Charging system for charging the traction battery of an electrically powered vehicle

Abstract

Charging system for charging the traction battery (1) of an electrically powered motor vehicle, comprising a first rectifier (3) which is galvanically connectable on its input side to an AC or three-phase power supply network (2) and which is connected on its output side via an intermediate circuit (4) provided for stabilizing the generated DC voltage to the input of a charging control circuit (5) which is connected on its output side to the traction battery (1), characterized in that the input of the first rectifier (3) can optionally also be connected to the output of a second rectifier (6) which is connected on its input side to a vehicle-side electrical winding (7) via which electrical energy from a charging station (8) connected to an AC or three-phase power supply network (2) is transferred to a charging system attachable to the motor vehicle.a coupling device comprising a stationary electrical winding (9) can be inductively transferred to the motor vehicle.

Description

[0001] The invention relates to a charging system for charging the traction battery of an electrically powered motor vehicle, comprising a first rectifier which can be galvanically connected on the input side to an AC or three-phase power supply network, and which is connected on the output side via an intermediate circuit provided for stabilizing the generated DC voltage to the input of a charging control circuit which is connected on the output side to the traction battery.

[0002] In such charging systems, the galvanic connection between the AC or three-phase power supply and the rectifier is usually established via connectors. To charge the vehicle's traction battery, a charging cable from a stationary charging station, equipped with a corresponding connector, is manually connected to a mating connector on the vehicle.

[0003] The present invention is based on the objective of designing a charging system for charging the traction battery of an electrically powered motor vehicle in such a way that it is as simple, universal and convenient to use as possible.

[0004] This problem is solved according to the invention by the fact that the input of the first rectifier can optionally also be connected to the output of a second rectifier, which is connected on the input side to a vehicle-side electrical winding, via which electrical energy from a charging station connected to an AC or three-phase supply network can be inductively transferred to the vehicle with a coupling device that can be attached to the vehicle and comprises a stationary electrical winding.

[0005] When the coupling device is attached to the vehicle, the stationary electrical winding of the charging station and the vehicle-side electrical winding together form a transformer, with the stationary electrical winding functioning as the primary winding and the vehicle-side electrical winding as the secondary winding of the transformer. The electrical windings can be designed, for example, as air-core coils and / or coils with a magnetic core, whereby the shape and cross-section of both the coils and any cores present can be adapted to the respective requirements regarding installation space, possible spacing between the coils, and the electrical power to be transmitted.

[0006] The components of the charging system according to the invention are preferably combined into a single device and enclosed in a common housing. For example, the first rectifier, the intermediate circuit, and the charging control circuit can be housed in a common housing, which is provided with a first plug connection for electrical contact with the AC or three-phase power supply network and with a second plug connection for electrical contact with the second rectifier.

[0007] Since high voltages can be supplied from different sides, it is advantageous to ensure safe handling by designing these two connectors in such a way that both the plug-side and socket-side connector parts are equipped with protective devices against unintentional contact.

[0008] With the charging system according to the invention, it is easily possible to provide the vehicle-side components for inductive energy transfer as a retrofit solution.

[0009] Further advantageous embodiments and developments of the charging system according to the invention are set out in the dependent claims and are explained with reference to the drawing.

[0010] The single figure, in a schematic representation, shows an embodiment of a charging system according to the invention. It depicts a charging station 8 in which both galvanic coupling of the vehicle-side charging system with an AC or three-phase power supply network 2 is provided, as well as galvanically isolated coupling by means of a stationary electrical winding 9. A significant advantage of the charging system according to the invention is that the mere presence of either of these options in a charging station 8 is sufficient to charge the traction battery 1. This makes the charging system considerably more flexible in its use.For example, in the home garage, only inductive transmission may be provided, which is convenient and can be used without cumbersome handling steps, while for recharging on the go, the connection via cable and connector can always be used, which will be more common at publicly accessible charging stations.

[0011] To prevent accidental parallel activation of both transmission paths at a charging station 8, thereby causing a short circuit, it is advantageous to provide a mechanism that, for example, automatically disconnects the electrical connection to the inductive transmission system when galvanic coupling with the AC or three-phase power supply network 2 is established. If the galvanic coupling of the vehicle-side charging system to the AC or three-phase power supply network 2 is achieved via a plug connection 10, as shown in the drawing, the plugging process can, for example, actuate a switch (not shown here) that interrupts the electrical connection to the second rectifier 6.

