Charging device and method for operating a charging device

Abstract

The invention relates to a charging device for a vehicle, said charging device (500) comprising, on the input side, an input connection unit (100) for connecting a single-phase or three-phase AC voltage, a PFC stage (200) for providing a DC voltage at an intermediate connection (300), and a bipolar AC voltage connection (400) for providing an AC voltage.

Description

Technical Field

[0001] The invention relates to a charging appliance and a method for operating a charging appliance. The invention also relates to a drive train with a charging appliance, a vehicle with a drive train, and a computer program and a machine-readable storage medium. Background Art

[0002] For example, in vehicles with an electric drive, in electric vehicles or hybrid vehicles, charging devices are used to recharge batteries, preferably storage batteries or traction batteries, from an electrical energy source, preferably an external alternating current source or a public alternating current network. To this end, the charging device converts the sinusoidal alternating current of the external energy source into direct current. In single-phase alternating current, the power pulsates at twice the frequency of the alternating current.

[0003] The charger preferably has two-stage power electronics. The first stage, the so-called power factor correction stage, i.e., the PFC stage, converts the sinusoidal input voltage from the AC voltage network into a DC voltage. The second stage consists of a DC voltage converter or a DC / DC converter, which ensures electrical isolation and adapts the voltage level through a transformer. The output voltage and / or output current for charging the battery are preferably set by means of circuits and adjustments. An intermediate circuit capacitor is arranged between the two stages, which buffers power pulsations with a frequency twice that of the AC current of the energy source. Typically, the intermediate circuit is realized by at least one electrolytic capacitor. The topology enables: maintaining an almost sinusoidal input current on the network side to meet the standards on the network side, electrically isolating the network from the vehicle to meet safety requirements, and providing a constant output DC current on the battery side to minimize the load on the battery during charging operation.

[0004] In a vehicle with an electric drive, the battery is also connected to an inverter for supplying energy to the electric drive. A DC voltage converter is connected in parallel with the inverter for supplying the low-voltage network or the onboard power grid of the vehicle for supplying energy to the controller. It is known that an AC voltage is generated by means of an inverter connected to the onboard power grid in order to supply energy to the AC voltage socket inside the vehicle. The AC voltage socket is provided for operating household electrical appliances commonly used in the vehicle. Common household electrical appliances are, for example, media players, computers, charging devices for mobile devices, refrigerators or coffee machines. The multiple transformers obtained in the vehicle are complex and require a lot of space in the vehicle. Therefore, there is a demand for a simple, compact and efficient solution for providing multiple required voltages. Summary of the invention

[0005] A charging device for a vehicle is provided, wherein the charging device comprises, on the input side, a preferably three-phase input connection unit for connecting a single-phase to three-phase AC voltage, a PFC stage for providing a DC voltage at an intermediate connection, and a bipolar AC voltage connection for providing an AC voltage. The PFC stage comprises a first, a second and a third half bridge. The first, the second and the third half bridges each comprise a series circuit having a high side switch and a low side switch. The center taps between the high side switch and the low side switch of the half bridge can be connected to the first, the second and the third input connections of the preferably three-phase input connection unit through the first, the second and the third connecting wires respectively through the first, the second and the third choke valves. Therefore, the center tap of the first half bridge can be connected to the first input connection through the first choke valve through the first connecting wire. Therefore, the center tap of the second half bridge can be connected to the second input connection through the second choke valve through the second connecting wire. Therefore, the center tap of the third half bridge can be connected to the third input connection through the third choke valve through the third connecting wire. These half bridges are connected in parallel and their ends are connected to the bipolar intermediate connection. The high side switch is connected to the positive middle terminal of the bipolar middle terminal and the low side switch is connected to the negative middle terminal thereof. The charger comprises a fourth half bridge, which is connected in parallel with the first, second and third half bridges. The fourth half bridge comprises a high side switch and a low side switch, wherein the middle tap between the high side switch and the low side switch of the fourth half bridge is connected to the second AC voltage terminal of the bipolar AC voltage terminal in a switchable manner through a sixth switching element. A fourth switching element, preferably a fourth switch, is provided and is configured to establish a connection between the third half bridge and the first AC voltage terminal of the bipolar AC voltage terminal through a third throttle valve, or to establish a connection between the third half bridge and the third connecting wire to the third input terminal through a third throttle valve. Further advantageously, the third connecting wire can be decoupled from the PFC stage and thus from the first and second capacitors by means of the fourth switching element. Preferably, the third connecting wire is therefore connected to the PFC stage only after the first and second capacitors are charged. Preferably, the current is prohibited from being connected when the third connecting wire is connected. Preferably, the pre-charging resistor between the third input terminal and the third connecting wire can be omitted.

