WO2019170730A1

WO2019170730A1 - Method for transferring electrical power to an electrical energy accumulator of a vehicle on-board system and vehicle on-board system

Info

Publication number: WO2019170730A1
Application number: PCT/EP2019/055542
Authority: WO
Inventors: Franz Pfeilschifter; Martin GÖTZENBERGER
Original assignee: Cpt Group Gmbh
Priority date: 2018-03-08
Filing date: 2019-03-06
Publication date: 2019-09-12
Also published as: CN112041193B; CN112041193A; DE102018203514A1

Abstract

The invention relates to a method for transferring electrical power to an electrical energy accumulator (ES) of a vehicle on-board system (BN), in which method, in an alternating-current direct-charging mode, the power is transferred from a rectifier (GR) of the vehicle on-board system (BN), which is supplied by an alternating-current charging connection (ACLB), directly to the energy accumulator (ES) of the vehicle on-board system (ES). In an alternating-current adaptation charging mode, the power is transferred from the rectifier (GR) via an inverter (I) and from the inverter (I) via an electric machine (EM) to the energy accumulator (ES). The invention further relates to a vehicle on-board system (BN) for carrying out the method.

Description

description

A method for transmitting electrical power to an electrical energy storage of a vehicle electrical system and vehicle electrical system

Motor vehicles with electric drive have one

electrical energy storage in the form of a Traktionsakkumu lators, which feeds the electric drive. In order to charge the energy storage, a charging connection is attached to such a motor vehicle. An external energy source can be connected via this charging connection.

In order to control the charging of the energy storage, a power electronics is housed in the motor vehicle. Since this is designed for high power of more than 10 kW or even more than 100 kW and also has to cope with different and each variegated voltage levels at the charging port and the energy giespeicher, resulting in significant costs for the power electronics.

It is therefore an object of the invention to provide a way by which electrical power can be transmitted to the energy storage of the vehicle electrical system with less effort.

This object is solved by the subject matters of the independent claims. Further embodiments, features and advantages will become apparent from the dependent claims, the description and the figure.

It is proposed to provide a rectifier, which is connected to the AC charging port for transmitting AC power between an AC charging port and an energy storage of a vehicle electrical system. Depending on the voltage levels on the DC side of the rectifier and on the energy storage, either the power delivered by the rectifier is directly (in particular without voltage transformer). ment) transmitted to the energy storage or transmitted via an inverter and an attached (ie downstream) electric machine to the energy storage. In direct transmission, power dissipation is generated only in the rectifier (and not in the inverter), while in a transmission via the inverter and the electric machine (as well as via the upstream rectifier) these two components can be operated as a DC voltage converter to different voltage levels between To be able to compensate rectifier and energy storage. In an AC direct charging mode is thus transmitted directly and in one change

Current adjustment charging mode, the power is passed through the inverter and the electric machine between the rectifier and the energy storage. In particular, power factor correction filtering (PFC filtering) is performed in both modes in the rectifier. Furthermore, rectification is performed in both modes in the rectifier. In the alternate current-mode charging mode, no up-conversion is preferably performed in the rectifier. In change

current direct charge mode, an up-conversion is preferably performed, in particular an up-conversion, which goes beyond a voltage increase for performing the Leistungsfaktororkorrek turfilterung. With power factor correction filtering, the voltage can be increased slightly, in particular by no more than 5%, 7%, 10%, 15%) in order to perform the filtering. This is understood to be the voltage boost required to perform power factor correction filtering. The up-conversion goes beyond this voltage increase and is associated with an increase in voltage by more than the voltage increase in the PFC filtering, such as an increase of more than 5%, 7%, 10%, 15% and preferably at least 50%. , 100%, 150% or 200%. The increase or

Voltage boost refers to the output voltage of the rectifier relative to the peak-to-peak value of the (possibly chained) voltage at the AC power port.

