Charging device and method for operating the charging device

Abstract

A charging device for a vehicle, wherein the charging device (500) has an input-side input terminal unit (100) for connecting a single-phase or three-phase alternating voltage, a PFC stage (200) for providing a direct voltage at an intermediate terminal (300) and a bipolar alternating voltage terminal (400) for providing an alternating voltage.

Description

[0001] Description

[0002] title

[0003] Charger and method for operating the charger

[0004] The invention relates to a charger and a method for operating the charger. Furthermore, the invention relates to a powertrain with a charger, a vehicle with a powertrain, a computer program, and a machine-readable storage medium.

[0005] State of the art

[0006] Chargers, for example in electric vehicles or hybrid vehicles, are used to recharge batteries, preferably accumulators or traction batteries, from an electrical energy source, preferably an external AC source or the public AC grid. To do this, the charger converts a sinusoidal alternating current from the external energy source into a direct current. With single-phase alternating current, the power pulses at twice the frequency of the alternating current.

[0007] Chargers preferably have two-stage power electronics. A first stage, the so-called power factor correction stage, or PFC stage, converts the sinusoidal input voltage from the AC mains into a DC voltage. A second stage consists of a DC-DC converter or DC / DC converter, which ensures galvanic isolation via a transformer and adjusts the voltage levels. The output voltage and / or output current for charging the battery is preferably adjusted using an electrical circuit and a control system. An intermediate circuit capacitor is arranged between the two stages, which buffers the power pulsation at twice the frequency of the AC current of the energy source. This intermediate circuit is typically implemented using at least one electrolytic capacitor.These topologies enable the maintenance of a nearly sinusoidal input current on the grid side to meet grid-side standards, galvanic isolation between the grid and the vehicle to meet safety requirements, and the provision of a constant DC output current on the battery side to minimize the load on the battery during charging.

[0008] In an electric vehicle, the battery is also connected to an inverter to supply the electric drive motor with power. A DC-DC converter is connected in parallel to the inverter to supply a low-voltage network, or the vehicle's on-board electrical system, with power for the control units. It is known to generate an alternating voltage using an inverter connected to the on-board electrical system to supply power to an on-board AC socket. The AC socket is intended to power common household appliances within the vehicle. Common household appliances include media players, computers, chargers for mobile devices, coolers, and coffee machines.

[0009] The resulting multitude of voltage converters within a vehicle is complex and requires a lot of space. Therefore, there is a need for simple, compact, and efficient solutions to provide the multitude of required voltages.

[0010] Disclosure of the invention

[0011] A charger for a vehicle is provided, the charger comprising on the input side a preferably three-phase input connection unit for connecting a single- to three-phase alternating voltage, a PFC stage for providing a direct voltage at an intermediate connection, and a two-pole alternating voltage connection for providing an alternating voltage. The PFC stage comprises a first, a second, and a third half-bridge. The first, second, and third half-bridges each comprise a series circuit with a high-side switch and a low-side switch. A center tap between the high-side switch and the low-side switch of a half-bridge can be connected via a first, second, and third choke to a first, second, and third input connection of the preferably three-phase input connection unit via a first, second, and third connection line.The center tap of the first half-bridge can thus be connected to the first input terminal via the first choke and the first connection line. The center tap of the second half-bridge can thus be connected to the second input terminal via the second choke and the second connection line. The center tap of the third half-bridge can thus be connected to the third input terminal via the third choke and the third connection line. The half-bridges are connected in parallel and their ends are connected to the two-pole intermediate terminal. The high-side switches are connected to a positive intermediate terminal and the low-side switches are connected to a negative intermediate terminal of the two-pole intermediate terminal. The charger comprises a fourth half-bridge which is connected in parallel to the first, second and third half-bridges.The fourth half-bridge comprises a high-side switch and a low-side switch, wherein a center tap between the high-side switch and the low-side switch of the fourth half-bridge is switchably connected to a second AC voltage terminal of the two-pole AC voltage terminal via a sixth switching element. A fourth switching element, preferably a fourth changeover contact, is provided and configured to establish a connection via the third choke between the third half-bridge and a first AC voltage terminal of the two-pole AC voltage terminal or a connection via the third choke between the third half-bridge and the third connecting line to the third input terminal. Further advantageously, the third connecting line can be decoupled from the P FC stage and thus from the first and second capacitors by means of the fourth switching element.Preferably, the third connection line is therefore only connected to the PFC stage after the first and second capacitors have been charged. This preferably prevents an inrush current when the third connection line is switched on. Preferably, a pre-charging resistor between the third input connection and the third connection line can be omitted. Preferably, during operation of the two-pole AC voltage connection, electrical energy present at the intermediate connection is provided at the two-pole AC voltage connection. The electrical energy at the intermediate connection is preferably provided by an external energy source, or the infrastructure or EVSE (Electric Vehicle Supply Equipment), via the input connection unit and the P FC stage, or by a battery connected to the charger, preferably a traction battery of the vehicle, via a bidirectional DC / DC converter connected to the intermediate connection.