[0006] Preferably, when operating a bipolar AC voltage connection, the electrical energy applied to the intermediate connection is provided at the bipolar AC voltage connection. The electrical energy at the intermediate connection is preferably provided by an external energy source, or infrastructure or EVSE (Electric Vehicle Supply Equipment) via an input connection unit and a PFC stage, or by a battery connected to a charger, preferably a traction battery of the vehicle, via a bidirectional DC / DC converter connected to the intermediate connection.

[0007] In order to provide a bipolar AC voltage connection at which an adjustable AC voltage can be provided, a fourth half-bridge is added to the PFC stage of the charging device, wherein the center tap thereof leads to the second AC voltage connection. The first AC voltage connection is connected to the center tap of the third half-bridge of the PFC stage via the third throttle of the PFC stage. Advantageously, a circuit for the charging device is provided so that an adjustable AC voltage can be provided at the bipolar AC voltage connection. During the charging process for charging the battery, the AC voltage can be provided by means of the charging device. Preferably, the DC voltage at the center connection is converted into the desired AC voltage by means of the third and fourth half-bridges. Preferably, even during the charging process of the battery, the voltage and current at the electrical appliances connected to the bipolar AC voltage connection can be influenced by the charging device. Preferably, an overload of an external energy source can be prevented by the targeted disconnection of the high-side switch and the low-side switch of the third and fourth half-bridges and the disconnection of the connected electrical appliances thereby achieved. Preferably, the charging device and / or the connected electrical appliances can be protected by overcurrent shutdown in the event of a short circuit.

[0008] The external energy source is preferably a single-phase, two-phase or three-phase AC voltage network of a preferably public low-voltage network. Preferably, this is a single-phase AC voltage network with 120 or 240 volts in North America or Japan. Preferably, this is a three-phase AC voltage network with about 230 volts in China or Europe. For the charging operation of the charging device, the charging device is connected to the corresponding AC voltage network or to the corresponding AC voltage. The battery to be charged is preferably a storage battery or a traction battery, with the help of its energy to operate the electric drive system of the vehicle. The rectifier circuit is preferably a rectifier for converting AC current into DC current. The high-side switch or low-side switch of the semiconductor bridge is preferably a power semiconductor switch, which includes an inherent diode, preferably an IGBT or MOSFET, preferably based on silicon, silicon carbide or gallium nitride technology. Preferably, the term "connection" of the center tap and the connecting wire means connecting, contacting or connecting components by means of a conductive line or electrical connection. The terms "blocking", "preventing", "decoupling" or "blocking current" mean isolating a line or connection that can conduct electricity. The term "connected" is preferably used synonymously with electrical connection, wherein "connected in a switchable manner" means that an electrical connection can be established or can be isolated, preferably by means of a switch or switching element. The term "arranged" is preferably used to specify the position of an electrical component, preferably a switch or switching element, within a circuit topology, wherein this includes electrical connections to electrical components arranged next to it.

[0009] In another embodiment, the input connection unit includes a neutral connection. The first to fourth half bridges are connected in parallel with a series circuit of a first and a second diode. The first and second diodes are connected in a cut-off direction and prevent, cut off or block the current from the positive intermediate connection to the negative intermediate connection, and can realize the current from the negative intermediate connection to the positive intermediate connection. The center tap between the first and second diodes is connected to the neutral connection via a neutral line. These half bridges are connected in parallel with a series circuit consisting of a first and a second capacitor. A fifth switching element is also provided, which is set to connect the second throttle valve connected to the second half bridge to the second input connection either to the neutral line or to the second connecting wire.

[0010] The fifth switching element, preferably the fifth switch, is arranged between the second throttle valve and the second connecting wire. Depending on the switching position, the second throttle valve is connected to the neutral line or to the second connecting wire toward the second input connection. Advantageously, a feasible solution is implemented, namely: an AC voltage is provided at the first input connection and the neutral connection at the input connection unit. Preferably, the DC voltage at the intermediate connection is converted into the desired AC voltage by means of the first and second half-bridges, and is provided as an AC voltage at the first input connection and the neutral connection. Here, the electrical energy at the intermediate connection is preferably provided by a battery connected to the charger, preferably a traction battery of the vehicle, through a bidirectional DC / DC converter connected to the intermediate connection.

[0011] In another embodiment of the present 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 designed to guide the charging current from the second input connection through the first part and the second part of the second connecting line to the second choke valve, or to guide the charging current from the first connecting line through the second part of the second connecting line to the second choke valve.

