Patent ID: 12246609

DETAILED DESCRIPTION

FIG.1shows a charging device100which, in operation, is electrically connected at an input-side first terminal110_1,110_2to an energy source200and at an output-side second terminal190_1,190_2to a battery300to be charged. The energy source200, the energy of which is intended to be used to charge the battery, is preferably a single-phase AC source, for example the public power supply grid. The charging device comprises a primary circuit400, on its input side, and an output-side secondary circuit500. The primary and secondary circuit are connected to one another, preferably inductively, via the primary winding150_1of a transformer150and the secondary coil150_2thereof, but are galvanically isolated. The primary circuit comprises a rectification circuit405and a parallel connection of two branches each having a high-side element, preferably an electrical component which is arranged on the high side of a half-bridge, and a low-side element, preferably an electrical component which is arranged on the low side of the half-bridge. A first branch comprises a first and a second series-connected capacitor422,424and a first center tap426between the capacitors. The first center tap426is connected to a first connection pole152of the primary winding150_1of the transformer. A second branch comprises a series-connected first low-side switching element S1and a second series-connected high-side switching element S2having a second center tap436between the switching elements S1, S2. The second center tap436is connected to a second connection pole154of the primary winding150_1. The intrinsic diodes of the first and of the second switching element S1, S2are aligned such that a flow from the low side to the high side of the second branch is made possible. The secondary circuit500comprises a parallel connection of two branches each having a high-side element and a low-side element. One of these branches, the third branch, comprises a series connection of a first high-side diode512and of a third low-side switching element S3having a third center tap516between the first diode and the third switching element. The third center tap516is connected to a second connection pole158of the secondary winding150_2of the transformer150. The first diode512and the intrinsic diode of the third switching element S3are aligned such that a flow from the low side to the high side of the third branch is made possible. A further branch of the secondary circuit, the fourth branch, comprises a series connection of a second high-side diode522and of a fourth low-side switching element S4having a fourth center tap526between the second diode522and the fourth switching element S4. The fourth center tap526is connected to a first connection pole156of the secondary winding150_2of the transformer150. The second diode522and the intrinsic diode of the fourth switching element S4are aligned such that a flow from the low side to the high side of the fourth branch is made possible. A first connection pole190_1of the second terminal190is connected to the cathodes of the first and second diode512,522and a second connection pole190_2of the second terminal190is connected to the third and fourth switching elements S3, S4at the ends of the third and fourth branch. The rectification circuit405according toFIG.1comprises a series-connected third high-side diode412and a fourth low-side diode414having a fifth center tap416between the third and fourth diode412,414. The fifth center tap is connected to a first connection pole110_1of the first terminal. The series-connected third high-side diode412and fourth low-side diode414are connected in parallel with the first and second capacitor422,424. The third and the fourth diode are aligned such that a flow from the low side to the high side is made possible. The first center tap426between the capacitors is connected to a second connection pole110_2of the first terminal. Preferably, a further, fifth branch is connected in parallel with the primary circuit400, which branch comprises a third capacitor425. Further, a fourth capacitor525is preferably connected between the fourth center tap526and the first connection pole156of the secondary winding of the transformer150.

FIG.2shows a schematic illustration of a second embodiment of a circuit topology for a charging device. The circuit topology and the reference signs largely correspond to the circuit topology shown inFIG.1. Only the differences from the circuit topology shown inFIG.1will be discussed below. The rectifier circuit405comprises a bridge rectifier having four diodes. This bridge rectifier is connected, on its input side, to a first connection pole110_1and to a second connection pole110_2of the first terminal, and, on its output side, is connected in parallel with the second capacitor424. Preferably, a further, sixth branch is connected in parallel with the secondary circuit500, which branch comprises a fifth capacitor536. In particular, in contrast to the topology according toFIG.1, for both grid half-cycles, there is a galvanic connection only to the second capacitor424.

FIG.3shows a schematic illustration of a third embodiment of a circuit topology for a charging device. The circuit topology and the reference signs largely correspond to the circuit topology shown inFIG.2. Only the differences from the circuit topology shown inFIG.2will be discussed below. The secondary circuit500of the charging device100comprises a parallel connection of two branches each having a high-side element and a low-side element. One of these branches, the third branch, comprises a series connection of a first high-side diode512and of a third low-side switching element S3having a third center tap516between the first diode and the third switching element. The third center tap516is connected to a second connection pole158of the secondary winding150_2of the transformer150. The first diode512and the intrinsic diode of the third switching element S3are aligned such that a flow from the low side to the high side of the third branch is made possible. A further branch of the secondary circuit, the fourth branch, comprises a series connection of a sixth capacitor532and of a seventh capacitor534having a fourth center tap526between the sixth and the seventh capacitor532,534. The fourth center tap526is connected to a first connection pole156of the secondary winding150_2of the transformer150. A first connection pole190_1of the second terminal190is connected to the cathode of the first diode512and a second connection pole190_2of the second terminal190is connected to the third switching element S3at the end of the third and fourth branch.

FIG.4shows a schematically illustrated vehicle600having a drive train650having a charging device100. The vehicle600is illustrated with four wheels here only by way of example, but the invention can equally be used in any vehicles with any number of wheels on land, on water and in the air. The drive train650illustrated by way of example comprises at least one charging device100. Further, the drive train preferably comprises a battery300, an inverter640and an electrical machine630.

FIG.5shows a schematically illustrated flow diagram for a method700for operating a charging device100. The method700starts with the step705. In step710, the second and the first switching element are alternately switched on and off. When the first switching element is switched on (720), the fourth switching element is switched on and switched off at least once. When the second switching element is switched on (730), the third switching element is switched on and switched off at least once. The method ends with step740.