It is dependent on the ratio of the voltage levels between the rectifier and the energy storage of the alternating Direct current charging mode or the AC adapter charging mode. This makes it possible to take into account the voltage level of the energy storage, which changes during charging, and under different voltages or connection constellations on the AC power, especially since the AC power connection (depending on the charging station) may be one or more phases occupied.

A method for transmitting electrical power to an electrical energy store of a vehicle electrical system is described. The electrical energy store is preferably an accumulator, for example a traction accumulator, which may be in particular a lithium accumulator. The electrical energy store is in particular a high-voltage battery. The electrical power is transmitted from a charging station or another source of electrical energy outside the vehicle supply network. However, it is also possible to transfer power in the reverse direction. The vehicle electrical system is in particular a high-voltage vehicle electrical system. The prefix "high-voltage" designates a rated voltage that is above 60 V, in particular a nominal voltage of at least 120 V, 300 V, 350 V, 380 V or at least 450 V or 600 V, for example 380 V, 400 V or 800 V.

In an AC direct charging mode, the power from a rectifier (especially from its DC side) is transmitted directly to the energy storage. In this context, "directly" means that no voltage conversion is performed between the energy storage and the rectifier The rectifier may be an uncontrolled rectifier, but is preferably a controlled rectifier, preferably with the function of power factor correction filtering (on the AC side of the rectifier) In this case, the power factor in particular is increased and / or overshoot shares are reduced The rectifier is fed by an AC charging connection of the vehicle electrical system The AC charging connection is connected to the rectifier, in particular with an AC side of the rectifier. It can be seen that the rectifier can perform a (DC) up-conversion in addition to the DC direction, in particular an up-conversion that goes beyond a voltage increase caused by PFC filtering. The rectifier may thus be configured to perform an up-conversion that results in a voltage whose level is substantially higher than the peak-to-peak voltage of the (possibly chained) AC voltage at the AC charging port. An increase of no more than approximately 5%, 7%, 10% or 15% is not considered a substantial increase. A non-substantial increase is attributed to PFC filtering and not up-conversion (in the AC direct-charge mode).

As an up-conversion, an increase in the rectified voltage over the peak-to-peak voltage of the (possibly interlinked) AC voltage at the AC charging port will exceed, in particular, more than one voltage boost associated with PFC filtering. The up-conversion is preferably carried out by controlling the switches of the PFC-capable rectifier, in particular without a voltage conversion by a dedicated, a rectifier circuit downstream voltage converter (DC / DC converter). In particular, the up-conversion is performed in the AC direct-charge mode and is not performed in the AC-adaptive charge mode (in which only a voltage increase associated with the PFC function is performed).

The rectifier is thus in particular equipped with a voltage boost function (corresponding to the up-conversion). This function can be performed in AC Direct Charge mode and will not change

Power adjustment mode operated. In change

Current adjustment mode, the inverter and the electric machine are operated as a buck converter (buck converter).

In an AC adapter charging mode, the power is supplied from the rectifier via an inverter and via an electrical Transfer machine to the energy storage. The inverter (in particular its DC side) is connected to the DC side of the rectifier. The AC side of the inverter is connected to the electric machine, in particular to phase or winding terminals of the electric machine. The power is thus transmitted from the inverter via the electric machine to the energy storage. In this case, the power is transmitted via at least one winding or along at least one winding section of the electrical machine. In particular, the power can be transmitted via the electric machine by the power is fed to at least one phase connection of the electric machine and output from the (opposite) star point. This phase connection is also referred to as external phase connection. The power is transmitted through the inductance of the at least one winding (or Windlungsab section) of the electric machine.

When transmitting the power via the inverter and the electrical machine connected thereto, the inverter is operated together with the electric machine as a buck converter (buck converter) or as a synchronous converter in the buck converter mode. In this case, at least one circuit breaker of the inverter forms at least one switch of the buck converter while the at least one winding of the electrical machine is operated as an inductance of the step-down converter. The inverter and the electric machine can form a single or cascaded down converter.

