DC voltage charging post for charging an electric vehicle

Abstract

The invention describes a DC voltage charging post (100; 200; 300) for charging an electric vehicle. The DC voltage charging post (100; 200; 300) comprises two DC voltage charging post input connections (102, 104) for an input DC voltage (VE) with a first voltage range provided by a central unit; a first DC voltage converter (106; 302) for converting the input DC voltage (VE) into a output DC voltage (VA) with a second voltage range; two DC voltage charging post output connections (108, 110) for providing the output DC voltage (VA) to the electric vehicle; and a control unit (112) with a first communication interface (114) for communication between the DC voltage charging post (100; 200; 300) and the central unit.

Claims

1. A central unit, which comprises and controls a plurality of DC voltage charging posts for charging electric vehicles, wherein the plurality of DC voltage charging posts comprise in each case: two DC voltage charging post input connections for an input DC voltage (VE) with a first voltage range provided by the central unit; a first DC voltage converter for converting the input DC voltage (VE) into an output DC voltage (VA) with a second voltage range; two DC voltage charging post output connections for providing the output DC voltage (VA) to the electric vehicles; a control unit with a first communication interface for communication between the plurality of DC voltage charging posts and the central unit; and a second DC voltage converter, which is connected selectively in parallel or in series to the first DC voltage converter, wherein a series connection achieves an addition of the output DC voltage and a parallel connection achieves an increase in an output DC current of the first DC voltage converter and the second DC voltage converter.

2. The central unit according to claim 1, wherein the control unit transmits or receives via the first communication interface at least one of the following items of information: status of the plurality of DC voltage charging posts, data regarding the maximum power outputted from the plurality of DC voltage charging posts, charging energy value, charging time value, electric vehicle identification information, and software update data.

3. The central unit according to claim 1, wherein the control unit supports a serial communication standard, in particular ethernet, at the first communication interface.

4. The central unit according to claim 1, wherein the control unit includes a second communication interface for communication between the plurality of DC voltage charging posts and the electric vehicle.

5. The central unit according to claim 4, wherein the control unit supports at the second communication interface at least two different communication protocols at one charging point.

6. The central unit according to claim 5, having a third DC voltage converter and a fourth DC voltage converter, wherein all DC voltage converters are selectively connected in parallel or in series.

7. The central unit according to claim 1, having a switch matrix which is connected with the control unit, with at least one input connection of each DC voltage converter and with the DC voltage charging post input connections, wherein the control unit controls the switch matrix such that all DC voltage converters are connected either in parallel or in series.

8. The central unit according to claim 1, having an isolation measuring unit which is connected to the DC voltage charging post input connections and to earth, wherein the isolation measuring unit measures isolation of the DC voltage charging post to earth and, depending on the measurement, disconnects the plurality of DC voltage charging posts electrically from the electric vehicle.

9. The central unit according to claim 1, having a power measuring unit which is connected to the DC voltage charging post input connections and which determines the power outputted to the electric vehicle and/or the charging time.

10. The central unit according to claim 1, having a temperature measuring unit which is configured to control the power output of the plurality of DC voltage charging posts depending on the measured temperature.

11. The central unit according to claim 1, having at least one main switch, which is connected in series between the first DC voltage converter and one of the DC voltage charging post input connections, wherein the main switch is configured to connect the first DC voltage converter selectively with one of the DC voltage charging post input connections, or to disconnect it therefrom.

12. The central unit according to claim 11, wherein the at least one main switch is controlled depending on an emergency off-signal, a system error signal, and isolation of the plurality of DC voltage charging posts to earth.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention are explained with reference to the drawings and the following description.

(2) FIG. 1 shows a DC voltage charging post according to the invention,

(3) FIG. 2 shows a further DC voltage charging post according to the invention and

(4) FIG. 3 shows a further DC voltage charging post according to the invention.

EMBODIMENT OF THE INVENTION

(5) FIG. 1 shows a DC voltage charging post 100 for charging a battery of an electric vehicle. The DC voltage charging post 100 includes two DC voltage charging post input connections 102, 104 for an input DC voltage V.sub.E with a first voltage range from 0 V to 200 V or from 0 V to 920 V, wherein ground potential 0 V is applied to the DC voltage charging post input connection 104. The input DC voltage is provided by a central unit and can be configured both +1000 V to earth or +−500 V to earth in the context of a DC bus supply.