[0012] To provide a two-pole AC voltage connection at which a controllable AC voltage can be provided, a fourth half-bridge is added to a P FC stage of a charger, with its center tap being fed to a second AC voltage connection. The first AC voltage connection is connected via a third choke of the P FC stage to the center tap of a third half-bridge of the P FC stage. Advantageously, a circuit for a charger is provided that enables a controllable AC voltage to be provided at the two-pole AC voltage connection. The AC voltage can be provided during a charging process for charging the battery by means of the charger. Preferably, the DC voltage at the intermediate connection is converted into a desired AC voltage by means of the third and fourth half-bridge.Preferably, the charger can influence the voltage and current at the load connected to the two-pole AC voltage connection, even during the battery charging process. Overloading of the external energy source can preferably be prevented by deliberately opening the high-side and low-side switches of the third and fourth half-bridge, thereby disconnecting a connected load. Preferably, the charger and / or the connected load can be protected in the event of a short circuit by an overcurrent shutdown.

[0013] An external energy source is preferably a single-phase, two-phase, or three-phase AC voltage network, preferably the public low-voltage grid. In a North American or Japanese region, this is preferably a single-phase AC voltage network with 120 or 240 volts. In a Chinese or European region, this is preferably a three-phase AC voltage network with approximately 230 volts. For charging the charger, the charger is connected to a corresponding AC voltage network or to the corresponding AC voltage. A battery to be charged is preferably an accumulator or a traction battery, which uses energy to operate an electric drive train of a vehicle. A rectification circuit is preferably a rectifier for converting the alternating current into direct current.A high-side switch or a low-side switch of a semiconductor bridge is preferably a power semiconductor switch comprising an intrinsic diode, preferably an IGBT or MOSFET, preferably based on Si, SiC, or GaN technology. The phrase "connecting, for example, a center tap to a connecting line" preferably means connecting, contacting, or connecting the components by means of an electrically conductive line or a galvanic connection. The phrase "blocking, preventing, decoupling, or preventing a current flow" means breaking an electrically conductive line or connection. The phrase "switched" is preferably used synonymously with "electrically connected," where "switchably connected" means that an electrical connection can be established or broken, preferably by means of a switch or switching element.Preferably, the wording arranged is used to define the position of an electrical component, preferably a switch or switching element, within the circuit topology, wherein this comprises an electrical connection with the electrical components arranged adjacent thereto.

[0014] In another embodiment, the input terminal unit comprises a neutral conductor terminal. A series circuit of a first and a second diode is connected in parallel to the first to fourth half-bridges. The first and the second diode are connected in reverse direction and prevent, block, or interrupt a current flow from the positive intermediate terminal to the negative intermediate terminal and allow a current flow from the negative intermediate terminal to the positive intermediate terminal. A center tap between the first and the second diode is connected to the neutral conductor terminal via a neutral conductor. A series circuit of a first and a second capacitor is connected in parallel to the half-bridges.Furthermore, a fifth switching element is provided which is designed to connect the second choke, which is connected on the one hand to the second half-bridge, either to the neutral conductor or to the second connecting line to the second input terminal.

[0015] A fifth switching element, preferably a fifth changeover contact, is arranged between the second choke and the second connecting line. Depending on the switching position, the second choke is thus connected to the neutral conductor or to the second connecting line to the second input connection. Advantageously, a possibility is created to provide an alternating voltage at the input connection unit at the first input connection and the neutral conductor connection. Preferably, a direct voltage at the intermediate connection is converted into a desired alternating voltage by means of the first and second half-bridges and provided as an alternating voltage at the first input connection and the neutral conductor connection. The electrical energy at the intermediate connection is preferably provided by a battery connected to the charger, preferably a traction battery of the vehicle, via a bidirectional DC / DC converter connected to the intermediate connection.

[0016] In another embodiment of the invention, the second connecting line is divided into a first part of the second connecting line and a second part of the second connecting line. A second switching element is provided, which is arranged between the first part of the second connecting line and the second part of the second connecting line and is configured to conduct a charging current from the second input terminal via the first part and the second part of the second connecting line to the second choke, or to conduct a charging current from the first connecting line via the second part of the second connecting line to the second choke.