The inverter or at least one circuit breaker thereof is driven in order to form a down-converting DC voltage converter together with the at least one winding of the electric machine. The down-converting DC-DC converter is also referred to as a down-converting DC / DC converter. A setpoint voltage for the voltage level delivered to the electric machine (ie the voltage at at least one inner phase connection or at the neutral point) can be predetermined, for example by a charge control, which is the Control of the circuit breaker of the inverter can be upstream. When operating the electric machine together with the inverter as a DC-DC converter, the neutral point can be resolved to, ie the internal phase terminals are separated from each other (all or a subset thereof).

A switching device can be used to select a mode from the at least two possible modes (change

Direct Current Charge Mode or Alternating Current Charge Mode). In the AC direct charging mode, a switching device connects the rectifier to the energy storage, in particular, directly (i.e., without voltage conversion). A switch of the switching device transmits the power. In the AC matching charging mode, the switching device connects the rectifier to the inverter, and produces a power path that leads through the inverter and the electric machine. For this purpose, a further switch of the switching device can be provided, which in this case transmits the power. The further switch and the former switch preferably together form the switching device. The two switches are alternately closed, i. when one switch is closed, the other switch is open. In an inactive mode both switches can be open.

The rectifier directs the power in at least one of the alternating current charging modes, preferably in the alternating current direct charging mode and in the alternating current adapter charging mode. The rectifier is in particular a controlled rectifier. Furthermore, the rectifier performs a power factor correction (PFC) function, in particular on the AC side of the rectifier. This increases the power factor, reduces harmonic components, or both. The rectifier can be designed as a Vienna rectifier. In order to perform the power factor correction filtering, the rectifier comprises (for each phase) at least one energy-storing component, for example a coil or a capacitor. The energy storage device can be connected in series the phase terminals of the rectifier (on the alternating current side) may be provided, for example in the form of a series inductance (for each phase). Alternatively or additionally, an energy-storing component can be connected in parallel to different phase connections, for example in triangular configuration or in a star configuration. The energy-storing component may be designed in the form of parallel capacitors, by means of which the phase connections are connected to one another. The rectifier can thus be designed for power correction filtering or perform power correction correction (PFC). A power correction filter can be equated with the change in power factor mentioned here or with the increase of the power factor and a reduction of harmonic components.

The inverter can be a controlled full-wave bridge, in particular with several phases, for example a more-phase BnC bridge, where n is twice the number of phases. The inverter can be designed as a B6C bridge. The inverter may be further configured as one or a plurality of H-bridges.

The inverter and / or the rectifier may comprise semiconductor switches, such as MOSFETs or IGBTs or diodes. The semiconductor switches are power switches.

In the AC adjustment charging mode, the power from the electric machine via a filter to the energy storage can be transmitted, in particular via a filter that the electric machine (seen from the inverter) nachge is switched or which is located between the electric machine and energy storage ,

In the AC adaptation charging mode, the inverter can be operated as a down-converting DC-DC converter (in short: down-converter). In particular, in the alternating current charging mode, the inverter, together with at least one winding of the electric machine, can be used as an alternator. be operated converter. Further, in the AC power-on charge mode, the inverter may be operated as a buck converter switch resulting from the combination of the inverter with the electric machine (and the appropriate drive). In particular, only a portion of all the power switches of the inverter are used to implement the switches of a buck converter. In this case, the down converter formed in this way can convert a DC voltage delivered by the rectifier into another, lower DC voltage. In AC direct charging mode, the inverter may be disabled. In particular, they are changing

direct current charging mode all switches of the inverter open. In the AC adapter charging mode, the DC voltage produced by rectification (and PFC filtering) is adjusted to a (lower) voltage level on the battery to avoid excessive currents due to a large voltage differential between rectified AC voltage and energy storage voltage.

The voltage delivered by the inverter or the electric machine can be filtered by means of a filter. This filter is connected downstream of the electric machine and is in particular connected to the star point or the inner Phasenan connections of the electric machine (switchless).

