Charger and method for operating charger

Abstract

The invention relates to a charger for a vehicle, said charger (500) comprising, on the input side, an input connection unit (100) for connecting a multi-phase alternating voltage; and a PFC stage (200) for providing a DC voltage at an intermediate connection (300), in which a second connection line (120) is divided into a first part (1201) of the second connection line and a second part (1202) of the second connection line, in which a second switching element (S2) is provided for switching the first part (1201) of the second connection line and the second part (1202) of the second connection line. The second switching element is arranged between the first part (1201) of the second connection line and the second part (1202) of the second connection line and is configured to conduct a charging current from the second input connection (L2) to the second choke (204) via the first and second parts (1201, 1202) of the second connection line, or a charging current is conducted from the first connection line (110) to the second choke (204) via the second portion (1202) of the second connection line.

Description

Technical Field

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

[0002] A charger, for example in a vehicle with an electric drive in an electric vehicle or hybrid vehicle, is used to recharge a battery, preferably a storage battery or a traction battery, from an electrical energy source, preferably an external AC power source or a public AC power grid. To this end, the charger converts the sinusoidal AC power of the external energy source into DC power. In single-phase AC power, the power is pulsated at twice the AC frequency.

[0003] The charger preferably has two-stage power electronics. The first stage, the so-called Power-Factor-Correction stage, or PFC stage, converts the sinusoidal input voltage from the AC grid into a DC voltage. The second stage consists of a DC voltage converter or DC / DC converter, which ensures galvanic isolation by means of a transformer and adjusts the voltage level. Preferably, the output voltage and / or the output current for charging the battery are regulated with the aid of a circuit and a control system. An intermediate capacitor is arranged between the two stages, which buffers the power pulsations at twice the frequency of the AC power. Typically, the intermediate circuit is implemented by at least one electrolytic capacitor. These topologies make it possible to maintain a nearly sinusoidal input current on the grid side to meet grid-side standards; to achieve galvanic isolation between the grid and the vehicle to meet safety requirements; and to provide a constant output DC on the battery side in order to minimize the load on the battery during the charging operation.

[0004] In a vehicle with an electric drive, the battery is also connected to an inverter for providing energy to the electric drive motor. A DC voltage converter is connected in parallel with the inverter to power the vehicle's low-voltage grid or onboard grid, thereby supplying energy to the control device. At the beginning of the charging process, the charger is connected to a sinusoidal input voltage from an AC grid or an AC low-voltage grid via a PFC stage. On the output side, the PFC stage is connected or wired to an intermediate capacitor, which is part of the voltage intermediate circuit. The voltage intermediate circuit is discharged when connected to the AC low-voltage grid. Due to the low impedance of the voltage intermediate circuit, a high surge current is formed when the AC low-voltage grid is connected, which charges the voltage intermediate circuit. In order to avoid grid-side interference or damage to components of power electronic equipment, such as fuse tripping due to overcurrent, the surge current must be limited. A common way to limit the surge current is to limit it through pre-charging resistors in the connecting line between the AC grid and the PFC stage, which are bridged by relays during normal operation. The corresponding surge current must be limited in each connecting line of the PFC stage. This requires a large number of pre-charging resistors and relays. Therefore, a simple and compact solution is needed that can achieve the charging of the intermediate capacitor with fewer components. Summary of the invention

[0005] A charger for a vehicle is proposed.

