WO2021051233A1

WO2021051233A1 - Stationary charging arrangement and method for charging

Info

Publication number: WO2021051233A1
Application number: PCT/CN2019/105944
Authority: WO
Inventors: Hui Zhao; Gunnar Asplund
Original assignee: Elways Ab
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2021-03-25
Also published as: EP4031400A4; EP4031400A1

Abstract

A stationary charging arrangement for charging a battery or a set of batteries of an electrically propellable road vehicle while the vehicle is stationary. The arrangement comprises a rail element having at least one electric conductor extending in a lengthwise direction thereof, and a current collector adapted to co-act with the rail element, the electric conductor being arranged in at least one groove in the rail element and being adapted to be put under voltage, the current collector being connectable to the vehicle and being displaceable vertically and laterally to connect mechanically and electrically with the at least one electric conductor of the rail element for supplying electric power the vehicle. The rail element is adapted to be located in or on a parking lot on which the vehicle is parked. A system comprising such a charging arrangement and a corresponding method are also provided.

Description

STATIONARY CHARGING ARRANGEMENT AND METHOD FOR CHARGING

TECHNICAL FIELD

The invention relates to a stationary charging arrangement and a method for charging a parked electrically propellable road vehicle.

BACKGROUND

Concerns about the environmental impact of combustion of fossil fuels have led to an increased interest in electric vehicles, which have several potential benefits compared to vehicles with conventional internal combustion engines, including: a significant reduction of urban air pollution, as they do not emit harmful tailpipe pollutants from the on-board source of power at the point of operation; reduced greenhouse gas emissions from the on-board source of power, depending on the fuel and technology used for electricity generation and/or charging the batteries and reduced dependency on fossil fuels with increasingly variable supply and fluctuating prices.

However, the expense, weight and limited capacity of the lithium-ion battery packs of today limit widespread use of electric power as the main source of power in vehicles.

WO 2011/123049 proposes complementing the battery of the electric vehicle with electric feeding of the vehicle while driving. A system is disclosed for electric propulsion of a vehicle along a road comprising rail elements/structures having grooves provided with electric conductors therein that may be put under voltage and located in longitudinal tracks or channels in the road. The vehicle is equipped with a current collector which during contact with the electric conductors allows for transfer of electric power between the electric conductors and the vehicle to propel the vehicle and charge its battery or set of batteries.

The stretch of road carrying the rail elements is divided into electrically separated road sections oriented in series, whereby the rail elements are only put under voltage when a vehicle with its current collector passes the relevant road section.

Although the battery of the vehicle is charged while driving using such a system, it would also be advantageous to be able to charge the battery while parked, for instance at the parking lot at the residence of the vehicle owner. Charging of the vehicle using a conventional electric vehicle charging station installed at the parking lot together with associated cables is possible but involves quite high installation costs and the inconvenience of manually connecting and disconnecting a cable. Thus, there is a need for an improved stationary charging arrangement.

SUMMARY

An object of the invention is to solve or improve on at least some of the problems mentioned above in the background section.

These and other objects are achieved by the present invention by means of a stationary charging arrangement and a method for charging a battery or a set of batteries of an electrically propellable road vehicle according to the independent claims.

According to a first aspect of the invention, a stationary charging arrangement for charging a battery or a set of batteries of an electrically propellable road vehicle while the vehicle is stationary is provided. The arrangement comprises a rail element having at least one electric conductor, such as two or three electric conductors, extending in a lengthwise direction thereof, and a current collector adapted to co-act with the rail element, the electric conductor (s) being arranged in a respective groove of at least one groove in the rail element and being adapted to be put under voltage, the current collector being connectable to the vehicle and being displaceable vertically and laterally to connect mechanically and electrically with the at least one electric conductor of the rail element for supplying electric power the vehicle. The rail element is adapted to be located in or on a parking lot on which the vehicle is parked, i.e. is adapted to be wholly or partially recessed in the ground or arranged on the ground.

According to a second aspect of the invention, there is provided a system comprising a stationary charging arrangement according to the first aspect of the invention and an electrically propellable road vehicle comprising the current collector of the arrangement. The rail element is located in or on a parking lot on which the vehicle is adapted to be parked, and the rail element has a length shorter than that of the vehicle.

In other words, a stationary charging arrangement and a system comprising such an arrangement are provided, where the arrangement comprises a rail element having at least one electric conductor extending in a lengthwise direction thereof, which rail element is adapted to be located in or on a parking lot, and a current collector adapted to co-act with the rail element, and further with other elongated rail elements of corresponding cross-section, which may be longer or substantially longer than the rail element and being disposed in or on road sections to provide the vehicle with electric power while driving on the road sections. In this manner, the same current collector may be used both for stationary charging and for charging and propelling the vehicle while driving. Consequently, the vehicle can be conveniently charged while parked without having to connect and disconnect any charging cable.