Furthermore, a DC charging mode can be provided. In this mode, the power (which is available as DC / DC voltage) is transferred directly from a DC charging port (ie without voltage conversion) to the energy storage. Alternatively or in combination with this, a DC voltage charge charging mode can be provided, in which the power is transferred from the DC charging port to the energy storage via a DC-DC converter. Here, the DC-DC converter may be a dedicated DC-DC converter for DC charging, or may be constituted by switches of the inverter and the electric machine. In the latter case, the power is transmitted from the DC charging port via the electric machine the inverter and from this to the energy storage. A switch that connects the energy storage directly to the DC power charging port is open in the DC voltage charging mode and closed in the DC charging mode (which may also be referred to as a direct DC charging mode).

Finally, a driving mode or a recuperation mode can be provided, in which the energy store is connected to the electric machine via the inverter. In this case, power is transferred from the energy store via the inverter to the electric machine where it is converted by the electric machine into mechanical power (traction mode), or the power is generated based on mechanical power in the electric machine and transmitted via the inverter to the energy store. In the drive mode and in the recuperation mode, the rectifier is deactivated and in particular has open circuit breakers.

There may be regenerative modes in which power from the electrical energy storage can be transferred to at least one of the charging ports, such as a first regenerative mode in which power from the energy storage is transferred directly through the (controllable) rectifier to the AC charging port (the rectifier then inverting ), a second regenerative mode in which power is transferred from the energy storage device via the electric machine and the connected thereto inverter and the (controllable) rectifier to the AC charging port (the rectifier then inverts and the inverter DC voltage converts), or a third regenerative mode, in which power from the energy storage is delivered to the Gleichspannungsladean circuit.

The rectifier can be operated in a rectifier mode in which the voltage applied to the AC charging terminal is only rectified and subjected to PFC filtering, whereby the rectifier does not undergo voltage conversion (which occurs with the PFC filtering). In other words, then the rectifier does not up-convert, but only possibly an increase in the voltage associated with the PFC filtering, such as an increase of not more than 5%, 7%, 10% or 15%. The rectified voltage results in this mode by the effective and possibly chain AC voltage at the AC charging port and possibly. by a non-significant voltage increase associated with PFC filtering. The rectifier may be configured to also operate in a rectifying voltage conversion mode in which it rectifies the voltage applied to the AC charging terminal and also performs an up-conversion that goes beyond a (non-substantial) voltage increase by PFC filtering. In order to be able to carry out an upshift (substantial, ie exceeding 5%, 7%, 10% or 15%), the rectifier has at least one energy-storing component, such as at least one capacitor or at least one inductor, as described above. The rectifier in particular has a power factor correction function (Power Factor Correction, PFC). This is realized by means of at least one energy-storing construction elements. The up-conversion is thus realized with components of the rectifier which also serve to realize the power factor correction function. By switching semiconductor switches of the rectifier according to parameters such as duty cycle, switching phase, phase offset and frequency, the up-conversion and / or the power factor correction function is realized and controlled.

In one embodiment, in the AC direct charging mode, the rectifier performs up-conversion (as well as rectification and PFC filtering). The inverter is deactivated here, in particular since the power is fed directly from the rectifier to the energy store. For example, the AC direct charging mode is set when the peak-to-peak voltage at the AC charging terminal (corresponding to the square root of two times the rms value of the voltage) is not more than a predetermined margin is below the voltage of the energy store. This is especially true for a single-phase occupancy of the AC charging port. Further, the AC direct charging mode can be set when the peak-to-peak value of the chained voltage at the AC charging terminal (corresponding to the square root of two multiplied by the chained voltage at the AC charging terminal) is not more than a predetermined margin below the voltage of the energy storage.

Thus, for example, with a voltage of the energy storage of more than 325 V or 350 V and single-phase occupancy of the AC charging connection at a mains voltage of 230 V effective AC voltage of the AC direct charging mode can be set. Here, the rectifier also works as a boost converter (boost converter), i. Performs a voltage boost so that the voltage delivered by the rectifier is higher than the voltage that would result from pure rectification and pure PFC filtering without (substantial) step-up.

