OFF GRID WIND TURBINE ELECTRIC VEHICLE CHARGING SYSTEM AND METHOD

Abstract

An off grid electric system for charging electric vehicles. An electric storage system (BTS) is arranged to store electric power generated by a plurality of wind turbines. A plurality of electric vehicle charging stations are connected to the plurality of wind turbines, and the electric storage system by means of an off grid electric power network (CN), so as to allow each charging station to charge at least one electric vehicle (EV).

Claims

1. An off grid electric system for charging electric vehicles (EV), the system comprising: a plurality of wind turbines arranged to generate respective electric power outputs; an electric storage system arranged to store electric power generated by the plurality of wind turbines; a plurality of electric vehicle charging stations each capable of charging at least one electric vehicle (EV); and an off grid electric power network (CN) serving to connect the electric power outputs of the plurality of wind turbines, the electric storage system (BTS), and the plurality of electric vehicle charging stations, so at to generate electric power to the plurality of electric vehicle charging stations to allow charging of electric vehicles (EV).

2. The off grid electric system according to claim 1, wherein at least one of the plurality of wind turbines comprises an electric generator arranged to generate a Medium Voltage AC output.

3. The off grid electric system according to claim 2, further comprising an AC-DC converter connected to said Medium Voltage AC output to generate a DC electric power output.

4. The off grid electric system according to claim 3, wherein said output of said AC-DC converter is connected to a series connection of inputs of a plurality of separate DC-DC converters, wherein outputs of said separate DC-DC converters are connected to respective electric vehicle charging stations.

5. The off grid electric system according to claim 4, further comprising a re-chargeable battery system (BTS) comprising a battery converter, wherein the battery converter is connected to said output of said AC-DC converter.

6. The off grid electric system according to claim 3, further comprising a monolithic DC-DC converter connected to an output of said AC-DC converter, wherein the monolithic DC-DC converter has multiple sets of DC output terminals for separate charging of a plurality of electric vehicles.

7. The off grid electric system according to claim 6, wherein an input of the monolithic DC-DC converter is connected to a re-chargeable battery system (BTS).

8. The off grid electric system according to claim 3, further comprising a DC-DC converter connected to an output of said AC-DC converter, wherein a primary side of the DC-DC converter is monolithic, wherein a secondary side of the DC-DC converter is modular and has multiple sets of DC output terminals for separate charging of a plurality of electric vehicles.

9. The off grid electric system according to claim 8, wherein the DC-DC converter comprises a transformer, and wherein a re-chargeable battery system (BTS) is connected to a primary side of said transformer.

10. The off grid electric system according to claim 2, wherein said Medium Voltage AC output is connected to a plurality of modules, wherein each of the modules comprises: a modular converter arrangement comprising an AC-DC converter connected to said Medium Voltage AC output; a DC-DC converter arranged to provide a DC output for charging an electric vehicle in response to said AC-DC converter output; and a re-chargeable battery system (BTS) comprising a battery converter system connected to said DC-DC converter, and wherein said DC-DC converter shares one transformer with the battery converter system.

11. The off grid electric system according to claim 10, wherein said Medium Voltage AC output is connected to a plurality of sets of modules, wherein each set of modules comprises a series connection of a plurality of modules.

12. The off grid electric system according to claim 1, further comprising a control system (CS) arranged to control distribution of electric energy to the plurality of vehicle charging stations according to a control algorithm, wherein the control system is arranged to receive information indicative of a weather forecast (WF), and to apply said information to the control algorithm.

13. The off grid electric system according to claim 12, wherein the control algorithm is arranged to predict an available electric energy available from the plurality of wind turbines in response to the information indicative of the weather forecast, and to control distribution of electric energy to the plurality of vehicle charging stations and to or from the electric storage system accordingly.

14. The off grid electric system according to claim 12, wherein the control algorithm is arranged to predict an available electric energy available from the plurality of wind turbines, and to generate a plan for charging of electric vehicles accordingly.

15. A method for off grid charging an electric vehicle, the method comprising: generating Medium Voltage AC electric power outputs by a plurality of wind turbines; providing an electric storage system arranged to store electric power generated by the plurality of wind turbines; providing an off grid electric power network comprising an AC-DC converter; connecting the electric power outputs from the plurality of wind turbines, and the electric storage system to a plurality of electric vehicle charging stations by means of said off grid electric power network; and charging the electric vehicle by electric connection to one of the plurality of electric vehicle charging stations.

16. The method of claim 15, wherein at least one of the plurality of wind turbines comprises an electric generator arranged to generate a Medium Voltage AC output.

17. The method of claim 16, further comprising an AC-DC converter connected to said Medium Voltage AC output to generate a DC electric power output.