[0006] The charger comprises, on the input side, a multi-phase, i.e., n-phase, preferably three-phase input terminal connection unit for connecting an n-phase AC voltage, wherein n is an integer greater than 1; and a PFC stage for providing a DC voltage at a bipolar intermediate connection terminal. The intermediate connection terminal comprises a positive intermediate connection terminal and a negative intermediate connection terminal. For each of the n phases, the PFC stage comprises an nth half bridge. The half bridges respectively comprise a series circuit having a high-voltage side switch and a low-voltage side switch. Each intermediate tap between the high-voltage side switch and the low-voltage side switch of the half bridge can be connected to one of the n input connection terminals of the n-phase input terminal connection unit through a choke, respectively, via the nth connection line. Thus, for example, the intermediate tap of the first half bridge can be connected to the first input connection terminal through the first choke via the first connection line. Thus, for example, the intermediate tap of the second half bridge can be connected to the second input connection terminal through the second choke via the second connection line, and so on. The n half bridges are connected in parallel, and their ends are connected to the bipolar intermediate connection terminal. The high-voltage side switch is connected to the positive intermediate connection of the bipolar intermediate connection, and the low-voltage side switch is connected to the negative intermediate connection of the bipolar intermediate connection. An intermediate capacitor is connected between the positive intermediate connection and the negative intermediate connection. The intermediate capacitor is part of the voltage intermediate circuit. The second connection line is divided into a first part of the second connection line and a second part of the second connection line. A second switching element is provided, which is arranged between the first part of the second connection line and the second part of the second connection line and is set up to conduct a charging current from the second input connection via the first part and the second part of the second connection line to the second choke, or to conduct a charging current from the first connection line via the second part of the second connection line to the second choke. The second switching element, preferably the second changeover contact, is arranged between the first part of the second connection line and the second part of the second connection line. Therefore, depending on the switch position of the second switching element, the charging current is conducted from the second input connection via the first part and the second part of the second connection line to the second choke, or the charging current is conducted from the first connection line via the second part of the second connection line to the second choke.

[0007] Advantageously, a circuit with a multiphase AC voltage input for a charger is provided, in which a surge current for charging an intermediate capacitor may not flow through all phases of the AC voltage input. Advantageously, by means of a second switching element, a first part of the second connection line can be decoupled from the PFC stage and thereby from the intermediate capacitor. Thus, preferably, the first part of the second connection line is connected to the PFC stage only after the intermediate capacitor has been charged. Thus, preferably, a surge current is prevented when the first part of the second connection line is connected. Advantageously, a pre-charging resistor, preferably a pre-charging resistor bridging the switching element, is omitted between the second input connection and the first part of the second connection line. Preferably, a short circuit between the first connection line and the first part of the second connection line is prevented due to the second switching element being designed as a second changeover contact. Preferably, by means of a simple switching element that is erroneously actuated, a short circuit between the first input connection and the second input connection can occur. By means of the second changeover contact, this error situation can be reliably excluded during actuation. Preferably, in addition to the first and second phases of the PFC stage, switching elements corresponding to the second switching elements and their arrangement are also embedded in further phases in order to also dispense with precharging resistors in these further phases.

[0008] Preferably, the external energy source is a multiphase, preferably three-phase AC grid, preferably a public low-voltage grid. Preferably, in North America or Japan, this is a single-phase AC grid with 120 or 240 volts. Preferably, in China or Europe, this is a three-phase AC grid with about 230 volts. For the charging operation of the charger, the charger is preferably connected to the corresponding AC grid via an n-phase input terminal connection unit, or to a corresponding AC voltage. Preferably, the n-phase input terminal connection unit comprises a neutral conductor connection terminal for connecting the neutral conductor of the AC grid to be connected. The battery to be charged is preferably a storage battery or a traction battery, with the help of whose energy the electric drive train of the vehicle is operated. The rectifier circuit is preferably a rectifier for converting AC power into DC power. The high-side switch or the low-voltage side switch of the semiconductor bridge is preferably a power semiconductor switch including an intrinsic diode, preferably an IGBT or a MOSFET, preferably based on Si, SiC or GaN technology. Preferably, the expression "connecting, for example, a center tap to a connecting line" means: connecting, contacting or connecting these components by means of a conductive line or a galvanic connection. The expression "blocking, preventing, decoupling or blocking the flow of current" means: disconnecting a conductive line or a connection. Preferably, the expression "switching" is used synonymously with "electrically connecting", wherein "connecting in a switchable manner" means: the electrical connection can be established or disconnected, preferably by means of a switch or a switching element. Preferably, the expression "arrangement" is used to define the position of an electrical component, preferably a switch or a switching element, within a circuit topology, wherein this includes electrical connections to adjacently arranged electrical components.

[0009] In one embodiment, in order to charge the intermediate capacitor before the charging process begins, the second switching element is controlled so that the charging current is conducted from the first connecting line via the second part of the second connecting line to the second inductor. Preferably, a current flow between the first part of the second connecting line and the second part of the second connecting line is thus prevented.

[0010] Advantageously, the second switching element is controlled to prevent a current flow via the first part of the second connecting line to the second part of the connecting line when the intermediate capacitor is charged, thereby preventing high surge currents from forming through the second phase of the input terminal connection unit for connecting a multiphase AC voltage.