For example, when three-phase AC (with a star fit of 230 V effective AC or a chained AC effective voltage of about 400 V) is charged, corresponding to a three-phase occupancy of the AC charging connection, and the voltage of the energy storage is above 600 V, 620 V. or 650 V or even 670 V, then the AC direct charge mode is also performed, in which the rectifier performs the function of Aufwärtswandeins in addition to the function of rectification and power factor correction and the power directly to the energy storage (and not via the inverter / electrical machine).

Furthermore, it can be provided that in the change

current adjustment charge mode, the rectifier does not upconvert and only rectifies and performs a PFC function. In this case, the inverter is activated and, together with at least one winding inductance of the electrical machine, performs a downward conversion. The performance is of the Rectifier via the inverter and the electric machine (in this order) led to the energy storage. The AC adapter charging mode is set, for example, when the peak-to-peak voltage at the AC charging terminal (corresponding to the square root of two multiplied by the rms value of the voltage) is not more than a predetermined margin over the voltage of the energy storage. This applies in particular to a single-phase occupancy of the AC charging connection. Furthermore, the change

direct current charging mode, when the peak-to-peak value of the chained voltage at the AC charging port (corresponding to the square root of two multiplied by the chained voltage at the AC charging port) is not more than a predetermined margin above the energy storage voltage , Thus, for example, with an effective AC voltage of the energy storage of not more than 325 V or 350 V and single-phase occupancy of the Wech selstromladeanschlusses at an effective mains voltage of 230 V AC voltage of the AC adjustment charging mode can be set. Here, the rectifier operates only as a rectifier (and PFC filter) and not as a boost converter (boost converter), ie performs no voltage boost (which would go beyond a voltage increase by PFC filtering) by. As a result, the voltage delivered by the rectifier corresponds to the voltage which results in pure DC direction (incl. PFC filtering) without upward conversion. For example, when charging with three-phase AC power (with a 230 V star or a chained voltage of approximately 400 V AC), corresponding to a three-phase occupancy of the AC charging port, the energy storage voltage is not above 600 V, 620 V, 650 V or also 670 V, then the AC adjustment charge mode is also performed, in which the rectifier performs only the functions of rectification and PFC filtering and not the function of Aufwärtswandeins. The rectifier does not output the power directly to the energy store but via the inverter / electric machine, which reduce the voltage level. The inverter and the electrical Here, the rectified voltage is adjusted by down-converting.

Furthermore, a vehicle electrical system with an AC charging connection and a rectifier will be described. This on-board vehicle network and its components correspond in particular to the on-board network and the components which have been described by means of which the method and embodiments thereof. The rectifier is selectable via a switching device either directly connected to an electrical energy storage, which corresponds to the AC direct charging mode, or is connected via an inverter and an electric machine to the electrical energy storage, this being the change

current adjustment charging mode corresponds. The switching device is thus set up to select two power paths (starting from the rectifier), both of which lead to the energy store. The one power path is direct and the other power path leads through the inverter and the connected electrical machine. The inverter is connected via the electrical machine with the electrical energy storage. The inverter is connected between the rectifier and the electric machine. Starting from the rectifier, the electric machine is switched nachge the inverter. Between the energy storage and the inverter, the electric machine is switched. The inner phase terminals of the electric machine (or at least one of them) is connected to the energy storage. The outer phase terminals of the electric machine are connected to the energy storage. The star point, at least one inner phase connection or a star point-side end of at least one winding or all windings of the electrical machine is connected to the energy store.

This optionally allows direct charging or charging via the inverter and the inverter downstream electric machine, which together can represent a down-converting DC voltage converter (down converter). In this case, at least one power switch of the inverter forms at least one A buck converter switch while at least one winding or portion thereof forms an inductor of the buck converter. The inverter or at least a subset of the power switches of the inverter is designed to also be operated as a switch of a buck converter.