[0017] A second switching element, preferably a second changeover contact, is arranged between a first part of the second connecting line and a second part of the second connecting line. Depending on the switching position of the second switching element, a charging current is thus conducted from the second input connection via the first part and the second part of the second connecting line to the second choke, or a charging current is conducted from the first connecting line via the second part of the second connecting line to the second choke. Advantageously, a possibility is created to partially branch off a single-phase charging current flowing via the first connecting line and to conduct it via the second part of the second connecting line to the second choke and second half-bridge. The load on the first choke and the first half-bridge can thus be reduced, preferably when a single-phase charging current is present.Preferably, a single-phase charging current results when a single-phase alternating voltage is connected to the input terminal. Further advantageously, the first part of the second connecting line can be decoupled from the PFC stage and thus from the first and second capacitors by means of the second switching element. Preferably, the first part of the second connecting line is therefore only connected to the PFC stage after the first and second capacitors have been charged. Preferably, an inrush current is thus prevented when the first part of the second connecting line is switched on. Preferably, a pre-charging resistor between the second input terminal and the first part of the second connecting line can be omitted. Preferably, due to the design of the second switching element as a second changeover contact, a short circuit between the first connecting line and the first part of the second connecting line is prevented.Preferably, a short circuit between the first input terminal and the second input terminal would be possible by means of an incorrectly controlled simple switching element; by means of a second changeover contact, this error case can be reliably excluded during control.

[0018] In another embodiment, a first switching element is provided and configured to enable or interrupt a current flow between the first input terminal and the first connecting line or the first choke of the P FC stage.

[0019] A first switching element is arranged between the first connecting line and the first input connection. Depending on the switching position, a current flow or a charging current from the first input connection towards the first choke of the P FC stage is thus enabled or prevented. Advantageously, a possibility is created to interrupt or switch on a charging current via the first connecting line. Preferably, a thermistor or NTC resistor is connected in parallel to the first switching element and is used to limit an inrush current. Preferably, the inrush current flows from the first input connection via the P FC stage into the first and / or the second capacitor. Preferably at low temperatures, the resistance of the thermistor is high and reduces the inrush current. After switching on, the thermistor heats up due to the current flow and loses its high initial resistance.Preferably, in order to reduce the losses of the thermistor, the latter is bridged by closing the first switching element when the first and / or second capacitor is substantially charged.

[0020] In another embodiment, a third switching element is provided and is configured to enable or interrupt a charging current between the third input terminal and the third connecting line or the third choke of the P FC stage.

[0021] A third switching element is arranged between the third connecting line and the third input connection. Depending on the switching position, a current flow or a charging current from the third input connection towards the third choke of the PFC stage is thus enabled or prevented. Advantageously, a possibility is created to interrupt or switch on a charging current via the third connecting line, preferably when a three-phase charging current is present. Preferably, a thermistor or NTC resistor is connected in parallel to the third switching element and is used to limit an inrush current. The inrush current preferably flows from the third input connection via the PFC stage into the first and / or second capacitor. Preferably at low temperatures, the resistance of the thermistor is high and reduces the inrush current. After switching on, the thermistor heats up due to the current flow and loses its high initial resistance.Preferably, in order to reduce the losses of the thermistor, the latter is bridged by closing the third switching element when the first and / or second capacitor is substantially charged.

[0022] In another embodiment, a seventh switching element is arranged between the center tap between the first and the second diode and a center tap between the first and the second capacitor.

[0023] A seventh switching element is connected between the center tap between the first and second diodes and the center tap between the first and second capacitors. Depending on the switching position, a current flow between the center taps of the diode series circuit and the capacitor series circuit is thus enabled or prevented. Advantageously, a possibility is created to interrupt or switch on a current flow, preferably when a two- or three-phase charging current is present, between the center tap between the first and second diodes and the center tap between the first and second capacitors. The seventh switching element is preferably closed for operation of the charger with an asymmetric load. An asymmetric load occurs when the charger is operated with a two-phase mains or with an asymmetric load when the charger is operated with a three-phase mains, i.e. two-phase or three-phase alternating voltage.In these cases, the resulting current on the neutral conductor flows via the closed seventh switching element. With a symmetrical load, the alternating voltages on the first, second and third connecting lines are the same and the phase shift of the alternating voltages between each other is 120 degrees. In this case, the sum of the phase currents and the resulting current on the neutral conductor is zero. With an asymmetrical load, the alternating voltages on the first, second and third connecting lines are not all the same and / or the phase shift of the alternating voltages between each other is not 120 degrees. In this case, the sum of the phase currents and the resulting current is not zero. When the switching element is closed, a current flow for this total current is preferably enabled via the neutral conductor to the neutral conductor connection.

[0024] In another embodiment, in order to provide electrical energy at the two-pole AC voltage connection, a DC voltage provided at the positive intermediate terminal and at the negative intermediate terminal is provided at least partially as AC voltage at the first AC voltage connection and at the second AC voltage connection, wherein the fourth switching element establishes a connection from the center tap of the third half-bridge via the third choke to the first AC voltage connection and the sixth switching element establishes a connection from the center tap of the fourth half-bridge to the second AC voltage connection.

[0025] Advantageously, the fourth and sixth switching elements are connected in such a way that a controllable alternating voltage can be provided at the two-pole AC voltage connection. The direct voltage at the intermediate connection is converted into a desired alternating voltage by means of the third and fourth half-bridges, preferably by filtering via the third choke and a fourth capacitor between the first and second AC voltage connections. Thus, the third and fourth half-bridges act like an inverter to generate a preferably single-phase alternating voltage from a direct voltage at the two-pole AC voltage connection.

