Charging device for charging an electrical energy store

Abstract

The invention proposes a charging device for charging an energy store (4), comprising at least two charging contacts (1) for supplying electrical energy. This can be done by means of DC or AC voltage. The charging device also comprises a DC voltage path (DC+, DC-) and an AC voltage path (L1, L2 / N), wherein the AC voltage path (L1, L2 / and) leads to a charging controller (6). The charging controller (6) is then designed to convert an AC voltage into a DC voltage and to return this to the DC voltage path (DC+, DC-) via a return (7). The charging contacts (1) are designed to be able to be supplied with AC voltage and DC voltage and a switch (5) is integrated into the AC voltage path, this switch being able to interrupt the supply of electrical energy to the charging controller (6).

Description

[0001] Charging device for charging an electrical energy storage device

[0002] The present invention relates to a charging device for charging an electrical energy storage device, for example, in electrically powered vehicles. In this case, electrical energy is supplied to the vehicle via a charging cable via the corresponding charging device, thereby charging the vehicle's electrical energy storage device.

[0003] Various contact connections are known for transmitting electrical energy from the charging device to the vehicle. Conventionally, a charging cable with a charging plug is used, which has two wires for alternating current, five wires for three-phase current, or two wires for direct current. Combined charging cables are also known, which have wires for direct current and wires for alternating current and three-phase current.

[0004] On the vehicle side, corresponding inlets are used to connect the charging cable. An inlet is a charging socket that can connect the charging cable wires via appropriate contacts.

[0005] There are various standards for the arrangement of the contacts in the inlet, for example, the plug standard defined in IEC 62196. This standard specifies the different types of plugs used in different countries.

[0006] All known plug types according to IEC 62196 have in common that they offer different current paths for charging the electrical energy storage device using alternating current, three-phase current, or direct current. A corresponding charging cable, and thus also a corresponding inlet, has charging contacts for alternating current or three-phase current, as well as, if necessary, additional charging contacts for direct current.

[0007] In addition, other technologies for transmitting electrical energy to an energy storage device are known, such as the NACS (North American Charging Standard). Unlike the IEC 62196 standard, NACS uses charging contacts that can transmit both direct current and alternating current. Therefore, separate contacts are not used for alternating current and direct current.

[0008] For example, EP 3766727 A1 discloses a charger that uses charging contacts that can be supplied with either AC or DC voltage. A switching unit is disclosed, which is controlled by a controller and uses a DC voltage path or an AC voltage path to charge the electrical energy storage device, depending on the input voltage.

[0009] One problem that arises when using charging contacts with either AC or DC voltage is that in conventional vehicles designed for IEC 62196 contacting, charge controllers used to rectify AC to DC voltage can be affected by the application of DC voltage, as these are not normally designed for DC voltage. This can lead to the destruction of the charge controller, especially at higher DC voltages, such as those commonly used for charging vehicle energy storage devices.

[0010] The object of the present invention is therefore to provide a charging device which can use the same charging contacts for selectively charging an energy storage device with direct or alternating voltage, wherein the charging controller in the vehicle is to be protected from the application of a direct voltage.

[0011] This problem is solved with the features of the main claim.

[0012] For this purpose, a charging device is required for charging an electrical energy storage device. This energy storage device can be designed as a rechargeable battery or an accumulator.

[0013] The charging device contains at least two charging contacts for supplying electrical energy. These charging contacts are configured to accommodate a corresponding charging cable and can make electrically conductive contact with the corresponding wires in the charging cable.

[0014] The charging device also includes a DC voltage path and an AC voltage path. In this context, a voltage path refers to conduction paths that can conduct electrical energy. The DC voltage path can supply the energy storage device with electrical energy via the charging contacts.

[0015] The AC voltage path can also be designed for three-phase voltage. In this case, two of the charging contacts are also used for the electrical supply of DC voltage. Furthermore, the charging device includes a charge controller designed to convert an AC voltage into a DC voltage. This rectified voltage can then be used to charge the energy storage device via a feedback path to the DC voltage path. In a special embodiment, the charge controller can also be designed to transform a three-phase voltage into a DC voltage. The charge controller is preferably designed as an OBC (on-board charger).

[0016] To protect the charge controller, a switch is integrated into the AC voltage path. The AC voltage path leads from the charging contacts to the charge controller. The switch can then be activated when DC voltage is present at the charging contacts, preventing the DC voltage from reaching the charge controller.

[0017] The switch can be activated by a suitable voltage measurement or by an external pulse from a source, for example, on the vehicle. Instead of a voltage measurement, a frequency measurement is also conceivable. If a DC voltage is detected by the voltage measurement, the switch is triggered. This triggering can also be enabled if a frequency equal to zero is measured during a frequency measurement.

