DE202018001504U1 - Vehicle electrical system and vehicle - Google Patents

Abstract

Vehicle onboard network (BN) with a traction accumulator (TA), a traction sub-board network (TB1) and a second sub-board network (TB2), the traction sub-network (TB1) having an electric traction unit (M) and a traction inverter (TI) and the second Part-board network (TB2) has an AC charging unit (LE) connected to an AC charging terminal (LA) of the vehicle electrical system, and wherein the traction sub-board network (TB1) is electrically connected to the traction accumulator (TA) via a first switch (S1) and the second sub-board network ( TB2) via a second switch (S2) to the traction battery (TA) is electrically connected, wherein a control unit (SE) of the vehicle electrical system (BN) is drivingly connected to the switches (S1, S2) and is arranged in a traction or Rekuperationsmodus to provide the second switch (S2) in an open state, and in an AC charging mode, the first switch (S1) in an open th state.

Description

It is known to equip vehicles with an electric traction drive, which is powered by a battery. In order to feed back the energy taken from the accumulator during driving into the accumulator, vehicles can be provided with a charging connection, which can be connected to a stationary voltage source (a charging station).

Furthermore, it is known that aging of the electrical and electronic components leads in particular to high-voltage applications. Therefore, in the design of components in a vehicle electrical system, the lifetimes of the components are taken into account in the design of the vehicle electrical system. If the lifetime is exceeded, errors may occur in the affected components that cause the vehicle to remain idle. It is now an object to provide a way to increase the availability of a vehicle.

This object is achieved by the vehicle electrical system and the vehicle according to the independent claims. Further embodiments, features and advantages will become apparent from the dependent claims, the description and the figures.

Aging of components can be avoided or reduced by disconnecting at least one part-board network whose function is not currently used. As a result, the components within the electrical system receive no voltage, so that the aging is reduced. Since there is no supply voltage to a component which is in a separate onboard electrical system, there is a further reduction in aging. By separating subnets, i. by interrupting the power supply, unlike the mere deactivation of a component, the lifetime can be increased because aging is avoided in the deactivated but energized state.

A vehicle electrical system is proposed which has a traction accumulator, a first sub-board network (also referred to as a "traction sub-board network") and at least one second (i.e., further) sub-board network. The vehicle electrical system is in particular a high-voltage on-board electrical system and also the traction battery is preferably a high-voltage battery. Nominal voltages of more than 60 V and in particular of at least 120 V, 200 V, 300 V, 350 V or 380 V are associated with the prefix "high-voltage", in particular of at least 600 V or 750 V. As vehicles (for accommodating the vehicle electrical system) Especially motor vehicles with electric drive into consideration, which can be loaded conductively from the outside, ie Plug-in hybrid vehicles or electric vehicles.

The first sub-board network has an electric traction unit and a traction inverter. The traction unit comprises an electric machine, in particular a (permanently excited or externally or self-excited) synchronous machine or an asynchronous machine. The traction inverter is connected between the traction unit and the traction accumulator and is preferably configured to be powered by the traction accumulator and to generate phase currents for the traction unit that result in a rotating field in the electric machine. The traction inverter can be bidirectional and thus also suitable for recuperation of energy for feeding back into the traction accumulator.

The second (further) sub-board network has an AC charging unit. This is connected between an AC charging port of the vehicle electrical system and the Traktionsakkumulator. Energy can be transmitted from the external AC power supply network to the traction battery via the AC charging unit, in particular via the AC charging terminal to which the AC charging unit is connected.

The second sub-board network and in particular the alternating-voltage charging unit are preferably set up for galvanically connected charging. Here, in particular via the AC charging connection, the external AC power supply network at least one potential of the supply network (via at least one switch) conductively connected to the Traktionsakkumulator. Alternatively, the further sub-board network and in particular the alternating-voltage charging unit are set up for galvanically isolated charging. In this case, the external AC power supply or AC charging port is electrically isolated connected to the Traktionsakkumulator, such as a transformer with at least two galvanically isolated windings.

It is a first switch (which can be referred to as a subnet connection switch) is provided, with which at least a part of the electrical system and thus the components of the at least one sub-board can be separated from the (further) sub-board required for loading. As a result, the supply voltage to the inverter can be turned off when charging, and it can be turned off the supply voltage to the charging unit when the traction is active. It is an aging of components avoided by applying the supply voltage (especially in the deactivated mode), such as components of the Traction sub-board network by the "other" Teilbordnetze (such as equipped with the traction unit sub-board network) are separated from the required for loading sub-board network.

