-voltage electrical system, which allows the non-driving-related high-voltage components to be electrically disconnected as needed.In this process, the switching element for disconnecting the non-driving-relevant high-voltage components is opened, the driving-relevant high-voltage components are pre-charged via the DC / DC converter from the low-voltage electrical system while the switch of the high-voltage energy storage unit is open, the switch of the high-voltage energy storage unit is closed and the pre-charging is stopped.

[0005] German patent DE 10 2022 100 994 A1 describes a pre-charging process using a bidirectional DC / DC converter and an auxiliary battery. A power control arrangement for a vehicle includes the bidirectional DC / DC converter and a controller. Upon a request to activate the vehicle, the controller instructs the bidirectional DC / DC converter to electrically charge a DC link capacitor between the main contactors and the bidirectional DC / DC converter to a setpoint value, without connecting a resistor in parallel to any of the main contactors and before all main contactors are closed.

[0006] German patent DE 10 2020 006 443 A1 discloses a high-voltage electrical system for a vehicle, a vehicle with a high-voltage electrical system, and a method for operating a high-voltage electrical system for a vehicle. The high-voltage electrical system comprises a high-voltage battery, an electric drive unit, an auxiliary electrical unit, and a bidirectional low-voltage DC / DC converter. A drive potential conductor pair with a drive disconnect device is provided for the electrical connection of the electric drive unit to the high-voltage battery. An auxiliary unit potential conductor pair with an auxiliary unit disconnect device is provided for the electrical connection of the auxiliary electrical unit and the low-voltage DC / DC converter to the high-voltage battery.A pre- and discharge circuit is provided, which includes a pre- and discharge separation arrangement in a connecting potential line pair coupled with the auxiliary unit potential line pair and the drive potential line pair.

[0007] German patent application DE 10 2020 005 525 A1 describes a method for operating a high-voltage energy storage device in the high-voltage network of an electrically powered vehicle. The high-voltage network comprises the high-voltage energy storage device with a pre-charging circuit and a DC link capacitor. With the switches between the high-voltage energy storage device and the high-voltage network open, the pre-charging function of the pre-charging circuit is checked before the high-voltage energy storage device is connected to the high-voltage network. If the pre-charging function is not functioning, the pre-charging function is transferred to another pre-charging-capable component, a voltage from the high-voltage energy storage device is transmitted to this component, the DC link capacitor is charged by the component until the voltage difference between the DC link capacitor and the high-voltage energy storage device falls below a predetermined limit, and the high-voltage energy storage device is then connected to the DC link capacitor.

[0008] The generic document DE 10 2022 212 442 A1 relates to a device for precharging the intermediate circuit from the low-voltage electrical system by means of a DC-DC converter with a first converter stage and a second converter stage. The second converter stage can be connected via a control switch and an inductor, optionally to a first positive terminal of the battery or a second positive terminal of the battery as a center tap, wherein the second converter stage is directly connected to a negative terminal of the battery.

[0009] The invention is based on the objective of providing an improved on-board network arrangement for an electrically powered vehicle compared to the prior art and an improved method for its operation compared to the prior art.

[0010] The problem is solved according to the invention by an on-board power supply arrangement for an electrically powered vehicle with the features of claim 1 and a method for operating it with the features of claim 7 or 9.

[0011] Advantageous embodiments of the invention are the subject of the dependent claims.

[0012] An electrical system for an electric vehicle comprises a high-voltage battery, a high-voltage electrical system, a low-voltage electrical system, a low-voltage power source, and a bidirectional DC / DC converter. The DC / DC converter is also known as a DC-DC converter.

[0013] The low-voltage electrical system includes at least one or more low-voltage consumers.

[0014] The high-voltage electrical system includes, in particular, one or more high-voltage components, especially high-voltage consumers.

[0015] The high-voltage electrical system and the high-voltage battery can be optionally connected to each other or disconnected from each other via a positive potential main line and a negative potential main line, each with a switching element of a main switch arrangement.

[0016] One low-voltage side of the DC / DC converter is connected to the low-voltage electrical system and the low-voltage power source.

