EP4690418A1

EP4690418A1 - Multi-vehicle charging arrangement

Info

Publication number: EP4690418A1
Application number: EP23731125.3A
Authority: EP
Inventors: Joao Rosa Dias; Hans-Christian Doht
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG; Siemens Corp
Priority date: 2023-05-26
Filing date: 2023-05-26
Publication date: 2026-02-11
Also published as: WO2024245526A1

Abstract

The invention relates to an electric vehicle charging arrangement (1) for charging a plurality of electric vehicles (2) and a method of operating such an arrangement (1). The electric vehicle charging arrangement (1) includes a plural number of charging outlets (3-1, 3-2,..., 3-n) each of which is connectable to a corresponding one of the plurality of electric vehicles (2). The charging arrangement (1) further comprises a number of first power modules (4) configured to provide at least a first amount of electric power and a set of first switches (5) each having a first control electrode connected to a control unit (8) and configured to selectively connect the number of first power modules (4) to the charging outlets (3-1, 3-2,..., 3-n). According to the invention the charging arrangement (1) further comprises a plurality of second power modules (6) each configured to provide at most a second amount of electric power lower than the first amount of electric power and a set of second switches (7) each having a second control electrode connected to the control unit (8) and configured to selectively connect the second power modules (6) to the charging outlets (3-1, 3-2,..., 3-n).

Description

Multi-vehicle charging arrangement

Technical Field

The invention relates to an electric vehicle charging arrangement for charging a plurality of electric vehicles and a method of operating such an arrangement .

Technical Background

Electric vehicles are expected to replace vehicles driven by internal combustion engines within the near future . For commercial applications such as bus or freight vehicle depots , there is a problem posed by the high charging power required to recharge large traction batteries of such heavy electric vehicles within the limited time such vehicles are supposed to be in the depot . Commonly, energy prices increase dispro- portionally with the amount of power consumed at a time . The higher the amount of power consumed, the higher the price per kWh . This is because of the stress that high transient loads put on the utility grid . For these reasons there is an interest in distributing power consumption for charging of a fleet of electric vehicles evenly over the available time for charging . For example , individual buses in a bus depot may be charged at di f ferent times during the night when the buses are not in service resulting in all buses being ready for service in the morning in accordance with the bus schedule . For this purpose , charging arrangements have been devised that allow connection of a plurality of electric vehicles at the same time but which will only charge a limited number of vehicles at the same time . This is commonly referred to as "sequential charging" . It was recognised that , in such a charging arrangement , the number of power modules provided can be reduced to correspond to the maximum number of vehicles charged concurrently in order to save cost . Commonly a switch matrix may be provided to route power from the power modules to the currently active charging outlet .

It is an obj ect of the invention to provide an improved electric vehicle charging arrangement . Furthermore , it is an obj ect of the invention to provide a method of operating such an improved charging arrangement .

The invention solves these and other obj ects of the invention by providing an electric vehicle charging arrangement as set forth in claim 1 and a method of operating such an electric vehicle arrangement as set forth in claim 12 .

Summary of the Invention

A first aspect of the invention provides an electric vehicle charging arrangement for charging a plurality of electric vehicles . The charging arrangement includes a plural number of charging outlets each of which is connectable to a corresponding one of the plurality of electric vehicles . The charging arrangement further comprises a number of first power modules configured to provide at least a first amount of electric power and a set of first switches each having a first control electrode connected to a control unit and configured to selectively connect the number of first power modules to the charging outlets . According to the invention the charging arrangement further comprises a plurality of second power modules each configured to provide at most a second amount of electric power lower than the first amount of electric power and a set of second switches each having a second control electrode connected to the control unit and configured to selectively connect the second power modules to the charging outlets . The charging arrangement of the invention has an advantage in that it allows for fast-charging any of the plurality of electric vehicles using the first power modules at any point in time while the electric vehicle is not in operation, e . g . a bus parked in the bus depot during the night . However, when fast-charging of a given vehicle completes , it will not be without power because the vehicle may be connected to one second power module . This is advantageous because many types of electric vehicles will consume power while they are still waiting for their schedule to start . One such example would be cooling or heating of a passenger cabin to a desired temperature ahead of departure for the convenience of passengers riding on the bus . Another example would be cooling trucks that are supposed to transport frozen goods . In a similar arrangement according to the prior art such vehicles would have to drain their traction battery for these purposes thus limiting their range and doing so in accordance with the amount of time from when charging finished to departure of the vehicle . Alternatively, the charging arrangement would have to leave the first power module (being the only type of power modules ) connected which would result in an inappropriate utilisation of the costly first power module designed to provide high charging powers and in a low energy ef ficiency when operated the power module at an ef fective power much below its maximum rated power . The arrangement of the invention overcomes these disadvantages of the prior art by connecting one second power module having a lower rated maximum power than the first power modules .