[0012] The second switching element, preferably the second switch, is arranged between the first part of the second connecting line and the second part of the second connecting line. According to the switching position of the second switching element, the charging current is thus guided from the second input connection through the first part and the second part of the second connecting line to the second choke valve, or the charging current is guided from the first connecting line through the second part of the second connecting line to the second choke valve. Advantageously, a feasible scheme is realized, that is, the single-phase charging current flowing through the first connecting line is partially bifurcated and guided to the second choke valve and the second half-bridge through the second part of the second connecting line. Therefore, it is preferably possible to reduce the load of the first choke valve and the first half-bridge when there is a single-phase charging current. When a single-phase AC voltage is connected to the input connection, a single-phase charging current is preferably obtained. It is also advantageous that 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. It is preferred that the first part of the second connecting line is connected to the PFC stage only after the first and second capacitors are charged (Aufladen). It is preferred that the current is prohibited from being connected when the first part of the second connecting line is connected. Preferably, a precharging resistor between the second input connection and the first section of the second connecting line can be omitted. Preferably, a short circuit between the first connecting line and the first section of the second connecting line is prevented due to the design of the second switching element as a second switch. Preferably, a short circuit between the first input connection and the second input connection can occur due to erroneous actuation of a simple switching element, and this fault situation can be reliably eliminated during actuation by means of the second switch.

[0013] In a further refinement, a first switching element is provided and is designed to enable or interrupt a current flow between the first input connection and the first connecting line or the first throttle of the PFC stage.

[0014] The first switching element is arranged between the first connecting line and the first input connection. Depending on the switching position, a current or charging current from the first input connection in the direction of the first throttle valve of the PFC stage can be achieved or prevented. Advantageously, a feasible solution is achieved, namely: interrupting or connecting the charging current through the first connecting line. Preferably, a thermal conductor or a negative temperature coefficient resistor is connected in parallel to the first switching element, which is used to limit the connection current. Preferably, the connection current flows from the first input connection through the PFC stage into the first and / or second capacitor. Preferably, at low temperatures, the resistance of the thermal conductor is higher and the connection current is reduced. After connection, the thermal conductor heats up due to the current and loses its high initial resistance. Preferably, in order to reduce the losses of the thermal conductor, this is eliminated by closing the first switching element when the first and / or second capacitor is basically filled (aufladen).

[0015] In a further refinement, a third switching element is provided and is designed to enable or interrupt a charging current between the third input connection and a third connecting line or a third throttle of the PFC stage.

[0016] The third switching element is arranged between the third connecting wire and the third input connection. Depending on the switching position, a current or charging current from the third input connection in the direction of the third throttle valve of the PFC stage can be achieved or prevented. Advantageously, a feasible solution is achieved, namely: preferably in the presence of a three-phase charging current, the charging current is interrupted or connected through the third connecting wire. Preferably, the third switching element is connected in parallel with a thermal conductor or a negative temperature coefficient resistor, which is used to limit the connection current. Preferably, the connection current flows from the third input connection through the PFC stage into the first and / or second capacitor. Preferably, the resistance of the thermal conductor is higher at low temperatures and the connection current is reduced. After connection, the thermal conductor heats up due to the current and loses its high initial resistance. Preferably, in order to reduce the losses of the thermal conductor, this is eliminated by closing the third switching element when the first and / or second capacitor is basically full.

[0017] In a further refinement, the seventh switching element is arranged between a center tap between the first and second diodes and a center tap between the first and second capacitors.

[0018] The 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. According to the switching position, the current between the center taps of the diode series circuit and the capacitor series circuit can be realized or prevented. A feasible scheme is advantageously implemented, that is, preferably in the case of a two-phase or three-phase charging current, the current is interrupted or connected 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 the operation of the charging device with an asymmetric load. Asymmetric loads exist when running with a 2-phase network, or in asymmetric loads when running with a 3-phase network, that is, in the case of a two-phase or three-phase AC voltage. In these cases, the current generated by the closed seventh switching element flows on the zero line. In the case of a symmetrical load, the AC voltage is the same on the first, second and third connecting wires, and the mutual phase offset of the AC voltage is 120 degrees respectively. In this case, the sum of the phase currents and the current generated on the zero line are equal to zero. In the case of an asymmetrical load, the AC voltages on the first, second and third connecting conductors are not all of the same magnitude and / or the phase shift of the AC voltages relative to each other is not 120 degrees. In this case, the sum of the phase currents and the resulting current is not equal to zero. Preferably, when the switching element is closed, a current flow for this total current can be achieved via the neutral-to-neutral connection.

[0019] In another embodiment, in order to provide electrical energy at a bipolar AC voltage connection, a DC voltage provided at a positive intermediate connection and at a negative intermediate connection is at least partially provided as an AC voltage at a first AC voltage connection and at a second AC voltage connection, wherein a fourth switching element establishes a connection from a center tap of a third half-bridge via a third throttle valve to the first AC voltage connection, and a sixth switching element establishes a connection from a center tap of a fourth half-bridge to the second AC voltage connection.

[0020] Advantageously, the fourth and sixth switching elements are switched in such a way that a regulated AC voltage can be provided at the bipolar AC voltage connection. The DC voltage at the intermediate connection is converted into the desired AC voltage by means of the third and fourth half-bridges, preferably by means of filtering, via the third throttle valve and the fourth capacitor between the first and second AC voltage connections. The third and fourth half-bridges thus act like inverters in order to generate a preferably single-phase AC voltage at the bipolar AC voltage connection from the DC voltage.