[0017] A negative potential connection lead of the DC / DC converter is connected on one side to a high-voltage side of the DC / DC converter, in particular directly, and on the other side directly to the high-voltage battery, in particular to the negative potential of the high-voltage battery. "Directly connected" means, in particular, connected without any intermediate switches. The side of the negative potential connection lead of the DC / DC converter facing away from the high-voltage side of the DC / DC converter is connected, in particular, between the high-voltage battery and the switching element of the main switch assembly located in the negative potential main line, and thus, via this section of the negative potential main line, directly to the high-voltage battery, in particular to the negative potential of the high-voltage battery.The high-voltage side of the DC / DC converter is therefore directly connected to the high-voltage battery, in particular to its negative potential, via the negative potential connection line and the negative potential main line.

[0018] According to the invention, a positive potential connection line of the DC / DC converter, in which a disconnect switch is arranged, is connected on one side to the high-voltage side of the DC / DC converter, in particular directly, and on the other side directly to the high-voltage battery, in particular to a positive potential of the high-voltage battery. Direct connection means in particular that no further switches are interposed between the disconnect switch and the high-voltage battery. The side of the positive potential connection line of the DC / DC converter facing away from the high-voltage side of the DC / DC converter is in particular connected between the high-voltage battery and the switching element of the main switch arrangement located in the positive potential main line to the positive potential main line and thus, via this section of the positive potential main line, directly to the high-voltage battery, in particular to the positive potential of the high-voltage battery.The high-voltage side of the DC / DC converter is thus directly connected to the high-voltage battery, in particular to its positive potential, via the positive potential connection line, the disconnect switch and the positive potential main line, either when the disconnect switch is closed, or connectable when the disconnect switch is open. According to the invention, a positive potential bypass line is provided to the switching element of the main switch assembly located in the positive potential main line, i.e., in particular as a bypass to this switching element of the main switch assembly located in the positive potential main line. A pre-charge switch is arranged in the positive potential bypass line. The positive potential bypass line is connected on one side between the high-voltage side of the DC / DC converter and the disconnect switch to the positive potential connection line of the DC / DC converter, and on the other side between the switching element of the main switch assembly located in the positive potential main line and the high-voltage vehicle electrical system to the positive potential main line.

[0019] The terms “connectable” and “connected” used in this patent application mean in particular electrically conductive connectable and electrically conductive connected.

[0020] The DC / DC converter, which has a low-voltage side and a high-voltage side, is also called an LV DC / DC converter or low-voltage DC / DC converter.

[0021] An electrically powered vehicle, in particular, has such an on-board electrical system arrangement. The high-voltage battery is specifically configured to supply electrical energy to at least one electric drive motor for propelling the vehicle.

[0022] The low-voltage energy source is, for example, a low-voltage battery or the low-voltage side of another DC / DC converter, also known as a DC-DC converter, wherein a high-voltage side of the other DC / DC converter is directly connected to the high-voltage battery, for example, by connecting the high-voltage side of the other DC / DC converter between the respective switching element of the main switch assembly and the high-voltage battery to the respective main potential conductor. "Directly connected" specifically means without a switch between the high-voltage side of the other DC / DC converter and the high-voltage battery.

[0023] The other DC / DC converter, which has a low-voltage side and a high-voltage side, is also called an LV DC / DC converter or low-voltage DC / DC converter.

[0024] The disconnect switch is designed, for example, as a semiconductor switch.

[0025] In one embodiment, the respective switching element of the main switch arrangement is designed as a contactor, or one switching element of the main switch arrangement is designed as a contactor and the other switching element of the main switch arrangement is designed as a semiconductor switch.

[0026] In this embodiment, for example, the pre-charging switch is designed as a relay or as a semiconductor switch.

[0027] In this embodiment, for example, it is provided that a control unit of the on-board network arrangement is configured to pre-charge the high-voltage on-board network, in particular at least one capacitor, in particular at least one intermediate circuit capacitor, when the switching element of the main switch arrangement in the positive potential main line and the disconnect switch are open, and to control the DC / DC converter to convert a low-voltage voltage provided by the low-voltage energy source into a high-voltage voltage in the high-voltage on-board network.