In particular, with the first switch, the traction sub-network can be disconnected from the traction accumulator (and thus from the other sub-net for charging) when charging.

The traction sub-board network is therefore electrically connected via the first switch to the traction battery. By opening the first switch, the traction sub-board network can thus be separated from the traction accumulator and thus from the further sub-board network. In particular components of the traction sub-board network can be separated from the second sub-board network in order to achieve a lower aging of components of the first sub-network during charging. The second sub-board network is electrically connected to the Traktionsakkumulator. Since the first sub-board network is connected to the accumulator via the first switch, the components of the traction sub-board network are separated from the second sub-board network by disconnecting the first sub-board network. The second sub-board network can also be referred to as (AC) charging sub-board network. The second part of the electrical system can also have other components in addition to the charging unit.

The electrical system can be provided with a control unit. This is drivingly connected to the switches. The control unit may be configured to operate in a traction mode in which the motor vehicle is driven and in a charging mode in which a traction accumulator of the motor vehicle is charged. The control unit is preferably set up to provide the first switch in a closed state in traction mode and to provide it in an open state in the charging mode. Preferably, the control unit is set up to open the first switch before starting the charging mode, or to suppress activation of the charging unit until the first switch is opened.

Further, the control unit may be configured to close the first switch before the beginning of the traction mode and is configured to suppress activation of the traction unit and / or the inverter until the first switch is closed. By opening the first switch, only the components of the second sub-electrical system are charged with the voltage of the battery while the components of the traction sub-electrical system is disconnected. In charging mode, therefore, only at the component of the second sub-electrical system (i.e., at the AC charging unit) is a (high-voltage) voltage applied, so that only this one ages.

The vehicle electrical system is thus equipped with the traction battery, the traction sub-board network (first sub-board network) and the second sub-board network. The second subnetwork has an AC charging unit. This is connected to an AC charging connection of the vehicle electrical system. The AC charging unit is a conductive (i.e., line-tied) charging unit.

The control unit is drivingly connected to the switches and is arranged to provide all the switches in an open state which lie between the accumulator and a sub-board network in which only (in the given mode) inactive components are located. For example, the charging unit of the second sub-electrical system is inactive in traction mode. Furthermore, in particular the traction inverter of the first sub-electrical system is inactive in the charging mode.

The control unit is therefore configured to provide the second switch in an open state in a traction or recuperation mode. The first switch is closed. In an AC charging mode, the control unit provides the first switch in an open state. The second switch is closed. Since the control unit is connected to the switches driving, the control unit is set to adjust these switching states. The traction mode can also be regarded as a traction or recuperation mode, since power also flows through the traction inverter (then bidirectionally) in the recuperation and thus the same switching states apply as for the traction.

The AC charging unit may be configured for three-phase AC charging, i. for connection to a three-phase network. However, the AC charging unit may also be designed for single-phase AC charging.

The vehicle electrical system may further comprise a third sub-electrical system. This is equipped with a DC charging unit. The third sub-board network is connected to the traction battery via a third switch. The control unit is connected to the first, second and third switches. The control unit is configured to provide the third switch in a closed state in a DC charging mode. The control unit is set up to provide the first and the second switch in an opened state in this mode. In the DC charging mode current between a DC charging terminal of the vehicle electrical system (in particular the third sub-electrical system) and the Transfer Traktionsakkumulator via a DC charger. The controller may be drivingly connected to the DC charger and configured to control current flow through the DC charger in the DC charge mode. The DC charging unit can be designed as a two-pole DC charging, ie for connection to a DC voltage network. The DC charging terminal and the AC charging terminal may be provided as contacts of the same connector. The DC charger may be bidirectional, such as for feeding back via the DC charging port. Similarly, the AC charger may be bidirectional, such as for feeding back via the AC charging terminal. The control unit may be designed to control the feeding back or charging via the relevant charger. The features shown here for charging also apply to the feeding back, in particular with regard to the switching states of the relevant switch.

The second sub-board network may comprise a tempering device. In this case, the control unit is set up to provide the second switch in an open state in an external tempering mode. As a result, the second sub-board network is separated from the rest of the electrical system. Furthermore, in the external temperature control mode, the control unit can be set up to also provide the first switch and optionally also other switches which disconnect sub-bus systems in an open state, for example third, fourth, fifth and / or sixth switches as mentioned below. In the external tempering mode, the tempering device is supplied via the AC charging terminal and the AC charging unit, i. from an external source of energy. The prefix "external" here denotes the position of the energy source relative to the vehicle electrical system. The temperature control device may be an electrical heater (an interior, a vehicle component such as the tank or the accumulator or an exhaust gas catalyst) or an electric air conditioning compressor. The tempering device is designed for conditioning the vehicle.