[0021] In another embodiment, in order to provide electrical energy at the intermediate connection

[0022] - either the AC voltage provided at the input connection unit is provided at least partially as a DC voltage at the positive intermediate connection and at the negative intermediate connection via the PFC stage, wherein the charging current is conducted via at least the first connecting line and the second connecting line or at least via the second part of the second connecting line via the PFC stage to the intermediate connection, and preferably the entire charging current is conducted back via the neutral conductor,

[0023] Either a DC voltage is provided at a positive and at a negative central terminal based on a bidirectional DC voltage converter connected to the central terminal and a battery connected thereto, preferably a traction battery, wherein for this purpose the bidirectional DC voltage converter converts the battery voltage into a DC voltage to be provided at the positive and at the negative central terminal.

[0024] Advantageously, a topology is provided which makes it possible to provide a DC voltage at a central terminal, wherein the energy for this purpose can be provided on the one hand by an external energy source or by a battery, preferably within the vehicle.

[0025] In one embodiment, the charging device is configured to provide an AC voltage at a first input connection and a neutral connection at an input connection unit, wherein, in order to provide electrical energy at the first input connection and at the neutral connection, a DC voltage provided at a positive intermediate connection and at a negative intermediate connection is at least partially provided as an AC voltage at the first input connection and at the neutral connection, wherein the current between the positive intermediate connection and the first input connection is conducted through a first choke valve, and the current between the negative intermediate connection and the neutral connection is conducted through a second choke valve.

[0026] Advantageously, a topology is provided which makes it possible to provide an AC voltage at the first input connection and the neutral connection, wherein the energy for this purpose is provided by a battery, preferably within the vehicle.

[0027] The invention further relates to a drive train of a vehicle having a charging device 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 having a charging device with a simplified circuit topology is provided.

[0028] The invention further relates to a vehicle having a drive train as described above. Advantageously, a vehicle having a charging device with a simplified circuit topology is provided.

[0029] Furthermore, the invention relates to a method for operating a charging appliance as envisaged above, the method comprising the step of actuating a fourth and a sixth switching element and a high-side and a low-side switch of a third and a fourth half-bridge in order to provide electrical energy at a bipolar AC voltage connection.

[0030] By controlling the switches of the third and fourth half-bridges and closing the fourth and sixth switching elements, the DC voltage applied to the intermediate terminal is converted into an AC voltage, which is applied to the bipolar AC voltage terminal. Advantageously, a method is provided, by which a regulated AC voltage can be provided at the bipolar AC voltage terminal.

[0031] Furthermore, the invention relates to a computer program which comprises instructions which, when the program is executed by a computer, cause the computer to carry out the described method.

[0032] Furthermore, the invention relates to a computer-readable storage medium which comprises instructions which, when executed by a computer, cause the computer to carry out the described method.

[0033] It goes without saying that the features, properties and advantages of the charging appliance are correspondingly applicable or can be used for the method and the drive train and the vehicle, and vice versa.

[0034] Further features and advantages of embodiments of the invention emerge from the following description with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The invention will be explained in more detail below with reference to some figures, for which the following is shown:

[0036] Figure 1 A schematic diagram showing an embodiment known from the prior art of a circuit topology for a charging appliance,

[0037] Figure 2 A schematic diagram showing a first embodiment of a circuit topology for a charging appliance,

[0038] Figure 3 shows a schematic diagram of an exemplary current or energy flow in a first operating mode of a circuit topology for a charging appliance,

[0039] Figure 4 shows a schematic diagram of an exemplary current or energy flow in a second operating mode of a circuit topology for a charging appliance,

[0040] Figure 5 shows a schematic diagram of an exemplary current or energy flow in a third operating mode of a circuit topology for a charging appliance,

[0041] Figure 6 shows a schematically illustrated vehicle having a drive train with a charging device,

[0042] Figure 7 A schematically illustrated flow chart of a method for operating a charging appliance is shown. DETAILED DESCRIPTION

