Charging Station, Electric Vehicle and System Comprising a Charging Station and an Electric Vehicle

Abstract

Charging station for electric vehicles with an induction coil arranged for inductive coupling with an induction coil of an electric vehicle, a grid connection point arranged for connection to an electrical grid, a meter arranged to obtain an electrical power flow from the induction coil to the grid connection point, and a processor. In order that an inductive feedback from an energy storage of an electric vehicle can take place in a grid compatible manner, it is provided that the processor generates at least one synchronization signal for the electric vehicle coupled to the induction coil for synchronization of the input voltage at the induction coil with a grid frequency at the grid connection point. Also provided are an electric vehicle and a corresponding system.

Claims

1. A charging station for electric vehicles, comprising: an induction coil arranged for inductive coupling with an induction coil of an electric vehicle; a grid connection point arranged for connection to an electrical grid; a meter arranged to obtain an electrical power flow from the induction coil to the grids connection point; and a processor; wherein the processor generates at least one synchronization signal for the electric vehicle coupled to the induction coil for synchronization of the input voltage at the induction coil with a grid frequency at the grid connection point, the processor determining the mains frequency and zero crossings in order to generate the synchronization signal.

2. The charging station according to claim 1, wherein the processor is arranged to compare a measured value of the meter with a measured value received from the electric vehicle, in particular for obtaining an electrical power loss between the energy store and the meter and/or for detecting an electromagnetic coupling between a coil of the electric vehicle and the induction coil.

3. The charging station according to claim 1, wherein an AC/AC converter is arranged to convert the voltage tapped at the induction coil into a voltage of the grid connection point and/or wherein the AC/AC converter is arranged to convert the frequency present at the induction coil into a frequency of the grid connection point.

4. The charging station according to claim 1, wherein the number of windings of the induction coil is such that a voltage transformed from the output voltage of the electric vehicle can be tapped off at the induction coil.

5. The charging station according to claim 1, wherein in addition to the induction coil, a second coil with a different winding number than the induction coil is provided, and wherein the induction coil is arranged to receive electrical power from the electric vehicle, and wherein the second coil is arranged to output electrical power to the electric vehicle.

6. The charging station according to claim 1, wherein the induction coil and the second coil are encapsulated in a common housing and are connected to the meter via a supply line.

7. An electric vehicle, comprising: an energy storage; an induction coil arranged for inductive coupling with an induction coil of a charging station; a meter arranged to meter an electrical power flow from the energy storage device to the induction coil; a converter arranged between the energy store and the induction coil that generates an output voltage as a function of a synchronization signal received from a charging station, wherein the synchronization signal is determined based on the mains frequency and zero crossings.

8. The electric vehicle according to claim 7, wherein the meter is arranged between the inverter and the induction coil.

9. The electric vehicle according to claim 7, wherein the inverter comprises a DC/AC converter.

10. The electric vehicle according to claim 1, wherein the converter is set up both for converting an AC input voltage from the induction coil into a DC voltage for the energy store and for converting a DC voltage from the energy store into an AC output voltage for the induction coil, in particular in such a way that the AC input voltage is lower than the AC output voltage.

11. A system comprising: the charging station according to claim 1; and an electric vehicle, comprising: an energy storage; an induction coil arranged for inductive coupling with an induction coil of a charging station; a meter arranged to meter an electrical power flow from the energy storage device to the induction coil; a converter arranged between the energy store and the induction coil that generates an output voltage as a function of a synchronization signal received from a charging station, wherein the synchronization signal is determined based on the mains frequency and zero crossings.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0029] In the following, the subject-matter is explained in more detail with reference to a drawing showing embodiments. The drawings show:

[0030] FIG. 1 shows a charging station, according to the subject-matter;

[0031] FIG. 2 shows an electric vehicle, according to the subject-matter.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a charging station 2 with a grid connection point 4 for a grid 6. A three-phase grid 6 is shown, but any other configuration is also useful. In the following, three phases are not always shown or required, so that the following description can be valid for each individual phase of a multi-phase energy supply network.

[0033] The charging station 2 has a disconnection device 8 at the grid connection point 4, for example in the form of a contactor, at each individual phase. Such a load break switch makes it possible to disconnect charging station 2 from the electrical power supply network 6 even under load. Starting from the disconnection device 8, a meter 10 is arranged in the charging station 2. The meter 10 meters in particular the voltage, the current and/or the phase angle, preferably on each individual phase. In addition, the meter 10 can meter a frequency of the grid 6.

[0034] Via charging electronics 12, in which a processor can be arranged, the meter 10 can, for example, be connected to a stationary charging point 14. This charging point 14 makes it possible, for example, to charge an electric vehicle via an electric line. This charging point 14 is optional.

[0035] A converter 16 can be arranged in the area of the charging electronics 12. The converter 16 is preferably an AC/AC converter, designed to convert an input voltage into an output voltage and preferably to set the frequency. Finally, the charging electronics 12 and the meter 10 are connected to a communication device 18.