In a preferred embodiment of the charging arrangement the control unit is configured to connect a selected one of the charging outlets to either one or more first power modules or to one second power module . This provides an advantage of allowing di f ferent ( fast- ) charging rates , e . g . , depending on the type of electric vehicle or a point within a charging cycle of the electric vehicle by combining a varying number of the first power modules while maintaining the number of switches in the set of second switches low and their arrangement simple .

Preferably, the plural number of charging outlets is greater than the number of first power modules . In such an arrangement many electric vehicles may concurrently wait for charging to commence which results in an economic operation and a cost ef fective charging arrangement .

Generally, a number of second power modules is preferably lower than or equal to the plural number of charging outlets . Moreover, a total number of first and second power modules may correspond to at least the plural number of charging outlets . In this case electric power may be provided to all electric vehicles connected to the charging arrangement .

Each charging outlet in the charging arrangement may comprise a first conductor connected to or connectable to one or more first power modules via the set of first switches and a second conductor isolated from the first conductor and connected to or connectable to one second power module via the set of second switches . In this way the second switches and the second power modules remain completely insulated from the current path of the first power modules which relaxes insulation requirements between the two types of power modules which may operate at di f ferent voltage ranges or power levels .

The first power modules may be adapted to provide a direct current output power and the second power modules may be adapted to provide an alternating current output power . In such a case the second power modules need not comprise any power conversion circuitry but may be fed directly from a low-voltage AC grid . Then, the second power modules may be confined to comprise only fuse , line protection and/or circuit breaker functionality and the like . Furthermore , many electric vehicles comprise an on-board AC bus to power auxiliary units such as air conditioning compressors , heaters etc . Alternatively, both the first power modules and the second power modules may be adapted to provide a direct current output power . In such a case the first power modules may be adapted to provide the direct current output voltage from within a first voltage range and the second power modules may be adapted to provide the direct current output voltage from within a second voltage range smaller than the first voltage range . Generally, a power module adapted to provide a smaller range of output voltages may be simpler and less expensive than one that supports a wider range of output voltages . The first power modules will be used for most or all of the charging cycle of the traction battery of the electric vehicle . The instantaneous voltage of the traction battery will vary with its state of charge wherein the voltage will increase with an increasing state of charge . The charging voltage applied to the traction battery will have to be set to a suitable voltage at each speci fic time in a charging cycle , e . g . , the charging voltage may be set at the instantaneous voltage of the traction battery plus an of fset voltage . Since the charging voltage varies over a wide voltage range , the first power modules should be adapted to provide output voltages from a relatively wide voltage range to enable fast charging . However, since the second power modules will commonly be used after charging has finished and provide power for other means than charging of the traction battery, the output voltage provided by the second power modules may be selected from a smaller voltage range . Since the instantaneous voltage of the traction battery will be high when charged, a lower boundary of the second voltage range is preferably higher than a lower boundary of the first voltage range .

The control unit of the charging arrangement may be adapted to never concurrently connect one of the first power modules and one of the second power modules to the same charging outlet . This provides for safe operation of the charging arrangement . The charging arrangement may comprise a plurality of dispensers connected to a central power station and each of which comprising at least one of the plural number of charging outlets , wherein the first power modules are located in the central power station and wherein the second power modules are located inside a corresponding one of the dispensers . Such an arrangement helps minimising paths between the first power modules and from the first modules to the charging outlets disposed on the dispensers as well as minimising the paths from the second power modules to their corresponding charging outlets . Furthermore , in such an arrangement the second power modules may be powered from an auxiliary power supply that is required for the dispenser to operate and would have to be provided anyway .

A second aspect of the invention provides a method of operating a charging arrangement according to the first aspect of the invention . The method includes steps of :

-- connecting a plurality of electric vehicles to a corresponding one of the plural number of charging outlets ;

-- controlling the set of first switches so as to provide power from the first power modules to a first subset of the plurality of electric vehicles ;

-- after providing power from the first power modules to the first subset of the plurality of electric vehicles , controlling the set of first switches so as to provide power from the first power modules to a second subset of the plurality of electric vehicles di f ferent from the first subset ; and -- controlling the set of second switches so as to provide power from the second power modules to a third subset of the plurality of electric vehicles before disconnecting the third subset of the plurality of electric vehicles from the charging outlets .