[0028] In this embodiment, it is further provided, for example, that a voltage sensor for detecting the voltage in the high-voltage on-board network is arranged and connected to the control system, wherein the control system is configured to close the switching element of the main switch arrangement in the positive potential main line as soon as the high-voltage on-board network reaches the voltage level of the high-voltage battery or another sufficient voltage level, and, in particular thereafter, to close the disconnect switch and, in particular thereafter, to open the pre-charge switch.

[0029] In a method according to the invention for operating the on-board power supply arrangement, in particular this embodiment of the on-board power supply arrangement, for pre-charging the high-voltage on-board power supply, in particular at least one capacitor, in particular at least one intermediate circuit capacitor, with the switching element of the main switch arrangement in the positive potential main line open and the disconnect switch open, the switching element of the main switch arrangement in the negative potential main line and the pre-charging switch are closed, and a low-voltage voltage provided by the low-voltage energy source is converted into a high-voltage voltage in the high-voltage on-board power supply by the DC / DC converter, which is then advantageously fed into the high-voltage on-board power supply via the closed pre-charging switch and the closed switching element of the main switch arrangement in the negative potential main line.

[0030] Furthermore, it is specifically provided that the switching element of the main switch arrangement in the positive potential main line is closed as soon as the high-voltage on-board network reaches the voltage level of the high-voltage battery or another sufficient voltage level, and, in particular thereafter, the disconnect switch is closed and, in particular thereafter, the pre-charge switch is opened.

[0031] In a further embodiment, the main switch arrangement is designed as a two-pole contactor. In this embodiment, a negative potential bypass line is additionally provided to the switching element of the main switch arrangement located in the negative potential main line, i.e., specifically as a bypass to this switching element of the main switch arrangement located in the negative potential main line. A further pre-charge switch is then arranged in this negative potential bypass line.The negative potential bypass line is connected on the one hand to the negative potential connection line of the DC / DC converter, in particular between the high-voltage side of the DC / DC converter and the high-voltage battery, in particular its negative potential, in particular between the high-voltage side of the DC / DC converter and the section of the negative potential main line between the switching element of the main switch arrangement in the negative potential main line and the high-voltage battery, in particular its negative potential, and on the other hand the negative potential bypass line between the switching element of the main switch arrangement arranged in the negative potential main line and the high-voltage vehicle electrical system is connected to the negative potential main line.

[0032] In this embodiment, for example, one pre-charging switch is designed as a semiconductor switch and the other pre-charging switch is designed as a relay, or for example, the respective pre-charging switch is designed as a relay.

[0033] In this embodiment, for example, it is provided that a control system for the on-board network is configured to close the pre-charging switches and control the DC / DC converter to convert a low-voltage voltage provided by the low-voltage energy source into a high-voltage voltage in the high-voltage on-board network in order to pre-charge the high-voltage on-board network, in particular at least one capacitor, in particular at least one intermediate circuit capacitor, when the main switch arrangement and the disconnect switch are open.

[0034] In this embodiment, it is further provided, for example, that a voltage sensor for detecting the voltage in the high-voltage electrical system is arranged and connected to the control system, wherein the control system is configured to close the main switch arrangement as soon as the high-voltage electrical system reaches the voltage level of the high-voltage battery or another sufficient voltage level, and, in particular thereafter, to close the disconnect switch and, in particular thereafter, to open the pre-charge switches.

[0035] In an inventive method for operating the on-board power supply arrangement, in particular this embodiment of the on-board power supply arrangement, to pre-charge the high-voltage on-board power supply, in particular at least one capacitor, in particular at least one intermediate circuit capacitor, with the main switch arrangement and the disconnect switch open, the pre-charge switches are closed and a low-voltage voltage provided by the low-voltage energy source is converted by the DC / DC converter into a high-voltage voltage in the high-voltage on-board power supply, which is then advantageously fed into the high-voltage on-board power supply via the closed pre-charge switches.

[0036] Furthermore, it is specifically provided that the main switch arrangement is closed as soon as the high-voltage on-board network reaches the voltage level of the high-voltage battery or another sufficient voltage level, and, in particular thereafter, the disconnect switch is closed and, in particular thereafter, the pre-charge switches are opened.