18. The method of claim 17, wherein said output of said AC-DC converter is connected to a series connection of inputs of a plurality of separate DC-DC converters, wherein outputs of said separate DC-DC converters are connected to respective electric vehicle charging stations.

19. The method of claim 18, further comprising a re-chargeable battery system (BTS) comprising a battery converter, wherein the battery converter is connected to said output of said AC-DC converter.

20. The method of claim 17, further comprising a monolithic DC-DC converter connected to an output of said AC-DC converter, wherein the monolithic DC-DC converter has multiple sets of DC output terminals for separate charging of a plurality of electric vehicles.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0045] The invention will now be described in more detail with regard to the accompanying figures of which

[0046] FIG. 1 illustrates a wind turbine,

[0047] FIG. 2 illustrates a block diagram of one embodiment,

[0048] FIGS. 3-6 illustrate electric diagrams of various embodiments,

[0049] FIGS. 7-10 illustrate configurations of various embodiments, and

[0050] FIG. 11 illustrates steps of a method embodiment,

[0051] The figures illustrate specific ways of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

DETAILED DESCRIPTION OF THE INVENTION

[0052] FIG. 1 illustrates a wind turbine system embodiment. The wind turbine has typically two or three rotor blades BL for driving an electric generator located inside the nacelle NC on top of a tower TW, Wind turbines may generate an electric power of at least 1 MW, such as 2-10 MW, or more.

[0053] In the context of the present invention, a preferred wind turbine has a permanent magnet electric generator that can generate an AC voltage of 2-10 kV, such as 4-8 kV, A power converter system with a filter and an AC-DC converter is preferably down-tower, e.g. in an enclosure inside the tower TW or in a separate enclosure outside the tower TW, such as a kiosk, e.g. at a distance of 5-50 m from the tower TW, The AC-DC converter may be a two-level, a three-level or a modular multi-level converter (MMC). For the present invention, it may be preferred that each wind turbine has a power capacity of such as 3-8 MW.

[0054] FIG. 2 shows a block diagram of a basic off grid electric system embodiment of the invention. A plurality of wind turbines WT1, WT2, WT3, WT4 generate respective electric power outputs to an off grid electric power network CN. This off grid electric power network CN serves to connect the outputs of the wind turbines WT1, WT2, WT3, WT4, a battery system BTS with re-chargeable battery cells, and a plurality of EV charging stations VC1, VC2, VC3, VC4 each capable of charging at least one EV. Hereby, the wind turbines WT1, WT2, WT3, WT4 can generate power to the rechargeable battery system BTS as well as the vehicle charging stations VC1, VC2, VC3, VC4. Further, in periods with low wind speeds, electric power from the battery system BTS can be applied to the vehicle charging stations VC1, VC2, VC3, VC4.

[0055] A control system CS having a processor system arranged to executed a control algorithm serves to control the off grid electric power network CN. The control system CS receives information indicative of a weather forecast WF, thereby allowing estimation of electric energy available from the wind turbines WT1, WT2, WT3, WT4 and the battery system BTS to charge a fleet of EVs for a period of time. With further input, e.g. online, regarding updated charge state and location of all single EVs of an EV fleet, the control system CS may be programmed to automatically generate a plan or schedule for charging of each single EV of the fleet. The EVs may be automatically called towards a specific one of the vehicle charging stations VC1, VC2, VC3, VC4 to a specific time, so as to avoid waiting time for charging. Further, in periods with high electric energy capacity, a rapid charging may be offered, while a slower charging time may be offered in periods with less electric energy available.

[0056] In the following, four different technical configurations of the off grid electric power connection network CN will be described for one single wind turbine, as examples, FIGS. 3-6 show four electric diagrams of different embodiments, all four embodiments have in common that the wind turbine has an electric generator G arranged to generate a MVAC output, e.g. an 4-8 kV AC, and an AC-DC converter connected to the MVAC output via a filter F to generate a DC electric power output. Further, one or more re-chargeable batteries B or re-chargeable battery systems BTS are included in all four embodiments. In all four embodiments, the wind turbine itself can be rather simple, e.g. without the need for a converter installed inside the nacelle, which facilitates installation and maintenance. FIGS. 7-10 show examples of physical layouts of the components of the four embodiments.

[0057] FIG. 3 shows a first off grid electric system embodiment the output of the AC-DC converter is connected to a series connection of inputs of a plurality of separate DC-DC converters, wherein outputs of said separate DC-DC converters are connected to respective EV charging stations VC. Further, a re-chargeable battery system BTS comprising a battery converter, wherein the battery converter is connected to said output of said AC-DC converter. Thus, this embodiment has separate DC-DC converters for each charging stations VC is provided, and the battery system BTS can be located separate from the wind turbine and also separate from the AC-DC converter. Each of the DC-DC converters may especially be dual active bridge type converters or resonant type converters. It may be preferred that the AC-DC converter is placed down-tower, e.g. in a first kiosk in the vicinity of the wind turbine, while a second kiosk may house the battery system BTS. The charging stations VC may be located 25-500 m further away from the first kiosk.