[0043] Figure 1A charging device 500 preferably for a vehicle is shown. The charging device 500 comprises an input connection unit 100 for connecting a single-phase to three-phase AC voltage on the input side, and a PFC stage 200 for providing a DC voltage at an intermediate connection 300. The PFC stage 200 of the charging device 500 comprises a first half bridge 210, a second half bridge 220 and a third half bridge 230. The first, second and third half bridges 210, 220, 230 respectively comprise a series circuit with a high side switch 211, 213, 215 and a low side switch 212, 214, 216. The center taps between the high side switches and the low side switches of the half bridges can be connected to the first, second and third input connections L1, L2, L3 of the input connection unit 100 respectively via the first, second and third connecting wires 110, 120, 130 respectively through the first, second and third throttle valves 202, 204, 206. Thus, the center tap of the first half-bridge 210 can be connected to the first input connection L1 via the first throttle valve 202 via the first connecting line 110. Thus, the center tap of the second half-bridge 220 can be connected to the second input connection L2 via the second throttle valve 204 via the second connecting line 120. Thus, the center tap of the third half-bridge 230 can be connected to the third input connection L3 via the third throttle valve 206 via the third connecting line 130. The half-bridges 210, 220, 230 are connected in parallel. Their ends are connected to a bipolar center connection 300. The high-side switch is connected to the positive center connection 310 and the low-side switch is connected to the negative center connection 320. Preferably, a DC voltage converter 450 is connected to the center connection 300. The DC voltage at the center connection 300 is applied to the DC voltage converter 450 on the input side, which DC voltage is preferably converted into a charging voltage for charging a battery 470, preferably a traction battery or a high-voltage battery, which can be connected on the output side of the DC voltage converter 450. Preferably, another DC voltage converter 460, preferably a step-down chopper, is connected in parallel with the battery 470 to convert the charging voltage into a low voltage for charging the low-voltage battery 462 and for supplying the vehicle's onboard power grid to supply the vehicle's controller. As preferably there are other low-voltage electrical appliances not shown, the low-voltage battery 462 is connected to the vehicle's onboard power grid. Preferably, the other DC voltage converter 460 is a bidirectional DC voltage converter. Preferably, before the battery 470 is connected to the charger 500, the other DC voltage converter 460 can be used to pre-charge the high-voltage intermediate circuit. The high-voltage intermediate circuit is located at the DC voltage converter 450 on the output side. Preferably, an inverter 480 is connected to the onboard power grid, which converts the low voltage into an AC voltage for supplying electrical appliances commonly used in households. Preferably, electrical appliances commonly used in households are supplied with an AC voltage, which is different according to the region, about 120 volts or 230-240 volts. For this purpose, an AC voltage consumer can be connected to the first connection pole 482 and to the second connection pole 484 .

[0044] From the basis Figure 1 Starting from the charging device 500 of the present invention, the charging device 500 according to the present invention Figure 2 A two-pole AC voltage connection 400 is included.

[0045] In order to provide an AC voltage at the AC voltage connection 400, the charging device 500 comprises a fourth half bridge 240 which is connected in parallel with the first, second and third half bridges 210, 220, 230 and has 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 the second AC voltage connection 420 of the bipolar AC voltage connection 400 via a sixth switching element S6, and wherein a fourth switching element S4 is provided which is designed to establish a connection between the third half bridge 230 and the first AC voltage connection 410 via a third throttle valve 206 or a connection to the third input connection L3 via a third throttle valve 206 between the third half bridge 230 and the third connecting line 130. Preferably, the bipolar AC voltage connection is designed to supply household electrical appliances during operation. Preferably, household electrical appliances are supplied with an AC voltage which varies depending on the region and is approximately 120 volts or 230-240 volts.

[0046] Preferably, the input connection unit 100 also includes a neutral connection N1. The half bridges 210, 220, 230, 240 are connected in parallel with a series circuit of a first diode D1 and a second diode D2. The first and second diodes D1, D2 are connected in a cut-off direction and prevent the current from the positive intermediate connection 310 to the negative intermediate connection 320, and can realize the current from the negative intermediate connection 320 to the positive intermediate connection 310. The center tap between the first and second diodes D1, D2 is connected to the neutral connection N1 through the neutral line 140. The half bridges 210, 220, 230, 240 are connected in parallel with a series circuit consisting of a first capacitor C1 and a second capacitor C2. A fifth switching element S5 is provided and is set to, on the one hand, connect the second throttle valve 204 connected to the second half bridge 220 to the neutral line 140 or to the second connecting wire 120 toward the second input connection L2.

[0047] Preferably, the second connecting line 120 is divided into a first part 120_1 of the second connecting line and a second part 120_2 of the second connecting line. In addition, a second switching element S2 is provided, which is arranged between the first part 120_1 of the second connecting line and the second part 120_2 of the second connecting line. The second switching element S2 is designed to conduct a charging current from the second input connection L2 through the first and second parts 120_1, 120_2 of the second connecting line to the second throttle valve 204, or to conduct a charging current from the first connecting line 110 through the second part 120_2 of the second connecting line to the second throttle valve 204.

[0048] A first switching element S1 is preferably provided and is designed to enable or interrupt a current flow between the first input connection L1 and the first connecting line 110 .

[0049] A third switching element S3 is preferably provided and is designed to enable or interrupt a charging current between the third input connection L3 and the third connecting line 130 .

[0050] Preferably, the first switching element S1 and the third switching element S3 are connected in parallel with a precharging resistor, preferably a switchable resistor, a thermal conductor or a negative temperature coefficient resistor, so that the starting current when the AC voltage is connected to the input connection unit 100 is attenuated and limited before the first and third switching elements S1, S3 are closed.