The vehicle on-board network may also have (in combination or alternatively to the third sub-board network) a fourth sub-board network. The fourth subnetwork is equipped with an inductive charging unit. The inductive charging unit can thus have a coil and a passive or active converter connected thereto, optionally also a voltage converter. The fourth sub-board network is connected via a fourth switch to the traction battery (electrically). The control unit is connected to the first, second and fourth switches. The control unit is set up to provide the fourth switch in a closed state in an inductive charging mode. Furthermore, the control unit is set up to provide the first and the second switch in an opened state. This also applies to the third switch (or also to a fifth and / or sixth switch as indicated below), if present. In the inductive charging mode, current is transmitted via the inductive charging unit, in particular to the traction battery (or also from this path for the return feed). By the open switch, the operating voltage (in particular of the accumulator) is separated from the respective sub-board networks. As a result, no supply voltage is applied to the components there (in particular if they are inactive anyway). This protects the life of the thus separated components.

The vehicle on-board network can (alternatively or in combination with the third, the fourth or the third and the fourth sub-board network) have a fifth sub-board network. In the fifth subnetwork, an electric heating unit is provided. Alternatively, there may be provided a (further or alternatively placed) electric air conditioning compressor. The fifth sub-board network is electrically connected via a fifth switch to the traction battery. The control unit is drivingly connected to the fifth switch, in particular also to the first and second switch, preferably also to the third and / or fourth switch, if present. The control unit is set up to provide the fifth switch in a closed state in an internal temperature control mode. The control unit is in particular configured to provide in this mode the first and the second switch, optionally also the third and / or fourth switch in an opened state. In the internal temperature control mode, the heating unit is supplied by the traction accumulator via the fifth switch. Since the energy source is located inside the vehicle electrical system, this mode receives the prefix "Internal". Even with the use of an internal voltage source, only the heating unit in the fifth sub-electrical system is supplied with a supply voltage and thus with aging. Preferably, the remaining sub-network are (if not active) separated via the switch of the Traktionsakkumulator or from the supply voltage, so that they do not age by the applied voltage (in the inactive state). The heating unit may include a heating unit of the interior, i. the air conditioning system, or another vehicle component, in particular an exhaust gas catalyst or the accumulator. Instead of or in combination with the heating unit, an electric air conditioning compressor may also be provided.

The switches can be designed as a single pole. These are in particular only in a positive DC power supply rail connected in series. Alternatively, the switches are bipolar. In this case, the switches are connected in series, in particular in the positive DC voltage supply rail as well as in a negative DC voltage supply rail.

The DC charging terminal may be connected to ends of windings of the traction unit that are opposite to ends of the windings connected to the traction inverter. As a result, direct current can be conducted from the DC charging connection through at least one winding of the traction unit to the inverter and from there to the accumulator. The connection between the DC charging terminal and the traction unit may include a switch. Alternatively, instead of the DC charging terminal, the AC charging terminal may be configured or connected or switched. This is connected to the charging unit of the other electrical system, in particular directly or via a switchable separating device. The charging unit of the second sub-electrical system can be directly connected to the Traktionsakkumulator, can be connected via a switchable separator with this, and / or can be connected via a matching DC-DC converter with this.

In the second part of the electrical system can be provided an inverter, which is connected to a power outlet. This also receives no supply voltage when the second switch is open. Without supply voltage, the inverter will not age (even if it is inactive) due to voltage.

In a sixth sub-board network, a further traction unit (with an electric machine) and a traction inverter may be provided. This subnetwork can be considered as an auxiliary traction subnetwork. This additional traction unit and the initially mentioned traction unit may be provided on different axles of the vehicle. The sixth sub-board network is connected via a sixth switch to the traction battery. The control unit is drivingly connected to this switch. The control unit is configured to provide the sixth switch in a closed state in an auxiliary traction mode. In one of the charging modes, the control unit drives the sixth switch in an open state. This also applies to the internal heating mode (or the internal temperature control mode). As a result, the inverter of the sixth sub-electrical system is only supplied with a supply voltage when the additional traction mode is present.

The traction sub-network (i.e., the first sub-board network) may include a first diverting capacitor. The second sub-board network may have a second bypass capacitor. Also the sixth sub-board network, i. the auxiliary sub-board network may include a bypass capacitor. The bypass capacitors connect a supply voltage potential to a reference potential, such as ground, to dissipate and thereby attenuate AC voltage components to the supply voltage potential.