[0058] FIG. 4 shows a second off grid electric system embodiment with a monolithic DC-DC converter connected to the output of the AC-DC converter. The monolithic DC-DC converter has multiple sets of DC output terminals (i.e. multiple sets of + and − terminals) for separate charging of a plurality of EVs, thus providing separate charging stations VC. An input of the monolithic DC-DC converter is connected to a re-chargeable battery system BTS. Also in this embodiment, the AC-DC converter is preferably placed down-tower, e.g. in a kiosk in the vicinity of the wind turbine. At a distance of 25-500 m further away from the kiosk, the monolithic converter can be placed in a second kiosk. The battery system BTS may be placed also in the second kiosk or in a separate enclosure or kiosk.

[0059] FIG. 5 shows a third off grid electric system embodiment comprising a DC-DC converter connected to the output of the AC-DC converter, where the primary side of the DC-DC converter is monolithic, whereas the secondary side of the DC-DC converter is modular and has multiple sets of DC output terminals for separate charging of a plurality of EVs, thus providing the vehicle charging stations VC. The DC-DC converter comprises a transformer, and a re-chargeable battery system BTS is connected to the primary side of this transformer. Again, the AC-DC converter is preferably placed down-tower, e.g. in a kiosk in the vicinity of the wind turbine. At a distance of 25-500 m further away from the kiosk, the monolithic converter can be placed in a second kiosk. The battery system BTS may be placed also in the second kiosk or in a separate enclosure or kiosk.

[0060] FIG. 6 show a fourth off grid electric system embodiment where the MVAC output from the wind turbine generator G is connected to a plurality of modules VC each indicated by dashed lines. Each module has a modular converter arrangement comprising an AC-DC converter connected to the MVAC output of the generator G, a DC-DC converter arranged to provide a DC output for charging an EV in response to the AC-DC converter output, and a re-chargeable battery system B with a battery converter system connected to the DC-DC converter, and wherein the DC-DC converter shares one transformer with the battery converter system. As seen, the MVAC output is connected to a plurality of sets of modules VC, each set of modules comprising a series connection of a plurality of modules VC. Each module VC may have its own enclosure or kiosk.

[0061] FIG. 7 shows an example of physical configuration of the first embodiment, where a first kiosk CK with the AC-DC converter is placed in vicinity of the wind turbine WT, and further in a separate kiosk BTS the re-chargeable battery system is housed, also located in the vicinity of the wind turbine WT. At a distance of 25-500 m away from the first kiosk CK, separate enclosures are provided for the charging stations VC each capable of charging an EV.

[0062] FIG. 8 shows an example of physical configuration of the second or third embodiments. This is similar to the configuration in FIG. 7, except that the battery system BTS and the DC-DC converter system with charging station outputs VC are housing within one common enclosure, an enclosure placed 25-500 m away from the kiosk CK housing the AC-DC converter.

[0063] FIG. 9 shows an example of physical configuration of the fourth embodiment, where separate enclosures C K, e.g. kiosks, placed 25-500 m away from the wind turbine, each houses AC-DC converter, DC-DC converter as well as re-chargeable battery system. This setup is simple, since the enclosures with all elements contained therein can be mass produced and pre-manufactured for installation on site.

[0064] FIG. 10 shows another example of physical configuration, e.g. an implementation of the fourth embodiment, where a line of EV charging stations VC is placed within e.g. 500 m away from the wind turbine WT, thus allowing charging of a fleet of many EVs simultaneously.

[0065] FIG. 11 illustrates steps of an embodiment for a method off grid charging an EV. The method comprises generating G_MVAC MVAC electric power outputs by a plurality of wind turbines. Further, providing P BTS an electric storage system arranged to store electric power generated by the plurality of wind turbines, e.g. a high capacity Li-ion battery. Further, providing P_CN an off grid electric power network comprising an AC-DC converter, and connecting C_CN_VC the electric power outputs from the plurality of wind turbines, and the electric storage system to a plurality of EV charging stations by means of said off grid electric power network. Then, receiving R_WF a weather forecast with predicted wind speeds for the location of the wind turbines, thus allowing prediction of wind turbine power available, thereby allowing selection of a mix of electric power from the electric storage system and the wind turbines for charging of an EV. Finally, charging the EV by electric connection to one of the plurality of EV charging stations. Especially, such the method embodiment is advantageous for charging a fleet of EVs, where it is possible to automatically plan EV charging based on the predicted electric wind turbine power available versus time.

[0066] Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is to be interpreted in the light of the accompanying claim set. In the context of the claims, the terms “including” or “includes” do not exclude other possible elements or steps. Also, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.