[0026] In another embodiment, to provide electrical energy at the intermediate connection

[0027] - either an alternating voltage provided at the input connection unit is provided via the PFC stage at least partially as a direct voltage at the positive intermediate connection and at the negative intermediate connection, wherein a charging current is conducted via at least the first connection line and the second connection line, or at least the second part of the second connection line, via the PFC stage to the intermediate connection and preferably the entire charging current is returned via the neutral conductor,

[0028] - or a DC voltage provided by a bidirectional DC-DC converter connected to the intermediate terminal and a battery connected thereto, preferably a traction battery, is provided at the positive intermediate terminal and at the negative intermediate terminal, wherein for this purpose the bidirectional DC-DC converter converts the voltage of the battery to the DC voltage to be provided at the positive intermediate terminal and at the negative intermediate terminal.

[0029] Advantageously, a topology is provided which enables the provision of a direct voltage at the intermediate connection, wherein the energy for this can be provided by an external energy source or by a battery, preferably internal to the vehicle.In one embodiment, the charger is configured to provide an alternating voltage at the input terminal unit at the first input terminal and the neutral conductor terminal, wherein, in order to provide electrical energy at the first input terminal and at the neutral conductor terminal, a direct voltage provided at the positive intermediate terminal and at the negative intermediate terminal is provided at least partially as an alternating voltage at the first input terminal and at the neutral conductor terminal, wherein a current between the positive intermediate terminal and the first input terminal is conducted via the first choke and a current between the negative intermediate terminal and the neutral conductor terminal is conducted via the second choke.

[0030] Advantageously, a topology is provided which enables the provision of an alternating voltage at the first input terminal and the neutral conductor terminal, the energy for this being provided by a battery, preferably internal to the vehicle.

[0031] Furthermore, the invention relates to a drive train of a vehicle with a charger as described above, wherein the drive train comprises, in particular, a traction battery, an inverter, and / or an electric machine. Advantageously, a drive train of an electric vehicle with a charger with a simplified circuit topology is provided.

[0032] Furthermore, the invention relates to a vehicle with a drive train as described above.

[0033] Advantageously, a vehicle is provided with a charger having a simplified circuit topology.

[0034] Furthermore, the invention relates to a method for operating a charger as presented above, comprising the step of controlling the fourth and sixth switching elements and the high-side and low-side switches of the third and fourth half-bridge to provide electrical energy at the two-pole AC voltage connection. By controlling the switches of the third and fourth half-bridge and closing the fourth and sixth switching elements, a DC voltage applied to the intermediate connection is converted into an AC voltage, which is applied to the two-pole AC voltage connection. Advantageously, a method is provided which enables the provision of a controllable AC voltage at the two-pole AC voltage connection.

[0035] Furthermore, the invention relates to a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the described method.

[0036] Furthermore, the invention relates to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the described method.

[0037] It is understood that the features, characteristics and advantages of the charger apply accordingly to the method or the powertrain and the vehicle and vice versa.

[0038] Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings.

[0039] Short description of the drawing

[0040] In the following, the invention will be explained in more detail with reference to some figures, which show:

[0041] Figure 1 is a schematic representation of an embodiment of a circuit topology for a charger known from the prior art

[0042] Figure 2 shows a schematic representation of a first embodiment of a circuit topology for a charger, Figure 3 shows a schematic representation of an exemplary current or energy flow in a first operating mode of the circuit topology for a charger,

[0043] Figure 4 is a schematic representation of an exemplary current or energy flow in a second operating mode of the circuit topology for a charger

[0044] Figure 5 is a schematic representation of an exemplary current or energy flow in a third operating mode of the circuit topology for a charger

[0045] Figure 6 shows a schematic representation of a vehicle with a drive train with a charger,