[0011] In one embodiment, the intermediate capacitor is charged until the voltage at the intermediate capacitor corresponds to a predefinable voltage value or exceeds this voltage value.

[0012] The control of the second switching element for the charging process of the intermediate capacitor is carried out until the voltage at the intermediate capacitor corresponds to a predeterminable voltage value or exceeds this voltage value. For this purpose, the voltage at the intermediate capacitor is determined by means of a determination unit or a measuring device and compared with the predeterminable voltage value. The predeterminable voltage value is specified as a function of the voltage at the second input connection terminal or corresponds to this voltage. In order to determine the predeterminable value, the voltage at the second input connection terminal is preferably determined by means of a suitable determination unit or a measuring device and is preferably specified as a voltage value as a function of the value of the maximum amplitude. Alternatively, the voltage value is preferably specified as a function of the connected AC voltage or the region in which the charger is operated, or is preferably read out from a comprehensive characteristic curve and specified.

[0013] Alternatively, in another embodiment, the intermediate capacitor is charged until the alternating current through the first and / or second connecting line or through the first connecting line and / or at least the second part of the second connecting line is lower than a predeterminable alternating current value. Preferably, the predeterminable alternating current value is approximately 100 mA. Preferably, the predeterminable alternating current value is predetermined to be low, so that: when the second switching element is subsequently actuated so that the charging current is conducted from the second input connection via the second connecting line, via the first part of the second connecting line and via the second part of the second connecting line to the second choke, no overcurrent occurs. For this purpose, preferably, during the charging of the intermediate capacitor, the alternating current is determined by means of an alternating current measuring unit. For this purpose, the alternating current measuring unit is preferably arranged between the first input connection and the intermediate connection and / or between the second input connection and the intermediate connection.

[0014] Preferably, an actuation for a charger is provided which prevents high surge currents via the second phase of an input connection unit for connecting a multiphase AC voltage.

[0015] In another embodiment, in order to provide electrical energy at the intermediate connection terminal for the charging process, the AC voltage provided at the input terminal connection unit is at least partially provided as a DC voltage at the positive intermediate connection terminal and at the negative intermediate connection terminal via a PFC stage, wherein the second switching element is controlled so that the charging current is conducted to the intermediate connection terminal via at least the first connection line and the second connection line, or via at least the first connection line and at least the second part of the second connection line, and via the PFC stage.

[0016] During the charging process, the charger converts the electrical energy provided at the input terminal connection unit, the provided AC voltage or the provided AC current, into a charging voltage for charging a battery, preferably for charging a vehicle battery. For this purpose, the charger is constructed in two stages. With the help of the first stage, the PFC stage, the sinusoidal input voltage from the AC grid is converted into a DC voltage at the voltage intermediate circuit. With the help of the second stage, the downstream DC voltage converter, the voltage level is adjusted and the charging voltage and charging current for charging the battery are provided on the output side with the help of the circuit and the control system, and the DC voltage converter preferably ensures galvanic isolation by means of a transformer. Preferably, when a single-phase AC voltage is provided, the second switching element is controlled so that the charging current is conducted to the intermediate terminal via at least the first connecting line and at least the second part of the second connecting line and via the PFC stage. Here, preferably, the charging current is distributed to two phases within the PFC stage, and the load on the electronic components is thus relieved. Preferably, the charger can be operated with a higher charging current in single-phase operation than in multi-phase operation. Preferably, when a two-phase or multi-phase AC voltage is provided, the second switching element is controlled so that the charging current is conducted to the intermediate connection terminal via at least the first connecting line and the second connecting line, and via the PFC stage. Preferably, the charging current from the AC grid is conducted directly to the intermediate connection terminal via the PFC stage for each phase.

[0017] Advantageously, a topology is provided which, for a charging process, can provide a DC voltage at the intermediate terminal, wherein the energy for this is provided by an external energy source which provides a multiphase AC voltage at the input terminal unit.

[0018] 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 via the first switching element.

[0019] The first switching element is arranged between the first connection line and the first input connection. The first switching element is provided and is configured to enable or interrupt a current flow between the first input connection and the first connection line or the first choke of the PFC stage. Thus, depending on the switch position, a current flow or a charging current from the first input connection via the first switching element in the direction of the first choke of the PFC stage is enabled or prevented.