Further, a refrigeration cycle of a vehicle will be described. The cooling circuit is equipped with a heat sink (WS) and at least a first and a second cooling circuit section. The first cooling circuit section is connected to the heat sink via a first valve and is thermally connected to an electric traction unit of the vehicle and / or to a traction inverter, in particular to the (first) traction unit and / or to the (first) traction inverter of the vehicle electrical system described here.

The second cooling circuit section is connected via a second valve to the heat sink and thermally connected to an AC charging unit, in particular to the AC charging unit of the vehicle electrical system described here. A control unit, in particular the control unit of the vehicle electrical system described here, is drivingly connected to the valves. Control unit is arranged to provide the second valve in a blocking state in a traction or recuperation mode (in particular in the traction or recuperation mode described here). The control unit is further configured to provide the first valve in a blocking state in an AC charging mode (in particular in the AC charging mode described here).

This reduces the aging of components that are inactive because it does not receive thermal stress from the heat of other, active components of the same cooling circuit.

The cooling circuit may have a third cooling circuit section, which is connected via a third valve to the heat sink and thermally connected to a DC charging unit (in particular the DC charging unit of the vehicle electrical system described here). The control unit (in particular of the vehicle electrical system) is drivingly connected to the third valve and is arranged to provide the third valve in a closed state in a DC charging mode (in particular in the DC charging mode mentioned in the introduction). In the DC charging mode, power is supplied between a DC charging terminal and the traction battery via a DC charger transfer. This relates in particular to the aforementioned components of the same name.

The second cooling circuit section may also be thermally connected to a tempering device of the vehicle electrical system, in particular to a tempering device, as described above. The control unit is set up to provide the second valve (S2) in a connecting state in an external temperature control mode (in particular in the external temperature control mode mentioned above). In the external tempering mode, the tempering device is powered by the AC charging terminal and the AC charging unit.

The cooling circuit may include a fourth cooling circuit section connected to the heat sink via a fourth valve. The fourth cooling circuit section is thermally connected to an inductive charging unit, in particular to the initially mentioned inductive charging unit of the vehicle electrical system. The control unit (in particular, that of the vehicle electrical system) is drivingly connected to the fourth valve and is arranged to provide the fourth valve in a connecting state in an inductive charging mode (in particular in the aforementioned inductive charging mode), and the first and the second Provide valve in a blocking state. In the inductive charging mode, power is transmitted via an inductive charging unit (for instance via the inductive charging unit of the vehicle electrical system mentioned at the outset).

The cooling circuit may have a fifth cooling circuit section, which is connected via a fifth valve with the heat sink and thermally connected to a heating unit (in particular the heating unit of the vehicle electrical system mentioned above) is connected. The control unit is drivingly connected to the fifth valve and is arranged to provide the fifth valve in a connecting state in an internal tempering mode (in particular in the aforementioned internal tempering mode) and to provide the first and the second valve in a blocking state. In the internal temperature control mode, the heating unit is active and is supplied in particular by the traction battery.

In addition, a vehicle is described, which is equipped with the vehicle electrical system described here and a cooling circuit, in particular with the cooling circuit mentioned above. The vehicle has a cooling circuit with a heat sink and at least a first and a second cooling circuit section. The first cooling circuit section is connected to the heat sink via a first valve and is thermally connected to the electric traction unit and / or to the traction inverter. The second cooling circuit section is connected to the heat sink via a second valve and thermally connected to the AC charging unit. The control unit of the vehicle electrical system is drivingly connected to the valves and is configured to provide the second valve in a locked state (and to provide the first valve in a connecting state) in the traction or recuperation mode, and is further configured to be the first in the AC charging mode Provide valve in a blocking state (and to provide the second valve in a connecting state). In the traction or recuperation mode, power is transferred via the AC charger.

The cooling circuit of the vehicle may include a third cooling circuit section, which is connected via a third valve to the heat sink and is thermally connected to a DC charging unit of the vehicle electrical system. The control unit of the vehicle electrical system is drivingly connected to the third valve and is arranged, in a DC charging mode, to provide the third valve in a closed state. In the DC charging mode, power is transferred between a DC charging terminal and the traction battery via a DC charger.

It can be provided that the second cooling circuit section of the cooling circuit of the vehicle is also thermally connected to a tempering device of the vehicle electrical system. The control unit is set up to provide the second valve in a connecting state in an external tempering mode. In the external tempering mode, the tempering device is powered by the AC charging terminal and the AC charging unit.