[0037] The high-voltage electrical system, in particular the at least one capacitor, in particular the at least one intermediate circuit capacitor, is in particular pre-charged as soon as the high-voltage electrical system reaches the voltage level of the high-voltage battery or the other sufficient voltage level.

[0038] Pre-charging of the high-voltage electrical system, in particular of the at least one capacitor, in particular of the at least one intermediate circuit capacitor, is carried out in particular when the high-voltage battery is disconnected from the high-voltage electrical system by the open main switch arrangement, the high-voltage electrical system, in particular of the at least one capacitor, in particular of the at least one intermediate circuit capacitor, is discharged and the main switch arrangement is to be closed, i.e. the high-voltage battery is to be connected to the high-voltage electrical system.

[0039] Closing the disconnect switch supplies the DC / DC converter with electrical energy from the high-voltage battery.

[0040] Closing the disconnect switch enables, in particular, a low-voltage electrical power supply to the low-voltage vehicle electrical system and / or the low-voltage battery via the DC / DC converter and the high-voltage battery, i.e., through the high-voltage battery via the DC / DC converter, whose high-voltage side is connected to the high-voltage battery, especially directly, when the disconnect switch is closed.

[0041] In the described solution, the high-voltage electrical system, in particular the at least one capacitor, especially the at least one intermediate circuit capacitor, is advantageously pre-charged by the DC / DC converter, which, when the disconnect switch is closed, is directly connected to the high-voltage battery, particularly during normal operation, especially driving operation, of the vehicle. During pre-charging, i.e., during the pre-charging of the high-voltage electrical system, in particular the at least one capacitor, especially the at least one intermediate circuit capacitor, the disconnect switch is open.

[0042] By directly connecting the DC / DC converter to the high-voltage battery when the disconnect switch is closed, a high availability of the DC / DC converter is achieved. Furthermore, the separate connection of the DC / DC converter in parallel to the main contactors allows the DC / DC converter to continue operating even when the high-voltage electrical system is switched off by opening the contactors, which can occur, for example, in an accident or crash.

[0043] The disconnect switch, and in particular its opening function, also enables, for example, reduced quiescent current consumption. The disconnect switch is specifically designed for a low high-voltage rated current of the DC / DC converter and can, for example, be implemented as a semiconductor switch. The disconnect switch also ensures high availability of the DC / DC converter, as it can be flexibly and independently connected to the high-voltage battery and is therefore independent of the availability of the high-voltage electrical system.

[0044] The described solution eliminates the need for any ohmic resistance element, i.e., no additional pre-charge resistor, particularly in the at least one or respective bypass line, and therefore none is present there. Pre-charging of the high-voltage electrical system, particularly of the at least one capacitor, and especially of the at least one intermediate circuit capacitor, is enabled as described above, specifically by means of the pre-charge switch arranged and actuated as described, or by means of the two pre-charge switches arranged and actuated as described.

[0045] In the described solution, at least one switchable bypass is provided for the switching element of the main switch assembly located in the positive potential main line, or, in particular, a switchable bypass is provided for each switching element of the main switch assembly located in the respective potential main line. This allows the high-voltage electrical system, and in particular the at least one capacitor, and especially the at least one DC link capacitor, to be pre-charged when the switching element of the main switch assembly located in the positive potential main line or when the switching elements of the main switch assembly located in both potential main lines are open.

[0046] The main switch assembly is used to switch the high-voltage electrical system, which may include, for example, at least one inverter, at least one air conditioning unit, and / or at least one DC charging unit. This means that by closing the main switch assembly, the system is connected to the high-voltage battery, particularly for supplying electrical power to the high-voltage electrical system via the high-voltage battery and / or for charging the high-voltage battery electrically, especially with DC charging. By opening the main switch assembly, the system is disconnected from the high-voltage battery. This main switch assembly is designed for high currents, particularly for driving and / or charging operations.

[0047] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0048] This shows: Fig. 1 schematically an embodiment of an on-board power supply arrangement for an electrically powered vehicle, Fig. 2 schematically shows another embodiment of an on-board power supply arrangement for an electrically powered vehicle, Fig. 3 schematically shows another embodiment of an on-board power supply arrangement for an electrically powered vehicle, and Fig. 4 schematically shows another embodiment of an on-board power supply arrangement for an electrically powered vehicle.