The method of the invention allows for cost ef fective sequential fast-charging of a fleet of electric vehicles ahead of their schedule and maintaining the traction batteries of the electric vehicles at their target state of charge despite of auxiliary units in the electric vehicles consuming power after fast-charging of the respective electric vehicle finished .

Short Description of the Drawings

The invention will now be described referring to drawings of preferred embodiments of the invention in which :

Fig . 1 shows a first embodiment of a charging arrangement in accordance with the invention;

Fig . 2 shows a second embodiment of a charging arrangement in accordance with the invention;

Fig . 3 shows a third embodiment of a charging arrangement in accordance with the invention; and

Fig . 4 shows a fourth embodiment of a charging arrangement in accordance with the invention .

Detailed Description of the Drawings

Fig . 1 shows a first embodiment of a charging arrangement 1 in accordance with the invention which comprises a plural number n of charging outlets 3- 1 , 3-2 , ..., 3-n and thus allows for connecting up to n electric vehicles 2 at the same time . Generally, the charging outlets 3- 1 , 3-2 , ..., 3-n may be adapted to connect to the electric vehicles 2 via a connector plug, a pantograph or wirelessly . In a speci fic charging arrangement 1 any selection of such means of connection may be combined to accommodate a vehicle fleet comprising di f ferent types and models of electric vehicles 2 .

In the example of Fig . 1 , the n charging outlets 3- 1 , 3-2 , ..., 3-n connect to first power modules 4 and second power modules 6 through as many power lines. First switches 5 are provided to selectively connect a number of first power modules 4 to one of the n power lines. It should be noted that there may be any number of first power modules 4 present in the charging arrangement 1 starting from one first power module 4. In any case, the simplified illustration of Fig. 1 is not to be understood as limiting the number of first modules 4 to just one. For example, the charging arrangement 1 of Fig. 1 may be provided with a plurality of first power modules 4, e.g., n first power modules 4 or more. Furthermore, while for sake of simplicity a single line is shown connecting the first power modules 4 to the first switches 5, a plurality of electric connections parallel to each other may be used for this purpose, e.g., a number of electric connections corresponding to the number of first power modules 4 in the charging arrangement 1. Similarly, second power modules 6 may connect to second switches 7 through a plurality of electric connections.

The first switches 5 may be configured to connect no more than one first power module 4 to a corresponding one of the charging outlets 3-1, 3-2,..., 3-n or to connect a plurality of first power modules 4 to a selected single one of the charging outlets 3-1, 3-2,..., 3-n.

In the first embodiment shown in Fig. 1 the first power modules 4 are powered from an AC (alternating current) grid 10. The first power modules may be AC//DC converters. Alternatively, the first power modules may be DC//DC converters. In this case a rectifier may be provided for rectifying the power received from the AC grid 10 and for supplying the DC//DC converters .

Generally, the second power modules 6 possess a lower rated maximum power than the first power modules 5. Their purpose is to provide only enough power to not cause the electric vehicles 2 to drain their traction batteries while idling and waiting for their departure. Usually there will be at most one second power module 6 per charging outlet 3- 1 , 3-2 3-n in the charging arrangement 1 .

The second power modules 6 of the first embodiment of the invention are also powered from the AC grid 10 . However, there may be intermediate functional blocks provided at the inputs of either the first power modules 4 or the second power modules 6 that trans form the AC voltage received from the AC grid 10 to a di f ferent voltage level for the two di f ferent types of power modules 4 , 6 . Alternatively or additionally the connection type may be di f ferent . For example , the first power modules 4 may be provided with a three-phase connection at their inputs while the second power modules 6 may only have a single-phase connection .

A control unit 8 is provided to control the first power modules 4 , the second power modules 6 , the first switches 5 and the second switches 7 . While only one control unit 8 is shown in any of the illustrated embodiments , the control unit 8 may consist of several control units distributed over the charging arrangement 1 that may cooperate or operate separate from each other .

In the embodiment of Fig . 1 , the first power modules 4 , the second power modules 6 , the first switches 5 and the second switches 7 may be arranged in a central power station, often called a "power block" . Such a power block may be located in a place away from the electric vehicles 2 in order to not obstruct movement of the electric vehicles 2 to and away from the charging outlets 3- 1 , 3-2 , ..., 3-n .