The cooling circuit of the vehicle may have a fourth cooling circuit section, which is connected via a fourth valve to the heat sink (WS) and is thermally connected to an inductive charging unit of the vehicle electrical system. The control unit of the vehicle electrical system is drivingly connected to the fourth valve. The control unit is configured to provide the fourth valve in a connecting state in an inductive charging mode, and to provide the first and the second valve in a blocking state. In the inductive charging mode, power is transmitted via an inductive charging unit of the vehicle electrical system.

• Die 1 zeigt eine symbolhafte Übersicht zur näheren Erläuterung des Bordnetzes.
• Die 2 zeigt eine Darstellung zur Erläuterung eines Kühlkreislaufs eines Fahrzeugs.

The cooling circuit of the vehicle may include a fifth cooling circuit section, which is connected via a fifth valve to the heat sink and is thermally connected to a heating unit of the vehicle electrical system. The control unit of the Vehicle electrical system is drivingly connected to the fifth valve and is arranged to provide the fifth valve in a connecting state in an internal tempering mode, and to provide the first and the second valve in a blocking state. In the internal tempering mode, the heating unit is powered by the traction battery.

• The 1 shows a symbolic overview for a more detailed explanation of the electrical system.
• The 2 shows a diagram for explaining a cooling circuit of a vehicle.

In the 1 An on-board network BN of a vehicle is shown, which has an interface IF with an AC power grid VN connected is. Furthermore, the electrical system BN over the interface IF , in particular via the DC charging port, be connected to an optional DC power supply network VNDC. Furthermore, the electrical system BN via an inductive charging unit IL that are at the interface IF is loaded from the outside. The interface is formed from the side of the supply network of at least one charging plug, in particular of corresponding contacts K , For the inductive charging unit can be provided on the side of the supply network, a charging coil as a complementary element to the inductive charging unit IL of the electrical system BN , Only single contact symbols are shown symbolically for the wired connections. From the side of the electrical system BN becomes the interface IF made of AC charging connection LA , from DC charging connection LA ' and the inductive charging unit IL ,

There is a first sub-board network TB1 that also traction subpanel network TB1 is called, as well as a second sub-board network TB2 , which also serves as a further subnetwork TB2 referred to as. The AC charging port LA is to the second sub-board network TB2 connected.

The traction subnetwork TB1 includes an electric traction unit M (ie, an electric machine) and an inverter TI who is the traction unit M with a first switch S1 combines. About the first switch S1 is the traction subnetwork TB1 with a traction accumulator TA of the electrical system BN connected. Opening this switch separates the first sub-board network TB1 from the second sub-board network TB2 (and thus from the AC charger). Further, the first switch in the open state separates the first sub-board network from the traction battery TA from. The separation of the respective sub-board network by the relevant switch can be unipolar and (only) relate to a (single) supply potential. The switch (s) may therefore be single-pole, such as switches provided in the positive supply potential rail, while a negative supply potential rail or ground rail does not include the switches. Alternatively, the switches are bipolar and affect both positive and negative (or ground) potential.

Is the first switch S1 opened (and S2 closed), then lies the voltage of the accumulator TA only on the loading unit LE at. During charging, therefore, only the charging unit LE and not the traction inverter age due to voltage. The first switch S1 is open during the charging mode. This also applies to S3, S4, S5 and S6 (if present). The first switch S1 is closed during traction mode, leaving the traction unit M can be supplied, the second switch S2 is open. Is the second switch S2 opened, the voltage of the accumulator lies TA not at the loading unit LE at. This protects it from aging in this mode.

The presentation of the 1 also serves to describe additional optional components in the second sub-board network TB2 , There are examples of a tempering device TV and a DC-DC converter unit GW shown. These also age when voltage is applied, even without being activated (ie in "idle" mode). In an external tempering mode is the switch S2 open. Is an auxiliary switch between the AC charging port LA and the loading unit LE is provided, this is closed in the external Temperierungsmodus. In the external tempering mode, the tempering device TV via the AC charging port LA externally powered. There S2 is open, there are no components outside the sub-board network TB2 thereby put under tension, so that in the external Temperierungsmodus no other components than those of the second sub-electrical system TB2 Are subject to aging. The other switches ( S3 . S4 . S5 . S6 ) are preferably open. The tempering device TV may comprise an electric heater, which is designed approximately as a PTC element, or may comprise an electric air conditioning unit or both. The tempering device TV especially affects the interior. The tempering device TV may have a heat-conducting channel leading to the interior of the vehicle and may be separated from a cooling channel. The tempering device TV can be formed by a PTC heating element. With the tempering device TV The interior of the vehicle can be conditioned, in particular before the start of the journey. The energy required for this purpose is supplied from the outside via a charging connection ( LA or LA ' or IL ), in particular via a path via which energy from the outside is also supplied to the traction accumulator. is S2 closed (and S1 open), then energy can be used to condition and charge the accumulator TA be supplied from the outside, in particular via the same connection. The external tempering mode can be performed during the charging mode. The tempering device TV and in particular at least one connection of the voltage supply of this device can via a conditioning switch with the second switch or with the charging unit LE be connected. As a result, if the external temperature control mode is not provided, however, the second sub-electrical system TB2 is under tension, the tempering device TV from remaining subnetwork TB2 be separated in terms of power supply.