The rectifier is arranged to rectify the AC current transmitted via the AC power charging terminal. Furthermore, it is set up for PFC filtering, in which, in particular, the power factor of the connection transferred via the AC charging terminal is increased and harmonics are reduced. Further, the rectifier is arranged to adjustably step up the voltage. Here, the rectifier can be designed as Vienna rectifier as mentioned above. In particular, the rectifier is also designed to realize a power correction filter. For this purpose, the rectifier has at least one energy storage component such as a coil or a capacitor. In other words, the rectifier is with a

Power correction filter equipped or is at least equipped with the function of the power correction filters or changing the power factor. Elements of the power correction filter are also used to perform an up-converting function of the rectifier. For this purpose, the rectifier in particular has at least one energy-storing element such as an inductor or a capacitor, as already mentioned. As at least one energy-storing element for forming the up-conversion function, preferably the same at least one energy-storing element is used with which the PFC filter function of the

Rectifier is realized. The rectifier is configured to carry out the AC adaptation charging mode and the AC direct charging mode. In particular, the control unit is arranged together with the rectifier, the AC adjustment charging mode and the change

current direct charging mode. The control unit is set up either the AC adaptation charging mode or Set the AC direct charge mode (or another mode).

As mentioned, the rectifier can be set up in at least one operating mode (in particular alternately

current direct charging mode) to work as a boost converter. It may further be provided that the rectifier does not work as an up-converter in the alternating current charge mode (apart from a non-essential voltage increase by the PFC function of, for example, not more than 5%, 7%, 10% or 15%). In particular, the rectifier may have components which are suitable for rectifying a voltage of at least 50%, 100%, 150% or 200% over the

Nominal peak-to-peak voltage at the AC connection (if necessary, taking into account the respective linkage factor) are designed.

The electric machine can be connected via a filter with the electrical energy storage. The filter may be connected downstream of a switch of the switching device (seen from the electrical machine). The filter is particularly direct, i. switchless, connected to the electrical Ma machine, in particular with at least one inner phase connection.

The vehicle electrical system may also have a DC charging connection. This is preferably connected via at least one switch to the energy storage. The

DC charging connection is not via the filter with the energy storage, which is optionally connected to the electrical machine (or this downstream).

The vehicle electrical system may further comprise a control device, which is also abbreviated be referred to as control be previously. The controller is drivingly connected to the switching device and the inverter. The control device can be divided into several parts and / or hierarchically and comprise a part which controls the switching over. direction, comprise a further part which controls the inverter or its power switch, and may also have a higher-level control unit. However, the hierarchy or structure of the control device can be multifarious and will not be discussed further below. The control device is set up in the change

direct current charging mode to control the switching device to connect the AC charging port directly to the energy storage. The controller is further configured to drive the switching device to connect the AC charging port to the inverter in an AC matching charging mode. The control device is set up in this mode to control the inverter to work together with at least one winding of the electric machine as DC voltage converter. The switching device is in particular arranged to switch the inverter inactive in the AC direct charging mode, i. to provide all switches of the inverter in open condition.

The controller may further be configured to openly provide both switches of the switching device in a DC charging state while a switch is provided closed connecting the DC charging port to the energy storage.

The switching device may have a first switch which connects the rectifier to the energy store. The switching device may include a second switch provided between the energy storage and a connection connecting the rectifier to the inverter. In particular, the second switch is provided between the electric machine and the energy storage or connects these two components. The second switch can be provided in particular at the star point of the electric machine (or at its inner phase connections) and can supply this or such. connect them to the energy storage. In the AC charging modes, the first and second switches are alternately open or closed. In an alternative embodiment, the switching device comprises only the first switch, while the second switch is realized by the switches of the inverter. In this case, the power path that leads through the inverter or via the electric machine (and when changing

current adjustment charge mode is used for transmission) is opened or closed by the switches of the inverter itself, while the path leading directly from the rectifier to the energy storage path is opened or closed by the first switch. The control device is designed to alternately open or close the first switch on the one hand and the switches of the inverter on the other hand in the alternating-current charging modes. Herein, the controller may be configured to close the first switch and openly drive the switches of the inverter in the AC direct-charge mode, and open the first switch open and the switches of the inverter closed in the AC adaptive charge mode. Instead of controlling all switches of the inverter closed, a subgroup of the full bridges or even a full bridge of the inverter can be controlled closed.