[0051] The seventh switching element S7 is preferably arranged between a center tap between the first and second diodes D1 , D2 and a center tap between the first and second capacitors C1 , C2 .

[0052] Preferably, a current sensor (A) is arranged at the first, second and third throttle valves 202, 204, 206, respectively, for determining the current through the corresponding throttle valves 202, 204, 206. The high-side switch and the low-side switch and the switching element are preferably controlled according to the current determined to perform the desired operating mode. Preferably, a voltage sensor (V) is arranged between the first, second and third connecting wires 110, 120, 130 and the neutral line 140, respectively, for determining the voltage. Preferably, a voltage sensor (V) is also arranged between 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, respectively. The high-side switch and the low-side switch and the switching element are preferably controlled according to the voltage determined to perform the desired operating mode. Preferably, the negative intermediate terminal 320 is connected to the ground GND AC. Preferably, GND AC is an internal potential.

[0053] The switching elements are preferably designed as semiconductor switching components (IGBTs or MOSFETS based on silicon, silicon carbide or gallium nitride) or as contactors or relays.

[0054] Figure 3 A schematic diagram of an exemplary current or energy flow in the case of a first operating mode of a circuit topology for a charging device 500 is shown. Preferably, in order to provide electrical energy at a bipolar AC voltage connection 400, the DC voltage provided at the positive intermediate connection 310 and at the negative intermediate connection 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. Preferably, for this purpose, the fourth switching element S4 establishes a connection from the center tap of the third half bridge 230 via the third throttle valve 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. Thus, Figure 3 : from the positive central connection 310 through the third half bridge 230 and the third throttle valve 206 through the fourth switching element S4, preferably through the filter 404, preferably an EMC filter to the first AC voltage connection 410, and from the second AC voltage connection 420 through the closed switching element S6 back through the fourth half bridge 240 to the negative central connection 320. Preferably, the fourth capacitor C4 between the first AC voltage connection 410 and the second AC voltage connection 420 supports the filtering of the AC voltage to be provided. In summary, electrical energy can be provided at a bipolar AC voltage connection 400. Such a bipolar AC voltage connection 400 is preferably provided inside the vehicle or outside the vehicle by means of a socket, preferably for supplying a connected, preferably household electrical appliance 402. In this case, the electrical energy at the central connection 300 can be provided based on an energy source connected to the input connection in a single-phase to three-phase manner and / or based on a battery 470 preferably connected via a DC voltage converter 450. For this purpose, the DC voltage converter 450 is designed as a bidirectional DC voltage converter, wherein the DC voltage converter 450 converts the DC voltage of the battery 470 into the desired DC voltage at the intermediate terminal 300 .

[0055] Figure 4A schematic diagram of an exemplary current or energy flow in the second operating mode of the circuit topology for charging a device is shown. Preferably, in order to provide electrical energy at the intermediate terminal 300, the AC voltage provided at the input terminal unit 100 is provided at least partially as a DC voltage at the positive intermediate terminal 310 and at the negative intermediate terminal 320 via the PFC stage 200. Preferably, the charging current is conducted to the intermediate terminal 300 via at least the first connecting line 110 and the second connecting line 120, or at least via the second part 120_2 of the second connecting line, via the PFC stage 200. Preferably, the entire charging current is filtered via the first and second capacitors C1, C2 and is returned to the neutral terminal N1 via the diode D2 and the neutral line 140. Preferably, the three-phase AC current of the three-phase AC voltage source connected to the input terminal unit is conducted to the intermediate terminal via all three connecting lines 110, 120, 130 via the first, second and third throttle valves 202, 204, 206 when the first and third switching elements S1, S3 are closed. The three-phase alternating current of the three-phase alternating voltage source preferably connected to the input connection unit is conducted to the central connection via the first and second connecting lines 110, 120 through the first and second throttle valves 202 and 204 when the first switching element S1 is closed and the third switching element S3 is open. Due to the asymmetrical load generated by the charging device 500, the connection between the center tap of the series circuit of the first and second capacitors C1, C2 and the center tap of the series circuit 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 generated current via the neutral line 140. The single-phase alternating current of the single-phase alternating voltage source preferably connected to the input connection unit is conducted to the central connection via the bridge 150 between the first, second and third input connections L1, L2, L3, the electrical connection through all three connecting lines 110, 120, 130 through the first, second and third throttle valves 202, 204, 206 when the first and third switching elements S1, S3 are closed. The single-phase AC current of the single-phase AC voltage source preferably connected to the input connection unit is conducted to the intermediate connection by means of a bridge 150 between the first, second and third input connections L1, L2, L3, electrically connected via the first and second connecting lines 110, 120, when the first switching element S1 is closed and the third switching element S3 is open, via the first and second throttle valves 202 and 204. The bridge 150 is preferably used in a charging appliance 500, which is used in areas of the world where infrastructure and public power grids provide only single-phase AC voltage sources as external AC voltage sources.The single-phase AC current of the single-phase AC voltage source preferably connected to the first input connection L1 of the input connection unit 100 is guided to the intermediate connection by means of the second switching element S2 through the first connecting wire 110 and the second part 120_2 of the second connecting wire through the first and second throttle valves 202 and 204 when the first switching element S1 is closed. In summary, different feasible schemes are provided for providing electrical energy at the intermediate connection 300. These different feasible schemes correspond to the current trend in the case of charging operation, in which the energy of the external energy source connected to the input connection 100 is transferred to the intermediate connection 300. The second operating mode is preferably implemented separately. In the feasible scheme of the second operating mode with the disconnected switching element S3, the first operating mode is preferably implemented at the same time, and electrical energy is provided at the bipolar AC voltage connection 400.