In embodiments of the first and second aspects of the invention, the rail element has a length adapted to the length of the current collector, i.e. has a length sufficiently long to be able to receive the current collector, but significantly shorter than the vehicle in order not to expose the surroundings to unnecessarily long live electric conductors. Thus, the rail element of the stationary charging arrangement has a substantially shorter length than the elongated rail elements used for propelling and charging the vehicle while driving, which typically have a length considerably longer than the vehicle, as disclosed in WO 2011/123049.

In embodiments of the first and second aspects of the invention, the at least one groove has dimensions corresponding to IEC 60529. In other words, the groove has a width of equal to or less than 12 mm, and the at least one electric conductor is arranged at least 80 mm below an upper end of the groove. Since the electric conductor (s) of the rail element are supplied with electric current for long periods of time during stationary charging, safety is an important concern, which is ensured by choosing groove dimensions according to IEC 60529.

In embodiments of the first and second aspects of the invention, the rail element is provided with one, or preferably two or more electrically conducting ground conductors extending along the length direction, the ground conductor (s) being connected or connectable to ground potential, wherein the current collector is further adapted to be brought in electrical and mechanical contact with the at least one ground conductor to allow a ground connection to a chassis and/or body portion of the vehicle. This ground connection may be achieved, by the current collector having at least one ground contact element, each being configured to be brought in electrical and mechanical contact with a corresponding ground conductor, where the at least one ground contact element is electrically connected to a chassis and/or body portion of the vehicle. The ground contact elements may alternatively be arranged on a separate ground collector which is displaceable laterally and vertically in the same sense as the current collector. Such a ground collector may also be considered part of the current collector. The ground conductor (s) may be arranged at a top surface of the rail element, for instance between two grooves containing electric conductors. Alternatively, the ground conductor (s) , or at least contact surface (s) of the ground conductor (s) may be disposed on corresponding vertical side wall portion (s) of the at least one groove in said rail element, and the current collector may be configured to press the ground contact element (s) laterally towards said ground conductors to make contact therewith. In yet another embodiment, the at least one electrically conducting ground conductor may be provided in at least one groove in the rail, which at least one groove being separate from the at least one groove carrying the at least one electric conductor.

In embodiments of the first and second aspects of the invention, drainage means is arranged in fluid communication with a bottom portion of the groove (s) to drain water from the rail element. The drainage means may be in the form of a pipe or groove/channel which connects to a rainwater well, ditch or the like. In another embodiment, the drainage means may comprises a bilge pump or other pumping means configured to pump rain water from the bottom portion of the rail element to the parking lot surface, a well or an adjacent position.

In embodiments of the first and second aspects of the invention, the rail element is arranged recessed in a plate-shaped platform adapted to be placed on the parking lot, and being adapted to a vehicle width such that the vehicle can at least partly be driven up on the platform and be parked thereon while the current collector connects with the conductors of the rail element. In other words, the charging arrangement comprises a plate-shaped platform, where the rail element is recessed in the platform.

The platform is advantageously provided as a pre-assembled unit or set of units to allow convenient installation on the parking lot without having to perform any ground work. The platform may have a length adapted to a length of the vehicle, i.e. equal to or longer than a typical electric vehicle length to allow the whole vehicle to be parked on top of the platform. Alternatively, the platform may have a shorter length than the vehicle, for instance such that vehicle may be driven up on the platform and parked with two of the wheels on the platform. The platform may be manufactured at least in part from foamed concrete or a composite material to provide a platform of relatively low weight.

In embodiments, the platform is provided with electronic control means integrated in the platform, which electronic control means is configured to control charging of the vehicle and/or to optimize load balancing of the electric grid to which it is connected. This embodiment is advantageously combined with the above described embodiment where the platform is provided as a pre-assembled unit or set of units, to provide a plug-and-play charging arrangement which may be installed by a layman, possibly also connected to an already present two-or three-phase electric outlet, or possibly aided by an electrician to provide a permanent connection to the electric grid.

In embodiments, the platform is provided with the drainage means being arranged to drain water from the rail element to a peripheral portion of the platform, for example in the form of one or more pipes/conduits or channels/tracks arranged inclined from the bottom portion (s) of the rail element to peripheral portion (s) of the platform. Alternatively, the rail element itself may extend to a peripheral portion of the platform and have an inclined bottom portion, and/or be arranged inclined (either the rail element or the platform as a whole) , such that the rail element itself acts as the drainage means.

In embodiments, the arrangement further comprises a visual or physical stop indication indicating where the vehicle is to be positioned in the longitudinal direction to allow contact between the current collector and the at least one electric conductor. The stop indication may for example be a visual mark or a recess indicating an appropriate wheel position of the vehicle.