The second sub-board network may further comprise a voltage converter or a voltage converter GW exhibit. This can also be connected via an additional switch with the remaining second electrical system. The reference number GW may designate a DC-DC converter that generates a different DC voltage, about 12 V, 24 V, 48 V or 5 V from a DC voltage in the second electrical system. The auxiliary switch is only closed when the DC-DC converter is active. As a result, aging is avoided by voltage applied in the inactive state of the converter. The converter GW can also be connected directly (switchless) with the remaining second sub-board network.

A third sub-board network TB3 is via a third switch S3 with the accumulator TA connected. The third sub-board network TB3 includes a DC charging unit LE ' set up for DC charging the traction inverter TA , The DC charging unit LE ' is in particular a DC-DC converter. This also ages in an inactive state if a high voltage is permanently applied to one side of the converter. Therefore, the third switch S3 be open when no DC charging mode exists. If the DC charging mode is present, S3 is closed, so that a DC charging connection LA ' the loading unit LE 'can be supplied to the accumulator TA invites. The charging terminals referred to herein are preferably charging sockets, which may be designed according to a charging standard for electric vehicles or plug-in vehicles. Also the inductive charging unit IL the fourth sub-electrical system is accessible from the outside (ie without opening the interior or the engine compartment of the vehicle).

A fourth subnetwork TB4 includes the inductive charging unit IL , which may include a power converter in addition to a coil. Is the fourth switch S4 , which is the inductive charging unit IL with the traction accumulator TA connects, open, then is the inductive charging unit IL and in particular their power supply is not live. Is the inductive charging unit IL inactive (ie there is no inductive charging mode), then the switch S4 opened, the inductive charging unit IL is not under tension and it results in the inactive case no aging by applied high-voltage.

A fifth subnetwork TB5 is via a fifth switch S5 with the accumulator TA connected. The fifth subnetwork TB5 includes an electric heating unit EH and / or an electric air conditioning compressor. The component (s) of the fifth sub-electrical system TB5 are active in an internal temperature control mode in which the interior or other component of the vehicle (such as an exhaust catalyst or the traction battery TA ) is heated or cooled, especially while driving. The energy for this is taken from the accumulator. If there is no internal tempering mode, the fifth switch is S5 open and the onboard network TB5 or its components are not under tension, so that there is no aging due to voltage applied in inactive operation.

A sixth sub-board network TB6 , which is a second or further traction sub-board network, comprises a traction unit M ' , and a traction inverter TI ' , A sixth switch S6 connects this sixth sub-board network TB3 with the traction accumulator.

In (additional) traction mode is the sixth switch S6 closed (so that the sub-board network TB6 with the traction accumulator TA connected is). In charge mode is the sixth switch S6 open, so that the sixth sub-board network TB6 separated (and thus potential-free) is.

In one embodiment, the sub-networks are TB3 - 6 and their associated switches S3 - S6 optional.

A control unit SE is driving with the switches S1 - S6 (and possibly with the other, here mentioned switches) drivingly connected, as symbolically represented by the arrows. The second subnetwork TB2 is by means of the switch S2 with the traction accumulator TA (or with the traction sub-board network TB1 ) electrically connected and thus separated from this.

The DC charging port LA ' serves to connect the vehicle electrical system BN to a DC power supply VNDC. The DC charging port LA ' can be part of the third sub-board network TB3 be. The DC charging unit is optional and may not be provided, with about a component connected to the accumulator TA is downstream, or the charging station are designed for power control and, if necessary, for voltage adjustment. This allows a power path for (additional) DC charging.