[0046] Figure 7 is a schematic flow diagram for a method for operating a charger

[0047] Embodiments of the invention

[0048] Figure 1 shows a charger 500, preferably for a vehicle. The charger 500 includes an input connection unit 100 for connecting a single- to three-phase AC voltage, a PFC stage 200 for providing a DC voltage at an intermediate connection 300. The PFC stage 200 of the charger 500 includes a first 210, a second 220, and a third 230 half-bridge. The first, second and third half-bridges 210, 220, 230 each comprise a series circuit with a high-side switch 211, 213, 215 and a low-side switch 212, 214, 216. A center tap between the high-side switch and the low-side switch of a half-bridge can be connected via a first, second and third choke 202, 204, 206 to a first, second and third input terminal LI, L2, L3 of the input connection unit 100 via a first, second and third connection line 110, 120, 130.Thus, the center tap of the first half-bridge 210 is connectable to the first input terminal L1 via the first choke 202 and the first connecting line 110. Thus, the center tap of the second half-bridge 220 is connectable to the second input terminal L2 via the second choke 204 and the second connecting line 120. Thus, the center tap of the third half-bridge 230 is connectable to the third input terminal L3 via the third choke 206 and the third connecting line 130. The half-bridges 210, 220, 230 are connected in parallel. Their ends are connected to the two-pole intermediate terminal 300. The high-side switches are connected to a positive intermediate terminal 310 and the low-side switches to a negative intermediate terminal 320. A DC-DC converter 450 is preferably connected to the intermediate terminal 300.The DC voltage at the intermediate connection 300, which is present on the input side of the DC-DC converter 450, is preferably converted into a charging voltage for charging a battery 470, preferably a traction battery or high-voltage battery, that can be connected to the output side of the DC-DC converter 450. Preferably, a further DC-DC converter 460, preferably a step-down converter, is connected in parallel to the battery 470 to convert the charging voltage into a low-voltage voltage for charging a low-voltage battery 462 and for supplying a vehicle's electrical system to supply the vehicle's control units. The low-voltage battery 462, as well as preferably other low-voltage consumers (not shown), are connected to the vehicle's electrical system. The further DC-DC converter 460 is preferably a bidirectional DC-DC converter.Preferably, the additional DC-DC converter 460 can be used to precharge the high-voltage intermediate circuit before the battery 470 is connected to the charger 500. The high-voltage intermediate circuit is connected to the output side of the DC-DC converter 450. An inverter 480 is preferably connected to the vehicle electrical system, which converts the low-voltage voltage into an alternating voltage to supply standard household consumers. Standard household consumers are preferably supplied with an alternating voltage, which, depending on the region, is approximately 120 volts or 230-240 volts. For this purpose, AC consumers can be connected to the first connection terminal 482 and the second connection terminal 484.

[0049] Starting from the charger 500 according to Figure 1, the charger 500 according to the invention according to Figure 2 comprises a two-pole AC voltage connection 400.To provide an alternating voltage at the alternating voltage connection 400, the charger 500 comprises a fourth half-bridge 240, which is connected in parallel to the first, second and third half-bridges 210, 220, 230, with a high-side switch 217 and a low-side switch 218, wherein a center tap between the high-side switch and the low-side switch of the fourth half-bridge 240 is switchably connected to a second alternating voltage connection 420 of the two-pole alternating voltage connection 400 via a sixth switching element S6, and wherein a fourth switching element S4 is provided, which is configured to establish a connection via the third choke 206 between the third half-bridge 230 and a first alternating voltage connection 410 or a connection via the third choke 206 between the third half-bridge 230 and the third connection line 130 to the third input connection L3.The two-pole AC connection is preferably designed to supply standard household appliances during operation. Standard household appliances are preferably supplied with an AC voltage of approximately 120 volts or 230-240 volts, depending on the region.

[0050] The input connection unit 100 preferably further comprises a neutral conductor connection NI. A series circuit of a first D1 and a second D2 diode is connected in parallel to the half-bridges 210, 220, 230, 240. The first and second diodes D1, D2 are connected in the reverse direction and prevent a current flow from the positive intermediate terminal 310 to the negative intermediate terminal 320 and enable a current flow from the negative intermediate terminal 320 to the positive intermediate terminal 310. A center tap between the first and second diodes D1, D2 is connected to the neutral conductor connection NI via a neutral conductor 140. A series circuit of a first C1 and a second C2 capacitor is connected in parallel to the half-bridges 210, 220, 230, 240.A fifth switching element S5 is provided and configured to connect the second choke 204, which is connected on the one hand to the second half-bridge 220, either to the neutral conductor 140 or to the second connecting line 120 to the second input terminal L2.

[0051] Preferably, the second connecting line 120 is divided into a first part of the second connecting line 120_l and a second part of the second connecting line 120_2. For this purpose, a second switching element S2 is provided, which is arranged between the first part of the second connecting line 120_l and the second part of the second connecting line 120_2. The second switching element S2 is configured to conduct a charging current from the second input terminal L2 via the first part and the second part of the second connecting line 120_l, 120_2 to the second choke 204 or to conduct a charging current from the first connecting line 110 via the second part of the second connecting line 120_2 to the second choke 204.

[0052] Preferably, a first switching element S1 is provided and configured to enable or interrupt a current flow between the first input terminal LI and the first connecting line 110.

[0053] Preferably, a third switching element S3 is provided and configured to enable or interrupt a charging current between the third input terminal L3 and the third connecting line 130.

[0054] Precharging resistors, preferably switchable resistors, thermistors or NTC resistors, are preferably connected in parallel to the first S1 and the third S3 switching element so that a starting current decays and is limited when an alternating voltage is connected to the input connection unit 100 before the first and the third switching element S1, S3 are closed.

[0055] Preferably, a seventh switching element S7 is arranged between the center tap between the first and second diodes D1, D2 and a center tap between the first and second capacitors C1, C2.