(6) Furthermore, FIG. 1 shows a DC voltage converter 106 which forms a first DC voltage converter, for converting the input DC voltage V.sub.E into an output DC voltage V.sub.A with a second voltage range of 1000 V. The DC voltage converter 106 has moreover two DC voltage charging post output connections 108, 110 for providing the output DC voltage V.sub.A to the electric vehicle, wherein to the DC voltage charging post output connection 180 is applied a potential of 500 V and to the DC voltage charging post output connection 110 is applied a potential of −500 V.

(7) The DC voltage charging post 106 has furthermore a control unit 112 with an ethernet interface 114 for communication between the DC voltage charging post 106 and the central unit.

(8) FIG. 2 shows a DC voltage charging post 200 which includes the components 102 to 114 of the DC voltage charging post 100 as well as a system error switch 202, an emergency off-switch 204, and isolation switch 206 and two main switches 208, 210. The switches 202 to 206 are connected to the control unit 112. The main switches 208, 210 are connected in each case in series between the DC voltage charging post input connections 102, 100 and the DC voltage converter 106. If one of the switches 202 to 206 is actuated, they generate a signal which actuates the main switch 208, 210 such that the DC voltage converter 106 is disconnected or isolated electrically from the DC voltage charging post input connections 102, 104. The DC voltage charging post 200 includes an isolation measuring unit 212 which measures the isolation of the DC voltage charging post 200 to earth. If the measured isolation exceeds a predetermined threshold value, the isolation measuring unit 212 actuates the isolation switch 206 directly, i.e. without involving the control unit, wherein the isolation switch 206 in turn generates an isolation signal which actuates the main switches 208, 210 such that the DC voltage converter 106 is electrically disconnected or isolated from the DC voltage charging post input connections 102, 104.

(9) The emergency off-switch 204 can in an emergency be actuated by a DC current charging post user. The emergency off-switch 204 generates an emergency off-signal which actuates the main switches 208, 210 such that the DC voltage converter 106 is electrically disconnected or isolated from the DC voltage charging post input connections 102, 104.

(10) The system error switch 202 can be actuated by the control unit 112 and generate a system error signal which actuates the main switches 208, 210 such that the DC voltage converter 106 is electrically disconnected or isolated from the DC voltage charging post input connections 102, 104.

(11) The control unit 112 from FIG. 2 includes furthermore an electric vehicle communication interface 214 which forms a second communication interface for communication of the DC voltage charging post 200 with the electric vehicle. The electric vehicle communication interface comprises three protocol interfaces for the CCS protocol 216, for the Chademo protocol 218 and for the Tesla-Supercharger protocol 220. The three protocol interfaces are implemented as a computer 222. The computer 222 and/or the control unit 112 comprise a mini PC or a board computer, such as Raspberry Pi, Arduino or similar.

(12) The DC voltage charging post 200 includes furthermore a power measuring unit 224 which is connected to the DC voltage charging post input connections 102 and 104 and which determines the power outputted to the electric vehicle and/or the charging time. The charging energy value comprises the product of charging time or charging time value and charging power. The charging energy value and/or the charging time value serve as a basis for calculating a sales price for a battery charge and/or as customer information.

(13) FIG. 3 shows a DC voltage charging post 300 which comprises the components 102 to 114 of the DC voltage charging post 100, the components 202 to 224 of the DC voltage charging post 200 as well as a second DC voltage converter 302. The second DC voltage converter 302 is operated selectively connected in parallel or in series to the DC voltage converter 106.

(14) The DC voltage charging post 300 includes two switches 304, 306 which form a switch matrix 308. The switch 304 is connected to a first input connection of the DC voltage converter 106 and connects the first input connection of the DC voltage converter 106 selectively to a first input connection of the DC voltage converter 302 or to the DC voltage post input connection 104.

(15) The switch 306 is connected to the first input connection of the DC voltage converter 302 and connects the first input connection of the DC voltage converter 302 selectively to the first input connection of the DC voltage converter 106 or to DC voltage post input connection 102.

(16) The switches 304 and 306 are actuated by the control unit 112 such that the DC voltage converters 106, 302 are connected either in parallel or in series.

(17) A series connection of the DC voltage converters 106, 302 achieves an addition of the output DC voltages of the DC voltage converters 106, 302. A parallel connection of the DC voltage converters 106, 302 achieves an increase in an output DC current of the DC voltage converters 106, 302. An output DC current increase at the same output DC voltage V.sub.A effects an increase in the output power of the DC voltage converters 106, 302. Thus, the DC voltage charging post 300 can provide different charging voltages and charging powers. For example, when charging a lithium ion battery, charging is carried out initially with maximum charging power and the charging power is reduced in the further charging course.

(18) All switches 202 to 210 and 304, 306 can be designed as a relay, a contactor or semiconductor switch, e.g. FET or bipolar transistor.