The vehicle electrical system described here is designed to carry out the method. The method uses the be described components of the vehicle electrical system.

FIG. 1 shows an overview for a more detailed explanation of the vehicle electrical system or the method.

A symbolically represented on-board vehicle network BN comprises an energy store ES in the form of a traction battery and an inverter I which is connected via a first switch Bl to the energy storage unit ES. On the opposite side, an electric machine M is connected to the inverter. The electric machine M has in particular a plurality of phases and may be designed as a permanently excited, self-excited or externally excited electrical machine, for example as a synchronous machine, or may be an asynchronous machine. The electric machine M has a neutral point SP. This is located at the inner phase terminals of the electric machine. The star point SP can be designed separable.

Seen from the inverter I, the electric machine is followed by a second switch S1. The second switch S1 connects the electric machine M (in particular its neutral point SP or at least one inner phase connection of the electric machine EM) to the energy store, in particular directly, ie. without changing the voltage. An optional filter F can be provided, which is located between the electric machine M and the energy store ES, in particular between the second switch S1 and the energy store.

An AC charging terminal ACLB (designed approximately as a charging socket) is connected via a rectifier GR to the first switch Bl and to the inverter I. The first switch Bl and the inverter I (in particular its DC side) are connected to the DC side of the rectifier GR ver. The AC charging terminal ACLB is connected to an AC mains ACN which is located outside the vehicle electrical system and can be seen in a charging station LS. AC mains ACN includes an AC source. The rectifier GR has the function of a power factor correction filter (in addition to the function of rectification), so that the power factor prevailing at the AC charging terminal ACLB can be adjusted and in particular (compared to the use of a rectifier without PFC function) can be increased.

If the first switch Bl closed and the second switch S2 open, then the rectifier GR is directly connected to the energy storage ES. This corresponds to the change

current direct charging mode. If the first switch Bl is open and the second switch S2 is closed, then the rectifier GR is connected to the energy store ES via the inverter I and the electric machine M (in this order). This is the inverter together with the electric machine as mentioned above as (in particular down-converting) DC voltage converter operated. The optional filter F enables the suppression of switching pulses in the electrical system BN, which are generated by switching processes in the inverter I when operating as a (switch unit of) a DC-DC converter.

A ground switch B2 connects the energy storage switchable with a negative supply potential of the vehicle electrical system. The aforementioned switches Bl and S2 and a switch B3 are seen in a positive supply potential rail before. A battery disconnect switch B3 is provided between the filter and the energy storage ES. The switches B2 and B3 are closed in the AC charging modes and can be provided open in case of failure or inactive electrical system.

An optional DC charging connection DCLB allows the connection of the vehicle electrical system BN to a DC network DCN, which lies outside the vehicle electrical system BN. The DC network DCN may be part of the charging station LS. The DC charging terminal DCLB is connected to the power storage via a DC voltage switch S2 (and via the switch B3). The connection between the switch S2 and the energy store ES is direct, i. without voltage transformer. However, it may be nachge switches for voltage level adjustment the DC voltage charging connection DCLB a DC-DC converter. An alternative (or additional) connection between the DC charging terminal DCLB and the energy storage ES is via a switch CI. The switch switch CI connects the DC charging terminal DCLB with the energy storage ES. If this is closed, power can be transferred directly from the DC charging connection DCLB to the energy storage ES.