[0056] Preferably, a current sensor (A) is arranged on each of the first, second, and third chokes 202, 204, 206 to determine the current through the respective choke 202, 204, 206. Depending on the determined currents, the high-side switches and the low-side switches as well as the switching elements are preferably controlled to implement the desired operating modes. Preferably, voltage sensors (V) are arranged between each of the first, second, and third connecting lines 110, 120, 130 and the neutral conductor 140 to determine the voltages. Preferably, a voltage sensor (V) is also arranged between each of the positive and negative intermediate terminals 310, 320 and between the center tap between the first and second capacitors C1, C2 and the negative intermediate terminal 320.Depending on the measured voltages, the high-side switches and the low-side switches, as well as the switching elements, are preferably controlled to implement the desired operating modes. The negative intermediate terminal 320 is preferably connected to ground (GND AC). GND AC is preferably an internal voltage potential.

[0057] The switching elements are preferably provided as semiconductor switch components (IGBT or MOSFETS, based on Si, SiC or GaN) or as contactors or relays.

[0058] Figure 3 shows a schematic representation of an exemplary current or energy flow in a first operating mode of the circuit topology for a charger 500. Preferably, to provide electrical energy at the two-pole AC voltage connection 400, a DC voltage provided at the positive intermediate terminal 310 and at the negative intermediate terminal 320 is provided at least partially as an AC voltage at the first AC voltage connection 410 and at the second AC voltage connection 420. For this purpose, the fourth switching element S4 preferably establishes a connection from the center tap of the third half-bridge 230 via the third choke 206 to the first AC voltage connection 410, and the sixth switching element S6 establishes a connection from the center tap of the fourth half-bridge 240 to the second AC voltage connection 420.Consequently, the current flow illustrated in Figure 3 results from the positive intermediate terminal 310 via the third half-bridge 230 and the third choke 206 via the fourth switching element S4, preferably via a filter 404, preferably an EMC filter, to the first AC voltage terminal 410 and from the second AC voltage terminal 420 via the closed switching element S6 back via the fourth half-bridge 240 to the negative intermediate terminal 320. Preferably, a fourth capacitor C4 between the first AC voltage terminal 410 and the second AC voltage terminal 420 assists in filtering the AC voltage to be provided. In summary, the provision of electrical energy at the two-pole AC voltage terminal 400 is enabled.This two-pole AC voltage connection 400 is preferably provided via a socket, either internally or externally within the vehicle, preferably for supplying connected, preferably household, consumers 402. The electrical energy at the intermediate connection 300 can be provided by a power source connected to the input connection via a single- to three-phase supply and / or a battery 470 connected, preferably via the DC-DC converter 450. For this purpose, the DC-DC converter 450 is designed as a bidirectional DC-DC converter. The DC-DC converter 450 converts the DC voltage of the battery 470 into the desired DC voltage at the intermediate connection 300.

[0059] Figure 4 shows a schematic representation of an exemplary current or energy flow in a second operating mode of the circuit topology for a charger. To provide electrical energy at the intermediate terminal 300, an AC voltage provided at the input terminal unit 100 is preferably provided via the PFC stage 200, at least partially as a DC voltage, at the positive intermediate terminal 310 and the negative intermediate terminal 320. Preferably, a charging current is conducted via at least the first connecting line 110 and the second connecting line 120, or at least the second part of the second connecting line 120_2, via the PFC stage 200 to the intermediate terminal 300. Preferably, the entire charging current is filtered via the first and second capacitors C1, C2 and fed back to the neutral conductor terminal NI via the diode D2 and the neutral conductor 140.Preferably, a three-phase alternating current from a three-phase alternating voltage source connected to the input connection unit is conducted via all three connecting lines 110, 120, 130 with the first and third switching elements S1, S3 closed, via the first, second, and third chokes 202, 204, 206 to the intermediate connection. Preferably, a three-phase alternating current from a three-phase alternating voltage source connected to the input connection unit is conducted via the first and second connecting lines 110, 120 with the first switching element S1 closed and the third switching element S3 open, via the first and second chokes 202 and 204 to the intermediate connection. Due to the resulting asymmetrical loading of the charger 500, the connection between the center tap of the series connection of the first and second capacitors C1, C2 and the center tap of the series connection of the first and second diodes D1, D2 is preferably closed by means of the switching element S7.The closed switching element S7 enables an alternative path for returning the charging current, or the resulting current, via the neutral conductor 140. Preferably, a single-phase alternating current from a single-phase alternating voltage source connected to the input connection unit is conducted by means of a bridge 150, a galvanic connection, between the first, second and third input terminals LI, L2, L3 via all three connection lines 110, 120, 130 with the first and third switching elements S1 S3 closed via the first, second and third chokes 202, 204, 206 to the intermediate terminal.Preferably, a single-phase alternating current from a single-phase AC voltage source connected to the input connection unit is conducted to the intermediate connection by means of a bridge 150, a galvanic connection, between the first, second, and third input terminals L1, L2, L3 via the first and second connecting lines 110, 120 with the first S1 switching element closed and the third S3 switching element open, via the first and second chokes 202 and 204. Preferably, the bridge 150 is used in chargers 500 that are deployed in regions of the world where the infrastructure and the public power grid only provide single-phase AC voltage sources as external AC voltage sources.Preferably, a single-phase alternating current from a single-phase alternating voltage source connected to the first input terminal LI of the input terminal unit 100 is conducted to the intermediate terminal by means of the second switching element S2 via the first connecting line 110 and the second part of the second connecting line 120_2, with the first S1 closed, via the first and second chokes 202 and 204. In summary, different options for providing electrical energy at the intermediate terminal 300 are provided. These different options correspond to the current flow during charging operation, in which energy from an external energy source connected to the input terminal 100 is transferred to the intermediate terminal 300. Preferably, the second operating mode is implemented alone.When the second operating mode is available with the switching element S3 open, the first operating mode, the provision of electrical energy at the two-pole AC voltage connection 400, is preferably carried out simultaneously.