[0020] Advantageously, by means of the first switching element, a possibility is provided to interrupt or switch on a charging current through the first connection line by means of the first switching element. Preferably, the first switching element is connected in parallel with a pre-charging resistor, preferably a positive temperature coefficient resistor or a PTC resistor, which is used to limit an inrush current. Preferably, when charging the intermediate capacitor, the inrush current flows from the first input connection via the pre-charging resistor via the PFC stage into the intermediate capacitor. The pre-charging resistor reduces the inrush current and thereby prevents overcurrent. Preferably, in order to avoid losses in the pre-charging resistor, the pre-charging resistor is bridged by means of closing of the first switching element when the intermediate capacitor is substantially fully charged.

[0021] In another configuration, the intermediate capacitor is designed as a series circuit consisting of a first capacitor and a second capacitor.

[0022] The intermediate capacitor is preferably designed as a series circuit of a first capacitor and a second capacitor. Preferably, the capacitance of the first capacitor and the second capacitor is the same. Preferably, at the center tap between the first and second capacitors, a neutral conductor is connected, preferably in a switchable manner, for connection to a corresponding contact of the input connection unit. Preferably, a neutral conductor is provided for operation of the charger under asymmetrical loads. Preferably, an asymmetrical load is present when operating with a 2-phase grid or even when operating with a 3-phase grid (i.e., a two-phase or three-phase AC voltage). In these cases, the compensating current flows back into the AC grid connected on the input side via the neutral conductor.

[0023] Advantageously, a suitable circuit topology for connecting the neutral conductor is provided.

[0024] 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 inductor of the PFC stage.

[0025] The third switching element is arranged between the third connecting line and the third input connection. Thus, depending on the switch position, a current flow or a charging current in the direction of the third choke of the PFC stage from the third input connection is enabled or prevented. Advantageously, a possibility is provided to interrupt or switch on a charging current through the third connecting line, preferably through the third connecting line when a three-phase charging current is present. Preferably, the third switching element is connected in parallel with a pre-charging resistor, preferably a positive temperature coefficient resistor or a PTC resistor, which is used to limit the inrush current. Preferably, the inrush current flows from the third input connection via the PFC stage into the first and / or second capacitor. Preferably, in order to avoid losses in the pre-charging resistor, the pre-charging resistor is bridged by means of the closing of the third switching element when the first and / or second capacitor is substantially fully charged.

[0026] The invention also relates to a power train of a vehicle having a charger, as described above, wherein the power train comprises in particular a traction battery, an inverter and / or an electric machine. Advantageously, a power train of an electric vehicle having a charger with a simplified circuit topology is provided.

[0027] The invention also relates to a vehicle having a drive train as described above. Advantageously, a vehicle is provided having a charger with a simplified circuit topology.

[0028] The invention also relates to a method for operating a charger as described above, the method comprising the steps of controlling the second switching element, and preferably the first switching element, and the high-side and low-side switches of the half-bridges for providing electrical energy at a bipolar intermediate connection.

[0029] By means of actuating the second switching element and preferably the first switching element and the switches of the half-bridges, the AC voltage present at the input connection is first used to charge the intermediate capacitor and then permanently converted into a DC voltage for supplying the connected DC voltage converter of the charger in order to generate a charging voltage for the battery to be charged. Advantageously, a method is provided by means of which a DC voltage can be provided at the voltage intermediate circuit.

[0030] The invention also 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.

[0031] The invention also relates to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to perform the described method.

[0032] It will be appreciated that the features, characteristics and advantages of the charger can be applied or adapted to the method or the powertrain and the vehicle accordingly, and vice versa.