[0036] Starting from converter 16, a first induction coil 20 can be provided. The induction coil 20 is arranged to be coupled with an induction coil of an electric vehicle shown below. On the one hand, the induction coil 20 can be used exclusively for feeding electrical energy back into the grid 6, but on the other hand it is also conceivable that the induction coil 20 is also arranged for feeding the electric vehicle from the energy supply network 6.

[0037] In the first case, when the induction coil 20 is used exclusively for feedback purposes, a further coil 22 can be provided, which can also be connected to the grid 6 via converter 16. Coil 22 can, for example, be used to supply an energy storage of an electric vehicle shown below. Induction coil 20 and coil 22 can be encapsulated in a common housing 24.

[0038] FIG. 2 shows an electric vehicle 30 whose power-train is at least partly powered by an energy storage 32. The energy storage 32 is connected to a meter 36 via a converter 34. The meter 36 preferably measures current, voltage as well as frequency and/or phase position between current and voltage. The meter 36 is connected to a coil 38. In addition, meter 36 and converters 34 are connected to a communication device 40.

[0039] The charging station 2 works with the electric vehicle 30 in the case of a feedback electrical energy from the energy storage 32 into the grid 6 as follows.

[0040] First, the electric vehicle 30 is moved into the vicinity of charging station 2 in such a way that an inductive coupling between coil 38 and induction coil 20 should be ensured. Subsequently, an activation signal is used to first activate converter 34 for DC/AC conversion of the DC voltage from the energy storage 32 into AC voltage. This alternating voltage flows via the meter 36 to the coil 38 and induces a magnetic field there.

[0041] This magnetic field should induce an output voltage in the charging station 2 in the induction coil 20. This is detected via the meter 10. The meter 10 and 36 exchange their respective measured values via the communication devices 18 and 40. Preferably in the charging electronics 12, the measured values of the two meters 10 and 36 are evaluated. If a power flow is reported by meter 36 and meter 10 determines that a received power flow is below a lower limit value or above a certain amount of the power flow in counter 36, it can be concluded that coil 38 is not sufficiently inductively coupled to coil 20. In this case, a cut-off signal is transmitted to the communication device 40 via the communication device 18 and the feed-back is interrupted on the vehicle side.

[0042] Otherwise, if the measured values of the meters 36 and 10 are equal such that their difference falls below a lower limit value, it can be concluded that there is sufficient inductive coupling between coil 38 and induction coil 20. In this case, the measured value of meter 10 is subtracted from the measured value of meter 36, resulting in the power loss over the distance between meter 36 and meter 10. Thus it can be determined which energy from the energy storage 32 was actually received in the meter 10 and was therefore fed into the grid 6.

[0043] Before the start of a feedback process, the frequency of the phases at the electrical power supply network 6 can be determined in the meter 10. A corresponding synchronization signal is transmitted from the meter 10 via the charging electronics 12 to the communication device 18 and from there to the communication device 40.

[0044] The communication device 40 then controls the converter 34 in such a way that the DC/AC conversion of the converter 34 is synchronous with the grid frequency. In this case, the AC voltage tapable at the induction coil 20 is synchronous with the grid frequency and no longer has to be converted regarding frequency via the converter 16. The converter 16 can be used to change the voltage level in order to feed electrical power into the power supply network 6. In particular, the converter 16 can be used to raise a voltage level so that feedback into the grid 6 is possible. For this purpose, the voltage can be increased above the mains voltage of the grid 6, for example by an amount of more than 1%, but preferably less than 5%.

[0045] In order to correctly adjust the output voltage on the induction coil 20, it is also proposed that the winding ratio between the winding of the induction coil 20 and the winding of coil 38 is set such that transformation takes place. The voltage at the energy storage 32 and therefore the alternating voltage at the output of the converter 34 can be 400 V AC, for example. The output voltage at the induction coil 20 should be 370 V, for example. In this case, the winding ratio between coil 38 and induction coil 20 is 4:3.7. This causes the voltage at meter 36 to be transformed down to a lower voltage at meter 10.

[0046] Coil 22 can be used for feeding electrical energy from the grid 6 into the electric vehicle 30. Coil 22 is supplied with AC voltage via converter 16 and an AC voltage induced from the generated magnetic field can be tapped in coil 38 or a separate coil not shown. Here, too, a transformation can take place in such a way that an input-side voltage of 360 VAC, for example, is converted into an output-side voltage of 400 V AC at the meter 36. Then only one AC/DC conversion is necessary in the converter 34.

[0047] With the help of the system shown, it is particularly easy to ensure a grid-compatible feedback of electrical energy from an energy storage in an electric vehicle 30 to an energy supply grid.

[0048] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0049] The use of the terms a and an and the and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms comprising, having, including, and containing are to be construed as open-ended terms (i.e., meaning including, but not limited to,) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., such as) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0050] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.