[0060] Figure 5 shows a schematic representation of an exemplary current or energy flow in a third operating mode of the circuit topology for a charger. Preferably, to provide electrical energy to the first input terminal LI and the neutral conductor terminal NI, a DC voltage provided at the positive intermediate terminal 310 and the negative intermediate terminal 320 is provided at least partially as an AC voltage at the first input terminal LI and the neutral conductor terminal 420. Preferably, a current is conducted between the positive intermediate terminal 310 and the first input terminal LI via the first half-bridge 210 and the first choke 202. Preferably, the first switching element S1 is closed for this purpose.A current between the negative intermediate terminal 320 and the neutral conductor terminal NI is conducted via the second half-bridge 220 and the second choke 204, wherein the fifth switching element S5 enables a current flow from the second choke 204 via the neutral conductor 140 to the neutral conductor terminal NI. Preferably, a third capacitor C3 between the first connecting line 110 and the neutral conductor 140 supports the filtering of the AC voltage to be provided. Preferably, the provided AC voltage is intended to supply typical household consumers. Typical household consumers are preferably supplied with an AC voltage which, depending on the region, is approximately 120 volts or 230-240 volts. In summary, a provision of electrical energy, a controllable AC voltage, is enabled at the first input terminal LI and the neutral conductor terminal NI.This electrical energy is preferably provided externally to the vehicle via a power outlet, preferably to supply additional connected, preferably household, consumers. The electrical energy at the intermediate connection 300 is provided for this purpose by a battery 470, preferably connected via the DC-DC converter 450. For this purpose, the DC-DC converter 450 is designed as a bidirectional DC-DC converter. The third operating mode is preferably implemented alone or simultaneously with the first operating mode.

[0061] Figure 6 shows a schematically illustrated vehicle 700 with a drive train 600 with a charger 500. The vehicle 700 is shown here only as an example with four wheels, whereby the invention can be used equally in any vehicle with any number of wheels on land, on water and in the air. The drive train 600 shown as an example comprises at least one charger 500. Furthermore, the drive train preferably comprises a battery 470, an inverter 472 and / or an electric machine 474. Figure 7 shows a schematically illustrated flow diagram for a method 800 for operating a charger 500. The method 800 starts with step 805. In step 810, the fourth and sixth switching elements S4, S6 as well as the high-side and low-side switches of the third and fourth half-bridges 210, 220, 230, 240 are used to provide electrical energy at the two-pole

[0062] AC voltage terminal 400 is controlled. The process ends with step 815.

Claims

Charger for a vehicle, wherein the charger (500) comprises on the input side an input connection unit (100) for connecting a single-phase or three-phase alternating voltage, a PFC stage (200) for providing a direct voltage at an intermediate connection (300) and a two-pole alternating voltage connection (400) for providing an alternating voltage, wherein the P FC stage (200) comprises a first (210), a second (220) and a third (230) half-bridge, wherein the first, second and third half-bridges (210, 220, 230) each comprise a series circuit with a high-side switch (211, 213, 215) and a low-side switch (212, 214, 216), wherein in each case a center tap is connected between the high-side switch and the low-side switch of a half-bridge via a respective first, second and third choke (202, 204, 206) each having a first, second and third input terminal (LI, L2, L3) of the input terminal unit (100) via a first,second and third connection lines (110, 120, 130) are connectable, wherein the half-bridges (210, 220, 230) are connected in parallel and their ends are connected to the two-pole intermediate connection (300), wherein the high-side switches are connected to a positive intermediate connection (310) and the low-side switches are connected to a negative intermediate connection (320), wherein the charger comprises a fourth half-bridge (240) which is connected in parallel to the first, second and third half-bridges (210, 220, 230), with a high-side switch (217) and a low-side switch (218), wherein a center tap between the high-side switch and the low-side switch of the fourth half-bridge (240) is connected via a sixth switching element (S6) to a second AC voltage connection (420) of the two-pole AC voltage connection (400) is switchably connected and wherein a fourth switching element (S4) is provided, which is designed toto establish a connection via the third choke (206) between the third half-bridge (230) and a first AC voltage terminal (410) of the two-pole AC voltage terminal (400) or a connection via the third choke (206) between the third half-bridge (230) and the third connection line (130) to the third input terminal (L3). Charger according to claim 1, wherein the input connection unit (100) further comprises a neutral conductor connection (NI), wherein a series circuit of a first (D1) and a second (D2) diode is connected in parallel to the half-bridges, wherein the first and the second diode (D1, D2) are connected in the reverse direction and prevent a current flow from the positive intermediate connection (310) to the negative intermediate connection (320) and enable a current flow from the negative intermediate connection (320) to the positive intermediate connection (310), wherein a center tap between the first and the second diode (D1, D2) is connected via a neutral conductor (140) to the neutral conductor connection (NI), wherein a series circuit of a first (C1) and a second (C2) capacitor is connected in parallel to the half-bridges (210, 220, 230), wherein a fifth switching element (S5) is provided, which is designed toto connect the second choke (204), which is connected on the one hand to the second half-bridge (220), either to the neutral conductor (140) or to the second connecting line (120) to the second input terminal (L2).