Fig . 2 shows a second embodiment of a charging arrangement 1 in accordance with the invention . While only two charging outlets 3- 1 and 3-2 are shown for ease of illustration, there may be a higher number of charging outlets present in the charging arrangement 1 . In the embodiment of Fig . 2 , the charging outlets 3- 1 , 3-2 are provided by means of dispensers 9 located in proximity of the electric vehicles 2 . Generally, a dispenser 9 may comprise only a limited portion of the actual charging hardware and thus assume a smaller form factor than a functionally complete charging station . For example , a dispenser 9 may provide for a user interface for authentication or other purposes .

The second power modules 6 of the charging arrangement 1 of the second embodiment are arranged inside the dispensers 9 , more precisely, there is one second power module 6 in each of the dispensers 9 . Accordingly, the second switches 7 for connecting the second power modules 6 to the charging outlets 3- 1 , 3-2 are also located inside the dispensers 9 . Only the more powerful and thus more complex and larger first power modules 4 are arranged centrally together with the first switches 5 for selectively connecting the first power modules 4 to the charging outlets 3- 1 , 3-2 via the dispensers 9 . Since the second power modules 6 will commonly be of smaller si ze than the first power modules 4 , they may fit more easily into the dispensers 9 . Furthermore , due to their lower maximum output power, the second power modules 6 may be powered from a relatively low power AC grid 10 that may also be required by other functional units (not shown) of the dispensers 9 .

The number of first power modules 4 of Fig . 2 may connect to a single direct current ( DC ) bus 11 even i f more than one first power module 4 is present in the system . The first switches 5 may selectively connect this DC bus 11 to either one of the dispensers 9 and thus to one of the charging outlets 3- 1 and 3-2 , respectively . However, i f more than two charging outlets 3- 1 , 3-2 are present in the charging arrangement 1 , it may be desirable to provide charging power to two or more charging outlets concurrently . In such a case it may be necessary to supply each electric vehicle 2 through a corresponding power line to comply with safety regulations demanding galvanic insulation among the electric vehicles 2 . The control unit 8 of Fig . 2 is shown to control the first power modules 4 , the first switches 5 , the second power modules 6 and the second switches 7 , however, this may be implemented di f ferently as already explain when referring to the embodiment of Fig . 1 .

Fig . 3 shows a third embodiment of a charging arrangement 1 in accordance with the invention . The third embodiment di ffers from the second embodiment in that the first switches 5 are also arranged inside the dispensers 9 alongside the second power modules 6 and second switches 7 . As with the second embodiment an approach to power distribution from the first power module ( s ) 4 to the dispensers 9 di f ferent from the DC bus 11 shown in the drawing may be chosen . In particular, a separate power supply line may be provided for powering the second power modules 6 and any potential other units inside the dispensers 9 that may require it . Furthermore , more than one DC bus 11 may be provided i f more than two charging outlets 3- 1 , 3-2 are present in the charging arrangement 1 and more than one charging outlet is to be connected to first power modules 4 at the same time .

Fig . 4 shows a fourth embodiment of a charging arrangement 1 in accordance with the invention . Contrary to the other embodiments of the invention shown in Figs . 1 through 3 where the first power modules 4 are arranged centrally, the first power modules 4 are arranged locally in a distributed manner . More precisely, in the fourth embodiment the first power modules 4 are arranged together with a corresponding one of the first switches 5 , the second power modules 6 and the second switches 7 in a respective charging stations 12 . Such a charging arrangement may be suitable for a comparatively low number of charging outlets 3- 1 , 3-2 where the required number of first power modules 4 does not become prohibitively high . In the example shown in Fig . 4 , the first switch 5 and the second switch 7 in a charging station 12 may be integrated into a single two-way switch which then provides the functionality of both the first switch 5 and the second switch 7 . At the same time the two-way switch makes sure that a first power module 4 and a second power module 6 will never be connected to the same charging outlet at the same time . While Fig . 4 shows a single control unit 8 , the control unit

8 may be implemented - as with all embodiments of the arrangement of the invention - as a distributed controller comprising a plurality of secondary control units which may or may not communicate with each other . In particular, there may be one secondary control unit in each of the charging stations 12 of the fourth embodiment of the charging arrangement 1 .