[0056] Figure 5 A schematic diagram of an exemplary current or energy flow in the case of a third operating mode of a circuit topology for charging a device is shown. Preferably, in order to provide electrical energy at the first input connection L1 and the neutral connection N1, the DC voltage provided at the positive intermediate connection 310 and at the negative intermediate connection 320 is at least partially provided as an AC voltage at the first input connection L1 and at the neutral connection 420. Preferably, the current between the positive intermediate connection 310 and the first input connection L1 is conducted through the first half bridge 210 and the first choke 202. Preferably, the first switching element S1 is closed for this purpose. The current between the negative intermediate connection 320 and the neutral connection N1 is conducted through the second half bridge 220 and the second choke 204, wherein the fifth switching element S5 can realize the current from the second choke 204 through the neutral line 140 to the neutral connection N1. Preferably, the third capacitor C3 between the first connecting wire 110 and the neutral line 140 supports filtering the AC voltage to be provided. Preferably, the provided AC voltage is provided for supplying common household electrical appliances. Preferably, household electrical appliances are supplied with an AC voltage, which is different depending on the region and is about 120 volts or 230-240 volts. In summary, electrical energy and adjustable AC voltage can be provided at the first input connection L1 and the neutral connection N1. Preferably, the electrical energy is provided outside the vehicle by means of a socket, preferably for supplying other electrical appliances connected, preferably commonly used in households. For this purpose, the electrical energy at the intermediate connection 300 is provided based on a battery 470 preferably connected via a DC voltage converter 450. For this purpose, the DC voltage converter 450 is designed as a bidirectional DC voltage converter. Preferably, the third operating mode is implemented separately or simultaneously with the first operating mode.

[0057] Figure 6A schematically illustrated vehicle 700 is shown, which has a drive train 600 with a charging device 500. The vehicle 700 is shown here only by way of example with four wheels, wherein the invention can also be used in any vehicle with any number of wheels on land, on water, and in the air. The drive train 600 shown by way of example comprises at least the charging device 500. The drive train preferably also comprises a battery 470, an inverter 472 and optionally an electric motor 474.

[0058] Figure 7 A schematically illustrated flow chart of a method 800 for operating a charging device 500 is shown. The method 800 begins with step 805. In step 810, the fourth and sixth switching elements S4, S6 and the high-side and low-side switches of the third and fourth half bridges 210, 220, 230, 240 are actuated to provide electrical energy at the bipolar AC voltage connection 400. The method ends with step 815.

Claims

1. Charging equipment for vehicles, in, The charger (500) comprises, on the input side, an input connector unit (100) for connecting a single-phase or three-phase AC voltage, a PFC stage (200) for providing a DC voltage at an intermediate connector (300), and a bipolar AC voltage connector (400) for providing an AC voltage. The PFC stage (200) comprises a first half bridge (210), a second half bridge (220) and a third half bridge (230), The first, second and third half bridges (210, 220, 230) respectively comprise a series circuit having a high side switch (211, 213, 215) and a low side switch (212, 214, 216), wherein the center taps between the high side switch and the low side switch of the half bridges can be connected to the first, second and third input terminals (L1, L2, L3) of the input terminal unit (100) respectively through the first, second and third connecting wires (110, 120, 130) respectively through the first, second and third throttle valves (202, 204, 206), wherein the half bridges (210, 220, 230) are connected in parallel and their ends are connected to the bipolar intermediate terminal (300), wherein the high side switch is connected to the positive intermediate terminal (310) and the low side switch is connected to the negative intermediate terminal (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) and has 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 to a second AC voltage terminal (420) of the bipolar AC voltage terminal (400) in a switchable manner via a sixth switching element (S6), and A fourth switching element (S4) is provided, which is configured to establish a connection between the third half-bridge (230) and the first AC voltage connection (410) of the bipolar AC voltage connection (400) via the third throttle valve (206), or to establish a connection between the third half-bridge (230) and the third connecting line (130) to a third input connection (L3) via the third throttle valve (206).