3. Charger according to claim 2, wherein the second connection line (120) is divided into a first part of the second connection line (120_l) and a second part of the second connection line (120_2), wherein a second switching element (S2) is provided which is arranged between the first part of the second connection line (120_l) and the second part of the second connection line (120_2) and is configured to conduct a charging current from the second input terminal (L2) via the first part and the second part of the second connection line (120_l, 120_2) to the second choke (204) or to conduct a charging current from the first connection line (110) via the second part of the second connection line (120_2) to the second choke (204).

4. Charger according to one of the preceding claims, wherein a first switching element (S1) is provided and configured to enable or interrupt a current flow between the first input terminal (LI) and the first connecting line (110).

5. The charger according to one of claims 2 to 4, wherein a third switching element (S3) is provided and configured to enable or interrupt a charging current between the third input terminal (L3) and the third connecting line (130). The charger according to one of claims 2 to 5, wherein a seventh switching element (S7) is arranged between the center tap between the first and second diodes (D1, D2) and a center tap between the first and second capacitors (C1, C2).

7. Charger according to one of the preceding claims, wherein, in order to provide electrical energy at the two-pole AC voltage connection (400), a DC voltage provided at the positive intermediate connection (310) and at the negative intermediate connection (320) is provided at least partially as AC voltage at the first AC voltage connection (410) and at the second AC voltage connection (420), wherein the fourth switching element (S4) establishes a connection from the center tap of the third half-bridge (230) via the third choke (206) to the first AC voltage connection (410) and the sixth switching element (S6) establishes a connection from the center tap of the fourth half-bridge (240) to the second AC voltage connection (420).

8. Charger according to one of claims 2 to 7, wherein for providing electrical energy at the intermediate terminal (300) - either an alternating voltage provided at the input terminal unit (100) is provided via the PFC stage (200) at least partially as a direct voltage at the positive intermediate terminal (310) and at the negative intermediate terminal (320), wherein a charging current is conducted via at least the first connecting line (110) and the second connecting line (120), or at least the second part of the second connecting line (120_2), via the P FC stage (200) to the intermediate connection (300) and preferably the entire charging current is returned via the neutral conductor (140), - or a DC voltage provided by a bidirectional DC-DC converter (550) connected to the intermediate terminal (300) and a battery (560) connected thereto is provided at the positive intermediate terminal (310) and at the negative intermediate terminal (320), wherein for this purpose the bidirectional DC-DC converter converts the voltage of the traction battery to the DC voltage to be provided at the positive intermediate terminal (310) and at the negative intermediate terminal (320).Charger according to one of claims 2 to 8, wherein the charger (500) is configured to provide an alternating voltage at the input connection unit (100) at the first input connection (LI) and the neutral conductor connection (NI), wherein, in order to provide electrical energy at the first input connection (LI) and the neutral conductor connection (NI), a direct voltage provided at the positive intermediate connection (310) and at the negative intermediate connection (320) is provided at least partially as an alternating voltage at the first input connection (LI) and at the neutral conductor connection (420), wherein a current between the positive intermediate connection (310) and the first input connection (LI) is conducted via the first choke (202) and a current between the negative intermediate connection (320) and the neutral conductor connection (NI) is conducted via the second choke (204).Drivetrain (600) of a vehicle (700) with a charging device (500) according to one of the preceding claims, wherein the drivetrain (600) comprises in particular a traction battery (470), an inverter (472), and / or an electric machine (474). Vehicle (700) with a drivetrain (600) according to claim 10. Method (800) for operating a charger according to one of claims 1 to 9, comprising the step: Controlling (810) the fourth and sixth switching elements (S4) and (S6) as well as the high-side and low-side switches of the third and fourth half-bridges (210, 220, 230, 240) to provide electrical energy at the two-pole AC voltage connection (400). A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method (800) according to claim 12. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the method (800) according to claim 12.

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