[0049] Corresponding parts are marked with the same reference symbols in all figures.

[0050] The Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows schematic representations of exemplary embodiments of a vehicle electrical system arrangement 1 for an electrically powered vehicle.

[0051] The electrical system 1 comprises a high-voltage battery 2 and a high-voltage electrical system 3. The high-voltage electrical system 3 comprises, in particular, high-voltage components 4 and at least one capacitor 5, in particular at least one intermediate circuit capacitor.

[0052] The on-board network arrangement 1 further comprises a low-voltage on-board network 6 with at least one or more low-voltage consumers and a low-voltage energy source 7.

[0053] The on-board network arrangement 1 also includes a bidirectional DC / DC converter 8, hereinafter referred to as the first DC / DC converter 8.

[0054] The high-voltage electrical system 3 and the high-voltage battery 2 are optionally connected or disconnected via a positive potential main line HV+ and a negative potential main line HV-, each with a switching element S+, S- of a main switch arrangement 10. A low-voltage side LV of the first DC / DC converter 8 is connected to the low-voltage electrical system 6 and the low-voltage power source 7.

[0055] A negative potential connection line AL- of the first DC / DC converter 8 is connected on one side to a high-voltage side HV of the first DC / DC converter 8 and on the other side to the high-voltage battery 2. In the illustrated embodiments, it is connected between the high-voltage battery 2 and the switching element S- of the main switch assembly 10, which is arranged in the negative potential main line HV-, and via this section of the negative potential main line HV- to the high-voltage battery 2.

[0056] A positive potential connection line AL+ of the first DC / DC converter 8, in which a disconnect switch TS (for example, a semiconductor switch) is arranged, is connected on one side to the high-voltage side HV of the first DC / DC converter 8 and on the other side to the high-voltage battery 2. In the illustrated embodiments, it is connected between the high-voltage battery 2 and the switching element S+ of the main switch arrangement 10, which is arranged in the positive potential main line HV+, to the positive potential main line HV+ and, via this section of the positive potential main line HV+, to the high-voltage battery 2. Thus, in the illustrated embodiments, the high-voltage side HV of the first DC / DC converter 8 is selectively connected to the high-voltage battery 2 via the positive potential connection line AL+, the disconnect switch TS, and the positive potential main line HV+, either when the disconnect switch TS is closed, or connectable when the disconnect switch TS is open.

[0057] A positive potential bypass line BL+ is provided to the switching element S+ of the main switch assembly 10, which is located in the positive potential main line HV+. A pre-charge switch VS+ is located in the positive potential bypass line BL+. The positive potential bypass line BL+ is connected on one side between the high-voltage side HV of the first DC / DC converter 8 and the disconnect switch TS to the positive potential connection line AL+ of the first DC / DC converter 8, and on the other side between the switching element S+ of the main switch assembly 10, which is located in the positive potential main line HV+, and the high-voltage electrical system 3 to the positive potential main line HV+.

[0058] In the embodiments according to the Fig. 1 and Fig. 3 is the low-voltage energy source mentioned above; 7 is a low-voltage battery; 9.

[0059] In the embodiments according to the Fig. 2 and Fig. 4 is the aforementioned low-voltage energy source 7, a low-voltage side LV of another DC / DC converter 11, hereinafter referred to as the second DC / DC converter 11. A high-voltage side HV of the second DC / DC converter 11 is connected to the high-voltage battery 2, as shown in the examples. Fig. 2 and Fig. 4, by connecting the high-voltage side HV of the second DC / DC converter 11 between the respective switching element S+, S- of the main switch arrangement 10 and the high-voltage battery 2 with the respective main potential line HV+, HV-.

[0060] In the embodiments according to the Fig. 1 and Fig. 2 the respective switching element S+, S- of the main switch arrangement 10 is designed as a contactor, or one switching element S+, S- of the main switch arrangement 10 is designed as a contactor and the other switching element S-, S+ of the main switch arrangement 10 is designed as a semiconductor switch.

[0061] In these embodiments according to the Fig. 1 and Fig. 2 For example, the pre-charging switch VS+ is designed as a relay or as a semiconductor switch.