[0033] Further features and advantages of embodiments of the invention emerge from the following description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the following, the invention will be explained in more detail with reference to some drawings, for which:

[0035] Figure 1 A schematic diagram showing an embodiment of a circuit topology of a charger known from the prior art;

[0036] Figure 2 A schematic diagram showing an embodiment of a circuit topology of a charger;

[0037] Figure 3 A schematically presented vehicle having a powertrain with a charger is shown;

[0038] Figure 4 A schematically presented flow chart of a method for operating a charger is shown. DETAILED DESCRIPTION

[0039] Figure 1A charger 500 is shown, preferably a charger for a vehicle. The charger 500 comprises, on the input side, an input connection unit 100 for connecting the three-phase AC voltage shown as an example, and a PFC stage 200 for providing a DC voltage at an intermediate connection terminal 300. The PFC stage 200 of the charger 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-voltage side switch 211, 213, 215 and a low-voltage side switch 212, 214, 216. Each intermediate tap between the high-voltage side switch and the low-voltage side switch of the half bridge can be connected to the first, second and third input connection terminals L1, L2, L3 of the input connection unit 100 respectively via the first, second and third connection lines 110, 120, 130 respectively through the first, second and third chokes 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 choke 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 choke 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 choke 206 via the third connecting line 130. The half bridges 210, 220, 230 are connected in parallel. The ends of these half bridges are connected to the bipolar intermediate connection 300. The high-voltage side switch is connected to the positive intermediate connection 310, and the low-voltage side switch is connected to the negative intermediate connection 320. Preferably, a DC voltage converter 450 is connected to the intermediate connection 300. The DC voltage at the intermediate connection 300, attached to the input side of the DC voltage converter 450, 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 to the output side of the DC voltage converter 450. Preferably, a further DC voltage converter 460, preferably a buck converter, is connected in parallel with the battery 470 for converting the charging voltage into a low-voltage voltage for charging the low-voltage battery 462 and for supplying the vehicle's onboard power supply system and thus the vehicle's control devices. The low-voltage battery 462, and preferably further low-voltage electrical consumers 480, are connected to the vehicle's onboard power supply system. Preferably, the further DC voltage converter 460 is a bidirectional DC voltage converter. In this way, it is preferably possible to use the further DC voltage converter 460 to pre-charge the high-voltage intermediate circuit before the battery 470 is connected to the charger 500. The high-voltage intermediate circuit is attached to the output side of the DC voltage converter 450.

[0040] Based on Figure 1 Charger 500, according to Figure 2The charger 500 according to the present invention comprises an n-phase input terminal connection unit 100 for connecting a multiphase AC voltage having n phases, wherein n is greater than 1. By way of example, a three-phase input terminal connection unit for connecting a three-phase AC voltage is shown. The second connection line 120 is divided into a first part 120_1 of the second connection line and a second part 120_2 of the second connection line. For this purpose, a second switching element S2 is provided, which is arranged between the first part 120_1 of the second connection line and the second part 120_2 of the second connection line. The second switching element S2 is set up to conduct the charging current from the second input connection terminal L2 via the first and second parts 120_1, 120_2 of the second connection line to the second choke 204, or to conduct the charging current from the first connection line 110 via the second part 120_2 of the second connection line to the second choke 204. In order to realize this function, the second switching element S2 is preferably designed as a changeover contact. Preferably, a first switching element S1 is provided and is set up to enable or interrupt the current flow between the first input connection L1 and the first connection line 110. Preferably, a third switching element S3 is provided and is set up to enable or interrupt the charging current between the third input connection L3 and the third connection line 130. Preferably, the first switching element S1 and the third switching element S3 are connected in parallel with a pre-charging resistor, preferably a switchable resistor, a positive temperature coefficient resistor or a PTC resistor, in order to limit the inrush current when the AC voltage is connected to the input connection unit 100 before the first and third switching elements S1, S3 are closed. An intermediate capacitor CZ is connected in parallel with these half bridges 210, 220, 230. Preferably, the intermediate capacitor CZ is replaced by a series circuit (not shown) consisting of a first capacitor C1 and a second capacitor C2. Preferably, a current sensor is arranged in series with the first, second and third chokes 202, 204, 206 (not shown), respectively, for determining the current flowing through the respective chokes 202, 204, 206. Preferably, the high-side switch and the low-side switch and the switching elements are manipulated according to the determined current to achieve the desired operating mode. Preferably, a voltage sensor (V) is arranged between the positive intermediate connection terminal and the negative intermediate connection terminal 310, 320 for determining or measuring the voltage at the intermediate capacitor. Preferably, the high-side switch and the low-side switch and the switching elements are manipulated according to the determined voltage to achieve the desired operating mode. Preferably, the negative intermediate connection terminal 320 is connected to the ground GND. Preferably, GND is an internal voltage potential. Preferably, the voltage at the intermediate capacitor between the positive intermediate connection terminal 310 and the negative intermediate connection terminal 320 is measured or determined. Preferably, the voltage at the second input connection terminal is measured and determined relative to the neutral conductor connection terminal (not shown).Preferably, these switching elements are provided as semiconductor switching devices (IGBTs or MOSFETs, based on Si, SiC or GaN) or as contactors or relays.