[0012] For inductive energy transfer to the vehicle, the charging station 8 includes a coupling device that can be attached to the vehicle and has a stationary electrical winding 9. The vehicle-side electrical winding 7, intended to cooperate with this stationary electrical winding 9, is located behind a license plate 12 of the vehicle. A contact surface of the coupling device of the charging station 8 can be attached to the outer surface of the license plate 12, so that the stationary electrical winding 9 of the charging station 8 (primary winding) and the vehicle-side electrical winding 7 (secondary winding) together form a transformer. To achieve a high efficiency of energy transfer using this transformer, the contact surface of the coupling device must be attached to the outer surface of the license plate 12 with the smallest possible distance between the primary and secondary windings.The transformer operates at a frequency on the order of approximately 100 kHz, and the second rectifier 6 is designed to convert the secondary-side voltage of this frequency into a DC voltage. Depending on the type of power supply network 2 on the primary side, and in particular whether it is an AC or three-phase power supply network 2, the DC voltage ranges between approximately 140 volts and 350 volts. This DC voltage is fed to the input side of the first rectifier 3, which is designed to convert an AC voltage of precisely this magnitude and with a frequency of 50 to 60 Hz into a corresponding DC voltage. The output DC voltage of the second rectifier 6, supplied to this first rectifier 3 on the AC side, passes through it—apart from minimal losses—virtually unimpeded.

[0013] The first rectifier 3 is connected on its output side to the intermediate circuit 4 of the charging system, which in turn is connected to the input of a charging control circuit 5. This circuit uses the supplied electrical energy to charge the traction battery 1 of the vehicle. On its input side, the first rectifier 3 can be connected either directly to the AC or three-phase power supply network 2 via connector 10, or via connector 11 to the output of the second rectifier 6, which is itself connected on its input side to the vehicle's electrical winding 7.

[0014] To charge the traction batteries 1, the driver of the electrically powered vehicle drives up to the charging station 8 and manually establishes the galvanic connection to the charging station 8 by coupling a connector part of a charging cable of the charging station 8 with a mating connector part present on the vehicle to form the plug connection 10.

[0015] Alternatively, if, for example, the charging station 8 in question does not provide a connection via a cable with a connector, the operator manually attaches the coupling device with the stationary electrical winding 9 to the outside of the official license plate 12, behind which the vehicle's electrical winding 7 is located. Depending on the design of the charging station 8, attaching the coupling device can also be fully automated without human intervention, whereby, for example, a camera-based positioning device detects the exact position of the license plate 12 and precisely positions the coupling device against the outer surface of the license plate 12.

Claims

[1] Charging system for charging the traction battery (1) of an electrically powered motor vehicle, comprising a first rectifier (3) which is galvanically connectable on the input side to an AC or three-phase power supply network (2) and which is connected on the output side via an intermediate circuit (4) provided for stabilizing the generated DC voltage to the input of a charging control circuit (5) which is connected on the output side to the traction battery (1), characterized by, that the input of the first rectifier (3) can optionally also be connected to the output of a second rectifier (6), which is connected on the input side to a vehicle-side electrical winding (7), via which electrical energy from a charging station (8) connected to an AC or three-phase supply network (2) can be inductively transferred to the vehicle with a coupling device that can be attached to the vehicle and comprises a stationary electrical winding (9). [2] Charging system according to claim 1, characterized by , that the stationary electrical winding (9) of the charging station (8) and the vehicle-side electrical winding (7) together form a transformer. [3] Charging system according to claim 1 or 2, characterized by , that the electrical windings (7, 9) are designed as air coils and / or as coils with a magnetic core. [4] Charging system according to any one of claims 1 to 3, characterized by, that the first rectifier (3) can be connected on the input side to the AC or three-phase power supply network (2) via a first plug connection (10) and to the second rectifier (6) via a second plug connection (11). [5] Charging system according to claim 4, characterized by , that the two connectors (10, 11) are designed such that both the plug-side and socket-side connector parts are provided with protective devices against unintentional contact. [6] Charging system according to any one of claims 1 to 5, characterized by , that the first rectifier (3), the intermediate circuit (4) and the charging control circuit (5) are housed in a common enclosure which is provided with a first plug connection (10) for electrical contact with the AC or three-phase power supply network (2) and with a second plug connection (11) for electrical contact with the second rectifier (6). [7] Charging system according to any one of claims 1 to 6, characterized by , that the vehicle-side electrical winding (7) is arranged behind a license plate (12) of the motor vehicle, and that a mounting surface of the coupling device of the charging station can be attached to the outer surface of the license plate.

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