[0062] In a method for operating the embodiment of the on-board power supply arrangement 1 according to the Fig. 1 and Fig. 2. For pre-charging the high-voltage on-board network 3, in particular the at least one capacitor 5, in particular the intermediate circuit capacitor, with the switching element S+ of the main switch arrangement 10 in the positive potential main line HV+ open and the disconnect switch TS open, the switching element S- of the main switch arrangement 10 in the negative potential main line HV- and the pre-charging switch VS+ are closed and a low-voltage voltage provided by the low-voltage energy source 7 is converted into a high-voltage voltage in the high-voltage on-board network 3 by the first DC / DC converter 8.

[0063] As soon as the high-voltage electrical system 3 reaches the voltage level of the high-voltage battery 2, the switching element S+ of the main switch arrangement 10 in the positive potential main line HV+ is closed, the disconnect switch TS is closed and the pre-charge switch VS+ is opened.

[0064] In the embodiments according to the Fig. 3 and Fig. 4 the main switch arrangement 10 is designed as a two-pole contactor.

[0065] In these embodiments according to the Fig. 3 and Fig. 4. An additional negative potential bypass line BL- is provided to the switching element S- of the main switch assembly 10, which is located in the negative potential main line HV. A further pre-charge switch VS- is located in this negative potential bypass line BL-. The negative potential bypass line BL- is connected on one side to the negative potential connection line AL of the first DC / DC converter 8 and on the other side between the switching element S- of the main switch assembly 10, which is located in the negative potential main line HV-, and the high-voltage electrical system 3, which is connected to the negative potential main line HV-.

[0066] In these embodiments according to the Fig. 3 and Fig. 4 For example, one pre-charge switch VS+, VS- is designed as a semiconductor switch and the other pre-charge switch VS-, VS+ is designed as a relay, or for example, the respective pre-charge switch VS+, VS- is designed as a relay.

[0067] In a method for operating the embodiment of the on-board power supply arrangement 1 according to the Fig. 3 and Fig. 4 To precharge the high-voltage on-board network 3, in particular the at least one capacitor 5, in particular the intermediate circuit capacitor, with the main switch arrangement 10 open and the disconnect switch TS open, the precharging switches VS+, VS- are closed and a low-voltage voltage provided by the low-voltage energy source 7 is converted into a high-voltage voltage in the high-voltage on-board network 3 by the first DC / DC converter 8.

[0068] As soon as the high-voltage electrical system 3 reaches the voltage level of the high-voltage battery 2, the main switch arrangement 10 is closed, the disconnect switch TS is closed and the pre-charge switches VS+, VS- are opened. Reference symbol list 1 On-board electrical system arrangement 2 high-voltage batteries 3 High-voltage electrical system 4 High-voltage components 5 Capacitor 6 Low-voltage electrical system 7 Low-voltage energy source 8 DC / DC converters, first DC / DC converter 9 Low-voltage battery 10 Main switch arrangement 11 additional DC / DC converters, second DC / DC converter AL+ positive potential connection cable AL negative potential connection line BL+ positive potential bypass line BL negative potential bypass line HV+ positive potential main line HV negative potential main line HV high-voltage side LV low-voltage side S+, S switching element TS disconnect switch VS+ pre-charge switch VS further pre-charge switch