One possibility is the DC charging connection LA ' via an optional switch with one end of at least one winding of the traction unit M to connect, which is opposite to that end of the at least one winding connected to the traction inverter TI connected. This will cause the DC charging through the traction unit M possible through; the traction inverter TI or its power semiconductors can be used to control the charging and the at least one winding can be used as the inductance of a DC-DC converter, the at least one power switch of the traction inverter TI includes, which forms the DC-DC converter together with the inductance. Instead of the connection LA ' can the connection LA be connected at this point (for AC charging via the electrical machine and its inverter, which then together form a controllable power converter).

Apart from the connection between the AC charger LE and the AC charging port LA , which may be approximately single-phase or three-phase, all connections are preferably bipolar, ie comprise a plus and a minus rail. The mentioned switches (in particular those with the reference numerals S1 - S6 ) are therefore bipolar, ie connect or open both in the plus rail and in the negative rail.

after the 1 which represents connections of components in electrical regard, is the 2 a representation of thermal compounds of components already in 1 are shown.

In the 2 is a cooling circuit KK shown, which is a heat sink WS and heat sources, which is connected via a valve to the heat sink. The presented topology should show which components are connected, is by no means binding and should not determine how the components are connected. In the 2 illustrated bus topology as a connection between the topologies is purely exemplary; Ring topologies or mixed topologies are also conceivable. In particular, the heat sink may be connected to a ring to which the heat sources are connected via respective valves.

The cooling circuit has various sections (cooling circuit sections A1 - A5 ) to which heat sources are connected. To the first section A1 are heat sources in the form of the drive unit M and the associated traction inverter TI thermally connected. The first paragraph A1 is over a valve V1 to the heat sink WS connected. To the second section A2 is a heat source in the form of the AC voltage charging unit LE thermally connected. The second section A2 is over a valve V2 to the heat sink WS connected. To the third section A3 is a heat source in the form of the DC voltage charging unit LE 'thermally connected. The third section A3 is over a valve V3 to the heat sink WS connected. To the fourth section A4 is a heat source in the form of the inductive charging unit LE (Especially in the form of a power converter of this charging unit) thermally connected. The fourth section A4 is over a valve V4 to the heat sink WS connected. To the fifth section A5 is a heat source in the form of the electric heating unit EH thermally connected. The fifth section A5 is via a valve V5 to the heat sink WS connected. Instead of the electric heating unit, which is electrically from the accumulator TA is operated, can also be the tempering device TV be provided for the temperature control by means of external energy sources in this section. The valves permit thermal, controllable separation from the remainder of the cooling circuit so that components that are inactive do not receive thermal stress from other active components when the inactive component in question is disconnected by the valve of interest.

To the cooling circuit can thermally also the accumulator TA be connected, preferably via its own valve. As a result, the accumulator can be tempered, for example in cold days by preheating by means of the component TV or EH , The valves which lead to those portions to which these components are thermally connected are then in a conducting state, while the other valves remain blocking. This can cause heat between the component TV or EH on the one hand and the Traktionsakkumulator on the other hand be replaced. Instead of Traktionsakkumulators so an internal combustion engine can be preheated targeted. Another cooling circuit is formed as shown, but without heat sink. The heat sink is in particular a radiator.

Claims (11)