[0041] Figure 3 A schematically presented vehicle 700 is shown, which has a drive train 600 with a charger 500. The vehicle 700 is shown here only by way of example with four wheels, wherein the invention can likewise 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 one charger 500. Furthermore, the drive train preferably comprises a battery 470, an inverter 472 and / or an electric motor 474.

[0042] Figure 4 A schematically presented flow chart of a method 800 for operating the charger 500 is shown. The method 800 starts at step 805. In step 810, the second switching element S2, preferably the first switching element S1, and the high-side and low-side switches of the half-bridges 210, 220, 230 are controlled for providing electrical energy at the intermediate capacitor CZ. The method ends with step 815.

Claims

1. A charger for a vehicle, in, The charger (500) comprises, on the input side: an input terminal connection unit (100) for connecting a multi-phase AC voltage, the multi-phase AC voltage having n phases, wherein n is greater than 1; and a PFC stage (200) for providing a DC voltage at an intermediate connection terminal (300). wherein the PFC stage (200) comprises a half bridge (210, 220, 230) for each of the n phases, The half bridges (210, 220, 230) respectively comprise a series circuit having a high-voltage side switch (211, 213, 215) and a low-voltage side switch (212, 214, 216), wherein each intermediate tap between the high-voltage side switch and the low-voltage side switch of the half bridge can be connected to one of the n input connection terminals (L1, L2, L3) of the input terminal connection unit (100) through a choke coil (202, 204, 206) via an nth connection line (110, 120, 130), respectively. wherein n half bridges (210, 220, 230) are connected in parallel, and the ends of the half bridges are connected to a bipolar intermediate connection terminal (300), wherein the high voltage side switch is connected to a positive intermediate connection terminal (310), and the low voltage side switch is connected to a negative intermediate connection terminal (320), wherein an intermediate capacitor (CZ) is connected between the positive intermediate connection terminal (310) and the negative intermediate connection terminal (320), It is characterized in that 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, 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, and is configured to conduct a charging current from the second input connecting terminal (L2) via the first part and the second part (120_1, 120_2) of the second connecting line to the second choke (204), or to conduct a charging current from the first connecting line (110) via the second part (120_2) of the second connecting line to the second choke (204).

2. The charger according to claim 1, in, In order to charge the intermediate capacitor (CZ) before the start of a charging process, the second switching element (S2) is actuated such that a charging current is conducted from the first connecting line (110) via the second section (120_2) of the second connecting line to the second inductor (204).

3. The charger according to claim 2, in, The intermediate capacitor (CZ) is charged until the voltage at the intermediate capacitor (CZ) exceeds a predeterminable voltage value.

4. A charger according to any one of the preceding claims, in, In order to provide electrical energy at the intermediate connection terminal (300) for a charging process, the AC voltage provided at the input terminal connection unit (100) is provided at least partially via the PFC stage (200) as a DC voltage at the positive intermediate connection terminal (310) and at the negative intermediate connection terminal (320), The second switching element (S2) is controlled so that the charging current is conducted to the intermediate connection terminal (300) via at least the first connection line (110) and the second connection line (120), or via at least the first connection line (110) and at least the second part (120_2) of the second connection line, and via the PFC stage (200).

5. A charger 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) via the first switching element (S1).

6. A charger according to any one of the preceding claims, wherein: The intermediate capacitor (CZ) is designed as a series circuit consisting of a first capacitor (C1) and a second capacitor (C2).

7. A powertrain (600) of a vehicle (700), the powertrain having a charger (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).

8. A vehicle (700) having a powertrain (600) according to claim 7.

9. A method (800) for operating a charger according to any one of claims 1 to 6, The method comprises the following steps: The second switching element (S2) and the high-side and low-side switches of the half-bridge (210, 220, 230) are controlled (810) to provide electrical energy at the intermediate capacitor (CZ).

10. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method (800) according to claim 9.

11. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to perform the method (800) of claim 9.

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