Claims

[1] On-board electrical system arrangement (1) for an electrically powered vehicle, comprising a high-voltage battery (2), a high-voltage on-board electrical system (3), a low-voltage on-board electrical system (6), a low-voltage power source (7) and a bidirectional DC / DC converter (8), wherein the high-voltage on-board electrical system (3) and the high-voltage battery (2) can be selectively connected to or disconnected from each other via a positive potential main line (HV+) and a negative potential main line (HV-) with a switching element (S+, S-) of a main switch arrangement (10), and wherein a low-voltage side (LV) of the DC / DC converter (8) is connected to the low-voltage on-board electrical system (6) and the low-voltage power source (7), and wherein a negative potential connection line (AL-) of the DC / DC converter (8) is connected on one side to a high-voltage side (HV) of the DC / DC converter (8) and on the other side directly to the high-voltage battery (2), characterized by , that - a positive potential connection line (AL+) of the DC / DC converter (8), in which a disconnect switch (TS) is arranged, is connected on one side to the high-voltage side (HV) of the DC / DC converter (8) and on the other side directly to the high-voltage battery (2), and - a positive potential bypass line (BL+) is provided to the switching element (S+) of the main switch arrangement (10) arranged in the positive potential main line (HV+), wherein a pre-charge switch (VS+) is arranged in the positive potential bypass line (BL+), and wherein the positive potential bypass line (BL+) is connected on the one hand between the high-voltage side (HV) of the DC / DC converter (8) and the disconnect switch (TS) to the positive potential connection line (AL+) of the DC / DC converter (8) and on the other hand between the switching element (S+) of the main switch arrangement (10) and the high-voltage on-board network (3) to the positive potential main line (HV+). [2] On-board electrical system arrangement (1) according to claim 1, characterized by , that the low-voltage energy source (7) is a low-voltage battery (9) or a low-voltage side (LV) of another DC / DC converter (11), wherein a high-voltage side (HV) of the other DC / DC converter (11) is directly connected to the high-voltage battery (2). [3] On-board electrical system arrangement (1) according to one of the preceding claims, characterized by that the disconnect switch (TS) is designed as a semiconductor switch. [4] On-board electrical system arrangement (1) according to one of the preceding claims, characterized by , that - the respective switching element (S+, S-) of the main switch arrangement (10) is designed as a contactor, or - one switching element (S+, S-) of the main switch arrangement (10) is designed as a contactor and the other switching element (S-, S+) of the main switch arrangement (10) is designed as a semiconductor switch, and that the pre-charge switch (VS+) is designed as a relay or as a semiconductor switch. [5] On-board electrical system arrangement (1) according to any one of claims 1 to 3, characterized by , that the main switch arrangement (10) is designed as a two-pole contactor, wherein a negative potential bypass line (BL-) is provided to the switching element (S-) of the main switch arrangement (10) arranged in the negative potential main line (HV-), wherein a further pre-charge switch (VS-) is arranged in the negative potential bypass line (BL-), and wherein the negative potential bypass line (BL-) is connected on one side to the negative potential connection line (AL-) of the DC / DC converter (8) and on the other side is connected between the switching element (S-) of the main switch arrangement (10) arranged in the negative potential main line (HV-) and the high-voltage on-board network (3) to the negative potential main line (HV-). [6] On-board electrical system arrangement (1) according to claim 5, characterized by, that one pre-charge switch (VS+, VS-) is designed as a semiconductor switch and the other pre-charge switch (VS-, VS+) is designed as a relay, or that each pre-charge switch (VS+, VS-) is designed as a relay. [7] Method for operating an on-board power supply arrangement (1) according to one of claims 1 to 4, wherein, for pre-charging the high-voltage on-board power supply (3), with the switching element (S+) of the main switch arrangement (10) in the positive potential main line (HV+) open and the disconnect switch (TS) open, the switching element (S-) of the main switch arrangement (10) in the negative potential main line (HV-) and the pre-charging switch (VS+) are closed and a low-voltage voltage provided by the low-voltage energy source (7) is converted into a high-voltage voltage in the high-voltage on-board power supply (3) by the DC / DC converter (8). [8] Method according to claim 7, characterized by, that the switching element (S+) of the main switch arrangement (10) in the positive potential main line (HV+) is closed as soon as the high-voltage on-board network (3) reaches the voltage level of the high-voltage battery (2), and then the disconnect switch (TS) is closed and then the pre-charge switch (VS+) is opened. [9] Method for operating an on-board power supply arrangement (1) according to claim 5 or 6, wherein, for pre-charging the high-voltage on-board power supply (3) with the main switch arrangement (10) and the disconnect switch (TS) open, the pre-charging switches (VS+, VS-) are closed and a low-voltage voltage provided by the low-voltage energy source (7) is converted into a high-voltage voltage in the high-voltage on-board power supply (3) by the DC / DC converter (8). [10] Method according to claim 9, characterized by, that the main switch arrangement (10) is closed as soon as the high-voltage on-board network (3) reaches the voltage level of the high-voltage battery (2), and then the disconnect switch (TS) is closed and then the pre-charge switches (VS+, VS-) are opened.

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