[0018] The switch is preferably designed as a solid-state switch. However, it can also be designed as a relay.

[0019] The DC voltage path also includes a DC isolation between the charging contacts and the rectified AC voltage return. This DC isolation prevents the rectified voltage after the charging controller and the supplied AC voltage from being present at the charging contacts at the same time.

[0020] If a DC voltage is applied to the charging contacts, the switch is triggered and de-energizes the charge controller. In this case, the DC isolation is not activated, and the DC voltage applied to the charging contacts is passed to the energy storage device via the DC voltage path.

[0021] For use in a vehicle, it is proposed to integrate the charging device into a vehicle inlet. Preferably, the charging device is installed in an inlet without the charging controller. This has the advantage that existing vehicles can be retrofitted with this charging device.

[0022] One embodiment of the charging device includes a separator for the energy storage device, which is arranged upstream of the energy storage device in the energy flow direction and thus, as seen from the charging contacts, downstream of the return line. This design enables a main circuit for the electrical energy to be charged. Such a main circuit is capable of interrupting the supply of electrical energy to the energy storage device to be charged, regardless of the frequency of the electrical voltage at the charging contacts. The energy flow direction is oriented from the charging contacts to the energy storage device.

[0023] For voltage measurement, a voltage measuring device is proposed that can measure the electrical voltage at the charging contacts. As already described, a frequency measuring device is also possible. Such a voltage or frequency measuring device is preferably also arranged in the inlet.

[0024] To evaluate the measured voltage or frequency and control the switch accordingly, an actuator is preferably provided. This actuator is electrically connected to the measuring device and can control the switch when a defined value is exceeded or undershot. The actuator can be implemented as a microcontroller or as a control element.

[0025] The switch must be designed to safely switch high currents, such as those commonly encountered in charging processes for electrical energy storage devices. Accordingly, the switch is preferably designed to switch currents up to 100A.

[0026] Likewise, the DC voltage path must be designed to safely switch high voltages, even under load. Accordingly, the DC voltage path, as well as the DC isolation and the isolation to the energy storage device, must be designed for an electrical DC voltage of over 400V.

[0027] The advantage of this invention over the prior art is that the electrical voltage at the charging contacts is not applied to the charge controller without restriction. This protects the charge controller from unsuitable electrical voltage. This is achieved by arranging the switch in the AC voltage path, i.e., in a voltage path that leads to the charge controller. This allows the electrical voltage to be switched before it reaches the charge controller.

[0028] In a preferred embodiment, the switch has a resting state, namely the open position. This means that, under normal conditions, no voltage reaches the charge controller via the AC voltage path.

[0029] If AC voltage is applied to the charging contacts, the DC disconnect is switched, interrupting the DC voltage path. The switch is also closed, allowing the AC voltage to be routed to the charge controller via the AC voltage path.

[0030] The charge controller then converts the AC voltage applied to the charge controller into a DC voltage, which is then fed back to the DC voltage path via the feedback loop. Since the DC voltage is fed back to the DC voltage path after the DC separation, the DC voltage thus converted can now be used to charge the energy storage device.

[0031] Further features can be seen in the attached drawing.

[0032] It shows:

[0033] Figure 1: A schematic representation of a charging device according to the invention.

[0034] Figure 1 shows a charging device according to the invention with two charging contacts 1. These charging contacts 1 can be supplied with direct current or alternating current. It is also conceivable to apply a three-phase voltage to the contacts, in which case at least three charging contacts should be provided, two of which can also be used to supply direct current.

[0035] The voltage applied to the charging contacts 1 is passed on via a DC voltage path DC+, DC- so that it can reach the energy storage device 4 to be charged. This DC voltage path can also include a DC disconnection 2 and / or a disconnection from the energy storage device 3. The DC disconnection 2 can interrupt the voltage at the charging contacts in the DC voltage path, and the disconnection of the energy storage device 3 can generally shut down the charging process and de-energize the energy storage device 4. The voltage at the charging contacts 1 is then passed to a charging controller 6 via an AC voltage path L1, L2 / N. Since the charging controller 6 is often not DC-proof, a switch 5 is integrated in the AC voltage path L1, L2 / N. The switch 5 can therefore interrupt the voltage flow from the charging contacts 1 to the charging controller 6 and thus de-energize the charging controller 6.

[0036] The AC voltage path L1, L2 / N can carry a single-phase or two-phase AC voltage to the charge controller 6. For single-phase voltages, the AC voltage path L1, L2 / N consists of the lines L1 and N; for two-phase AC voltages, it consists of the lines L1 and L2. Three-phase voltage supply lines consisting of three or more lines to the charge controller 6 are also conceivable.