The invention has been described referring to various advan- tageous embodiments thereof . However, the examples shown and described are merely provided for better understanding of the invention and are not meant to limit the scope of the invention which is exclusively defined by the patent claims below .

Reference Numerals

1 charging arrangement

2 electric vehicle 3, 3-1, 3-2, ..., 3-n charging outlet

4 first power modules

5 first switches

6 second power modules

7 second switches 8 control unit

9 dispenser

10 AC (alternating current) grid

11 DC (direct current) bus

12 charging station

Claims

Patent claims

1. An electric vehicle charging arrangement (1) for charging a plurality of electric vehicles (2) , the charging arrangement (1) including a plural number of charging outlets (3-1, 3-2, ..., 3-n) each of which connectable to a corresponding one of the plurality of electric vehicles (2) , a number of first power modules (4) configured to provide at least a first amount of electric power, a set of first switches (5) each having a first control electrode connected to a control unit (8) and configured to selectively connect the number of first power modules (4) to the charging outlets (3-1, 3-2, ..., 3-n) , characterized by a plurality of second power modules (6) each configured to provide at most a second amount of electric power lower than the first amount of electric power and a set of second switches (7) each having a second control electrode connected to the control unit (8) and configured to selectively connect the second power modules (6) to the charging outlets (3-1, 3-2, ..., 3-n) .

2. The charging arrangement (1) of the preceding claim, wherein the control unit (8) is configured to connect a selected one of the charging outlets (3-1, 3-2,..., 3-n ) to either one or more first power modules (4) or to one second power module (6) .

3. The charging arrangement (1) of one of the preceding claims, wherein the plural number of charging outlets (3-1, 3-2,..., 3-n ) is greater than the number of first power mod- ules ( 4 ) .

4. The charging arrangement (1) of one of the preceding claims , wherein a number of second power modules (6) is lower than or equal to the plural number of charging outlets (3-1,

3-2, ..., 3-n) .

5. The charging arrangement (1) of claims 3 and 4, wherein a total number of first and second power modules (4, 6) corre- sponds to at least the plural number of charging outlets (3- 1, 3-2, 3-n) .

6. The charging arrangement (1) of one of the preceding claims, wherein each charging outlet (3-1, 3-2,..., 3-n ) comprises a first conductor connected to or connectable to one or more first power modules (4) via the set of first switches

(5) and a second conductor isolated from the first conductor and connected to or connectable to one second power module

(6) via the set of second switches (7) .

7. The charging arrangement (1) of one of the preceding claims, wherein the first power modules (4) are adapted to provide a direct current output power and wherein the second power modules (6) are adapted to provide an alternating current output power.

8. The charging arrangement (1) of one of the claims 1 through 6, wherein the first power modules (4) and the second power modules (6) are adapted to provide a direct current output power and wherein the first power modules are adapted to provide the direct current output voltage from within a first voltage range and the second power modules are adapted to provide the direct current output voltage from within a second voltage range smaller than the first voltage range.

9. The charging arrangement (1) of the preceding claim, wherein a lower boundary of the second voltage range is higher than a lower boundary of the first voltage range.

10. The charging arrangement (1) of one of the preceding claims, wherein the control unit (8) is adapted to never concurrently connect one of the first power modules (4) and one of the second power modules (6) to the same charging outlet (3-1, 3-2, ..., 3-n) .

11. The charging arrangement (1) of one of the preceding claims, comprising a plurality of dispensers (9) connected to a central power station and each of which comprising at least one of the plural number of charging outlets (3-1, 3-2, ..., 3- n) , wherein the first power modules (4) are located in the central power station and wherein the second power modules (6) are located inside a corresponding one of the dispensers (9) .

12. A method of operating a charging arrangement (1) according to one of the preceding claims including steps of: -- connecting a plurality of electric vehicles (2) to a corresponding one of the plural number of charging outlets (3-1, 3-2, ..., 3-n) ;

-- controlling the set of first switches (5) so as to provide power from the first power modules (4) to a first subset of the plurality of electric vehicles (2) ;

-- after providing power from the first power modules (4) to the first subset of the plurality of electric vehicles (2) , controlling the set of first switches (4) so as to provide power from the first power modules (4) to a second subset of the plurality of electric vehicles (2) different from the first subset; and

-- controlling the set of second switches (7) so as to provide power from the second power modules (6) to a third subset of the plurality of electric vehicles (2) before disconnecting the third subset of the plurality of electric vehicles (2) from the charging outlets (3-1, 3-2, ..., 3-n) .