Vehicle onboard network (BN) with a traction accumulator (TA), a traction sub-board network (TB1) and a second sub-board network (TB2), wherein the traction sub-network (TB1) has an electric traction unit (M) and a traction inverter (TI) and the second Part-board network (TB2) has an AC charging unit (LE) connected to an AC charging terminal (LA) of the vehicle electrical system, and wherein the traction sub-board network (TB1) is electrically connected to the traction accumulator (TA) via a first switch (S1) and the second sub-board network ( TB2) via a second switch (S2) with the Traktionsakkumulator (TA) is electrically connected, wherein a control unit (SE) of the vehicle electrical system (BN) is drivingly connected to the switches (S1, S2) and is arranged, in a traction or Rekuperationsmodus the second switch (S2) in an open state and to provide the first switch (S1) in an open state in an AC charging mode. Vehicle electrical system (BN) to Claim 1 , which further comprises a third sub-board network (TB3) equipped with a DC charging unit (LE '), the third sub-board network (TB3) being electrically connected to the traction battery (TA) via a third switch (S3), the control unit ( SE) is drivingly connected to the first, second and third switches (S1, S2, S3) and arranged to operate in a DC charging mode in which power is supplied between a DC charging terminal (LA ') and the traction accumulator (TA) via a DC charging device (LE'; ), to provide the third switch (S3) in a closed state, and to provide the first and second switches (S1, S2) in an opened state. Vehicle electrical system (BN) according to one of the preceding claims, wherein the second sub-electrical system (TB2) comprises a temperature control device (TV), wherein the control unit (SE) is set up, in an external temperature control mode, in which the temperature control device (TV) via the AC charging connection ( LA) and the AC charging unit (LE) is supplied to provide the second switch (S2) in an open state. Vehicle electrical system (BN) according to one of the preceding claims, further comprising a fourth sub-board network (TB4) equipped with an inductive charging unit (IL), the fourth sub-board network (TB4) via a fourth switch (S4) with the Traktionsakkumulator (TA ) is electrically connected, wherein the control unit (SE) with the first, second and fourth switches (S1, S2, S4) is drivingly connected and is arranged, in an inductive charging mode in which power via the inductive charging unit (IL) transmitted is to provide the fourth switch (S4) in a closed state, and to provide the first and the second switch (S1, S2) in an open state. Vehicle electrical system (BN) according to one of the preceding claims, further comprising a fifth sub-board network (TB5), which is equipped with an electric heating unit (EH), the fifth sub-board network (TB5) via a fifth switch (S5) with the Traktionsakkumulator (TA is electrically connected, wherein the control unit (SE) with the first, second and fifth switches (S1, S2, S4) is drivingly connected and is set, in an internal tempering mode in which the heating unit (EH) via the fifth switch (S5) is supplied from the traction battery (TA) to provide the fifth switch (S5) in a closed state, and to provide the first and second switches (S1, S2) in an opened state. Vehicle electrical system (BN) according to one of the preceding claims, wherein the switches (S1, S2) are single-pole and are connected in series only in a positive DC supply rail, or the switches (S1, S2) are bipolar and in both the positive DC supply rail and in a negative DC supply rail are connected in series. Vehicle with a vehicle electrical system (BN) according to one of the preceding claims, wherein the vehicle further comprises: - A cooling circuit (KK) with a heat sink (WS) and at least a first and a second cooling circuit section (A1, A2), wherein the first cooling circuit section (A1) via a first valve (V1) to the heat sink (WS) is connected and thermally connected to the electric traction unit (M) and / or to the traction inverter (TI); and the second cooling circuit section (A2) is connected to the heat sink (WS) via a second valve (V2) and thermally connected to the AC charging unit (LA); wherein the control unit (SE) of the vehicle electrical system is drivingly connected to the valves (S1, S2) and is arranged to provide the second valve (V2) in a locked state in the traction or recuperation mode, and in the AC charging mode the first valve (S1 ) in a blocking state. Vehicle after Claim 7 wherein the cooling circuit (KK) comprises a third cooling circuit section (A3) connected to the heat sink (WS) via a third valve (V3) and thermally connected to a DC charging unit (LE ') of the vehicle electrical system (BN); Control unit (SE) of the vehicle electrical system is drivingly connected to the third valve (S3) and is arranged, in a DC charging mode, in which current between a DC charging terminal (LA ') and the Traktionsakkumulator (TA) via a DC charger (LE') is transmitted, to provide the third valve (V3) in a closed state. Vehicle after Claim 7 or 8th wherein the second cooling circuit section (A2) is further thermally connected to a temperature control device (TV) of the vehicle electrical system (BN), wherein the control unit (SE) is set up, in an external temperature control mode in which Temperierungsvorrichtung (TV) via the AC charging terminal (LA) and the AC charging unit (LE) is supplied to provide the second valve (V2) in a connecting state. Vehicle after Claim 7 . 8th or 9 wherein the cooling circuit (KK) comprises a fourth cooling circuit section (A4) which is connected via a fourth valve (V4) to the heat sink (WS) and thermally connected to an inductive charging unit (IL) of the vehicle electrical system (BN), wherein the Control unit (SE) of the vehicle electrical system (BN) drivingly connected to the fourth valve (V4) is connected and is arranged, in an inductive charging mode in which power is transmitted via an inductive charging unit (IL) of the vehicle electrical system (FB), the fourth valve (V4) to provide in a connecting state, and to provide the first and the second valve (V1, V2) in a locking state. Vehicle after one of the Claims 7 - 10 wherein the cooling circuit (KK) comprises a fifth cooling circuit section (A5) which is connected via a fifth valve (V5) to the heat sink (WS) and is thermally connected to a heating unit (EH) of the vehicle electrical system (BN), wherein the control unit (SE) of the vehicle electrical system (BN) is connected to the fifth valve (V5) and is set to operate in an internal temperature control mode, in which the heating unit (EH) is supplied by the traction battery (TA), the fifth valve (V5) to provide in a connecting state, and to provide the first and the second valve (V1, V2) in a locking state.

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