[0037] When using multi-phase AC voltage paths L1, L2 / N, the switch must also be multi-phase to be able to switch all phases. For single-phase AC voltage paths L1, L2 / N, a single-phase switch is sufficient, as shown in Figure 1.

[0038] The switch 5 can be actuated via an actuator and thus enable or interrupt the supply of electrical voltage via the alternating voltage path L1, L2 / N to the charge controller 6.

[0039] The actuator, in turn, can be triggered by a corresponding voltage measurement (V) and / or a corresponding frequency measurement. For this purpose, a limit value can be defined in the actuator, which triggers when the limit is exceeded or undershot. The triggering causes switch 5 to switch.

[0040] The alternating voltage supplied to the charge controller 6 is rectified in the charge controller 6 and then fed back to the DC voltage path DC+, DC-. This return path 7, as well as the charge controller 6 itself and the AC voltage path L1, L2 / N, are arranged parallel to the DC separation 2, so that the returned DC voltage is fed to the DC voltage path in the direction of current flow after the DC separation 2 and can thus conduct an electrical DC voltage to the energy storage device 3 to be charged, independent of the DC separation 2.

[0041] The measuring devices V, f as well as the switch 5 and the isolation DC2 are preferably arranged in an inlet 8. The charge controller 6 can also optionally be arranged in the inlet 8. Otherwise, the charge controller is arranged, for example, in a vehicle. Likewise, the isolation to the energy storage device 3 and the energy storage device 4 itself are arranged, for example, in a vehicle. In this respect, the interaction of these components can also be viewed as a system. The present invention is not limited to the aforementioned features; rather, further embodiments are conceivable. For example, a further switch can be arranged in the feedback loop to achieve further safety. Likewise, the voltage measurement and / or the frequency measurement could be carried out on the vehicle side and reported to the actuator.

[0042] LIST OF REFERENCE SYMBOLS

[0043] 1 charging contacts

[0044] 2 DC separation 3 Energy storage separation

[0045] 4 energy storage

[0046] 5 switches

[0047] 6 charge controllers

[0048] 7 Return 8 Inlet

[0049] V Voltage measurement f Frequency measurement

[0050] DC+, DC- DC voltage path

[0051] L1 , L2 / N AC voltage path

Claims

CLAIMS 1 . Charging device for charging an energy storage device (4), with at least two charging contacts (1) for supplying electrical energy, with a DC voltage path (DC+, DC-) and an AC voltage path (L1, L2 / N), wherein the AC voltage path (L1, L2 / N) leads to a charging controller (6), wherein the charging controller (6) is designed to convert an AC voltage into a DC voltage and this is fed back to the DC voltage path (DC+, DC-) via a feedback (7), characterized in that the charging contacts (1) are designed to be able to be supplied with AC voltage and DC voltage and that a switch (5) is integrated into the AC voltage path, which switch can interrupt the supply of electrical energy to the charging controller (6).

2. Charging device according to claim 1, characterized in that a DC separation (2) is integrated in the DC voltage path (DC+, DC-) before the return (7).

3. Charging device according to claim 1 or 2, characterized in that the charging device is integrated in an inlet (8).

4. Charging device according to one of claims 1 to 3, characterized in that the charging contacts (1) can be supplied with an electrical voltage which has a frequency of 0 Hertz or higher.

5. Charging device according to one of claims 1 to 4, characterized in that a separation (3) is arranged in front of the energy storage device (4), which can interrupt the supply of electrical energy from the direct voltage path (DC+, DC-) and the return (7).

6. Charging device according to one of claims 1 to 5, characterized in that a voltage measuring device (V) is included which can measure the electrical voltage at the charging contacts (1).

7. Charging device according to one of claims 1 to 6, characterized in that a frequency measuring device (f) is included which can measure the frequency electrical voltage at the charging contacts (1).

8. Charging device according to claim 6 or 7, characterized in that an actuator is provided which actuates the switch (5) as a function of the voltage measurement (V) or the frequency measurement (f).

9. Charging device according to one of claims 1 to 8, characterized in that the energy storage device (4) is designed as a rechargeable battery in a vehicle.

10. Charging device according to one of claims 3 to 9, characterized in that the inlet (8) is integrated in a vehicle. 11 . Charging device according to one of claims 1 to 10, characterized in that the switch (5) is designed to be able to switch electrical currents up to 100 A.

12. Charging device according to one of claims 1 to 11, characterized in that the switch (5) is designed as an electronic solid-state switch.

13. Charging device according to one of claims 1 to 12, characterized in that the DC voltage path is designed for electrical DC voltages of more than 400V.

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