2. The charging device according to claim 1, wherein: The input connector unit (100) further comprises a neutral line connector (N1), The half bridge is connected in parallel with a series circuit of a first diode (D1) and a second diode (D2), wherein the first and second diodes (D1, D2) are connected in a cut-off direction and block a current from the positive intermediate terminal (310) to the negative intermediate terminal (320), and enable a current from the negative intermediate terminal (320) to the positive intermediate terminal (310), wherein a center tap between the first and second diodes (D1, D2) is connected to the neutral terminal (N1) via a neutral line (140), The half bridge (210, 220, 230) is connected in parallel with a series circuit consisting of a first capacitor (C1) and a second capacitor (C2), A fifth switching element (S5) is provided, which is designed to connect a second throttle valve (204) connected to the second half bridge (220) either to the neutral line (140) or to the second connecting line (120) to the second input connection (L2).

3. The charging device according to claim 2, in, The second connecting wire (120) is divided into a first portion (120_1) of the second connecting wire and a second portion (120_2) of the second connecting wire, A second switching element (S2) is provided, which is arranged between a first part (120_1) of the second connecting line and a second part (120_2) of the second connecting line and is designed to guide a charging current from the second input connection (L2) through the first and second parts (120_1, 120_2) of the second connecting line to the second throttle valve (204), or to guide a charging current from the first connecting line (110) through the second part (120_2) of the second connecting line to the second throttle valve (204).

4. A charging device according to any one of the preceding claims, wherein: A first switching element (S1) is provided and is designed to enable or interrupt a current flow between the first input connection (L1) and the first connecting line (110).

5. The charging device according to any one of claims 2 to 4, wherein: A third switching element (S3) is provided and is designed to enable or interrupt a charging current between the third input connection (L3) and the third connecting line (130).

6. The charging device according to any one of claims 2 to 5, wherein: A seventh switching element (S7) is arranged between a center tap between the first and second diodes (D1, D2) and a center tap between the first and second capacitors (C1, C2).

7. A charging device according to any one of the preceding claims, in, In order to provide electrical energy at the bipolar AC voltage connection (400), the DC voltage provided at the positive intermediate connection (310) and at the negative intermediate connection (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), The fourth switching element (S4) establishes a connection from a center tap of the third half-bridge (230) via a third throttle valve (206) to the first AC voltage connection (410), and the sixth switching element (S6) establishes a connection from a center tap of the fourth half-bridge (240) to the second AC voltage connection (420).

8. The charging device according to any one of claims 2 to 7, in, In order to provide electrical energy at the intermediate joint (300), - either the AC voltage provided at the input connection unit (100) is provided at least partially as a DC voltage at the positive intermediate connection (310) and at the negative intermediate connection (320) via the PFC stage (200), The charging current is conducted to the intermediate terminal (300) via at least the first connecting wire (110) and the second connecting wire (120), or at least via the second part (120_2) of the second connecting wire, via the PFC stage (200), and preferably the entire charging current is conducted back via the neutral line (140). - either a DC voltage provided on the basis of a bidirectional DC voltage converter (550) connected to the intermediate terminal (300) and a battery (560) connected to the bidirectional DC voltage converter is provided at the positive intermediate terminal (310) and at the negative intermediate terminal (320), wherein for this purpose the bidirectional DC voltage converter converts the voltage of the traction battery into a DC voltage to be provided at the positive intermediate terminal (310) and at the negative intermediate terminal (320).

9. The charging device according to any one of claims 2 to 8, wherein: The charging device (500) is configured to provide an AC voltage at the first input terminal (L1) and the neutral terminal (N1) at the input terminal unit (100), In order to provide electrical energy at the first input connection (L1) and the neutral connection (N1), the DC voltage provided at the positive intermediate connection (310) and at the negative intermediate connection (320) is provided at least partially as an AC voltage at the first input connection (L1) and at the neutral connection (420), The current between the positive intermediate terminal (310) and the first input terminal (L1) is conducted via the first throttle valve (202), and the current between the negative intermediate terminal (320) and the neutral terminal (N1) is conducted via the second throttle valve (204).

10. A drive train (600) of a vehicle (700) having a charging device (500) according to any one of the preceding claims, wherein: The drive train (600) comprises, in particular, a traction battery (470), an inverter (472) and / or an electric machine (474).

11. A vehicle (700) having a drive train (600) according to claim 10.

12. A method (800) for operating a charging device according to any one of claims 1 to 9, the method comprising the step of controlling (810) the high-side and low-side switches of the fourth and sixth switching elements (S4) and (S6) and the third and fourth half bridges (210, 220, 230, 240) in order to provide electrical energy at the bipolar AC voltage connection (400).

13. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method (800) according to claim 12.

14. 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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