A control device CT shown in abstract is connected to the switches Bl and S1 at control. The Steue tion device CT controls as mentioned in the AC lademodes the switches Bl and S1 alternately. For this reason form the switches Bl and S1 (by the alternate to control) a switching device. The controller CT is also drivingly connected to the switches S2, B3 and CI (if present) closed during DC charging while the switches S1, B1 are open. The control device CT is also drivingly connected to the switches S2 and B3 and CI, respectively, in order to control them closed, in contrast to the switches Bl and Sl, when a DC charging mode is present. The control device can furthermore be connected to the rectifier GR and to the inverter I in a triggering manner. If no switch Sl is provided, instead of this switch, the switches of the inverter I may be opened or closed by the controller, such as when switching between the AC charging modes. The control device CT is set up by the driving connection with the rectifier GR to set a power factor that prevails from the rectifier at the AC charging terminal ACLB, and to filter harmonics or to mitigate. As mentioned, the controller CT may be multi-part or hierarchical forms. The controller CT may further comprise an input for inputting a desired operating mode. The controller may be further configured to execute the traction mode or recuperation mode, as described above.

Optional or alternative components and connections are shown dashed, dotted or dash-dotted.

Claims

claims

1. A method for transmitting electrical power to an electrical energy storage (ES) of a vehicle electrical system (BN), wherein in an AC direct charging mode, the power from a rectifier (GR) of the vehicle electrical system (BN) powered by an AC charging port (ACLB) is transmitted directly to the energy storage (ES) of the vehicle electrical system (ES) and in an AC adapter charging mode, the power from the rectifier (GR) via an inverter (I) and from the inverter (I) via an electric machine (EM) is transferred to the energy storage (ES).

2. The method of claim 1, wherein in the change

Direct current charging mode, a switching device (Bl, Sl) connects the rectifier (GR) to the energy store (ES) and in the AC adapter charging mode, the switching device (Bl, Sl) connects the rectifier (GR) to the inverter (I).

The method of claim 1 or 2, wherein the rectifier (GR) rectifies the power in at least one of the AC charging modes and performs a power factor correction filter function and / or alternately

Direct current charging mode performs an up-conversion.

4. The method according to any one of the preceding claims, wherein in the AC adjustment charging mode, the power from the electric machine (EM) via a filter (F) to the energy storage (ES) is transmitted.

5. The method according to any one of the preceding claims, wherein in the AC adapter charging mode, the inverter (I) is operated as a DC-DC converter and converts a DC voltage output from the rectifier (GR) in a lower DC voltage.

6. The method according to any one of the preceding claims, wherein in a DC charging mode, the power from a DC charging port (DCLB) directly to the energy storage (ES) is transmitted.

7. Vehicle electrical system with an AC charging port

(ACLB) and a rectifier (GR), wherein the rectified rectifier (RG) via a switching device (Bl, Sl) selectable either directly with an electric energy giespeicher (ES) is connected or via an inverter (I) and an electric machine ( EM) is connected to the electrical energy store (ES), the inverter (I) being connected to the electrical energy store (ES) via the electrical machine (EM).

An on-board vehicle electrical system according to claim 7, wherein the rectifier (GR) is arranged to rectify the AC power transferred via the AC charging port (ACLB) and as a power factor correction filter for the power transmitted via the AC charging port (ACLB).

9. vehicle electrical system according to claim 7 or 8, wherein the

electrical machine is connected via a filter with the electrical energy storage (ES).

10. Vehicle electrical system according to one of claims 7 - 9, which further comprises a DC charging connection (DCLB), which is connected via a switch (S2; B3; CI) to the energy store (ES).

11. Vehicle electrical system according to one of claims 7 - 10, further comprising a control device (CT), which is drivingly connected to the switching device (Bl, Sl) and the inverter (I), wherein the control device (CT) is arranged in one AC direct charging mode, the switching device (Bl, S2) to control the change AC power supply (ACLB) directly to the energy storage (ES) to connect, and the control device (CT) is also set up, in a change

current adjustment charging mode to drive the switching device (Bl, S2), the AC charging port (ACLB) with the

Inverter (I) to connect and the inverter (I) to control, together with at least one winding of the electric machine (M) to work as a DC-DC converter and in particular as a downward swandler.

12. Vehicle electrical system according to one of claims 7 - 11, wherein the rectifier (GR) is arranged to operate in at least one operating mode as a boost converter.