In embodiments, the arrangement further comprises means for generating a magnetic field and means for sensing a variation of a generated magnetic field, the means for generating and the means for sensing being attached directly or indirectly to the current collector, wherein the means for sensing is configured to generate a signal correlated to a horizontal distance between the means for generating a magnetic field and metal parts of the rail element, wherein the current collector is provided with actuating means configured to, in response to the signal, displace the current collector in the lateral direction to allow contact with the rail element, and to lower the current collector to make contact with the rail element while moving the current collector laterally until it slides into the at least one groove. The means for generating and sensing a magnetic field may comprise coils as described in applicants’ own patent EP2552735. In other embodiments, the arrangement comprises one or more optical sensors configured to generate a signal corresponding to the horizontal distance between the current collector and the rail element and/or a discrete signal indicating if the current collector is laterally aligned with the rail element or not.

In embodiments of the system according to the second aspect of the invention, the system further comprises at least one sensor configured to detect if the current collector is longitudinally aligned with the rail element, and wherein the vehicle comprises means for autonomously driving the vehicle in response to a signal from the at least one sensor. The sensors may be of the magnetic type of a similar type as described above, comprising means for generating a magnetic field and means for sensing a variation of a generated magnetic field, the means for generating and the means for sensing being attached to a lower portion of the vehicle, wherein the means for sensing is configured to generate a signal correlated to a longitudinal distance between the means for generating a magnetic field and metal parts of the rail element. In other embodiments, the arrangement comprises one or more optical sensors configured to generate a signal corresponding to the longitudinal distance between the current collector and the rail element and/or a discrete signal indicating if the current collector is longitudinally aligned with the rail element or not and/or a signal indicating a position relative reference marks on the ground. In other embodiments, the vehicle is provided with auto-breaking and/or autonomous driving functionality aided by distance measuring means such as a laser distance measuring device or a radar device. In such an embodiment, the system comprises a (vertically protruding) physical stop arranged at a front part of the parking lot, which physical stop is arranged at a longitudinal distance from the rail element such that when the vehicle is driven (manually or autonomously) forwardly until the vehicle is autonomously stopped by the auto-breaking or auto-driving functionality, the current collector is correctly positioned in the longitudinal direction relative the rail element. In this manner, it may be possible to use already present auto-breaking or autonomous driving functionality built in to the vehicle without further adaptation thereof for charging purposes.

According to a third aspect of the invention, a method for charging a battery or a set of batteries of an electrically propellable road vehicle while the vehicle is stationary is provided. The method comprises providing a system according to the second aspect of the invention, positioning the vehicle in its longitudinal direction to align the current collector longitudinally with the rail element, displacing the current collector in the lateral and/or vertical directions to make contact with electric conductor (s) of the rail element, and providing electric current to the electric conductors to charge the battery or set of batteries via the current collector.

According to a fourth aspect of the invention, a vehicle transport system is provided, the system comprising a system according to the second aspect of the invention and at least one elongated rail element having at least one electric conductor arranged in groove (s) thereof, said elongated rail element (s) having corresponding cross-section as the rail element located in or on the parking lot, said elongated rail elements being arranged consecutively along a roadway and being connectable to one or more vehicle-external power sources to supply the vehicle with electric power while driving on said roadway.

The features of the embodiments described above are combinable in any practically realizable way to form embodiments having combinations of these features. Further, all features and advantages of embodiments described above with reference to the first and second aspects of the invention may be applied in corresponding embodiments of the third and fourth aspects of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Above discussed and other aspects of the present invention will now be described in more detail using the appended drawings, which show presently preferred embodiments of the invention, wherein:

fig. 1 shows a schematic view of parts of an embodiment of a charging arrangement according to the first aspect of the invention;

fig. 2 shows a schematic cross section view of the rail element of the charging arrangement shown in fig. 1 together with a current collector;

fig. 3 shows a schematic view of parts of another embodiment of a charging arrangement according to the first aspect of the invention;

fig. 4 shows a schematic view of an embodiment of a system according to the second aspect of the invention, and

fig. 5 shows a flow chart illustrating an embodiment of a method according to the third aspect of the invention.

DETAILED DESCRIPTION

Fig. 1 shows a schematic view of parts of an embodiment of a charging arrangement according to the first aspect of the invention. A rail element 1 is shown recessed in a parking lot 5 (shown as a cut-out to illustrate the recessed rail element) to be flush with the ground level/surface of the parking lot. In this embodiment, the rail element is provided with two grooves 4a-b, each having an electric conductor arranged therein extending in a lengthwise direction of the rail element and its grooves. Drainage means in the form of a pipe 7 is arranged in fluid communication with bottom portions of the grooves of the rail element to drain water therefrom. It is understood that the pipe connects to a rainwater well, ditch or the like. As can be seen in fig. 1, and further in figs. 3-4, the rail element has a relatively short length, being sufficiently long to receive the current collector, but typically substantially shorter than the vehicle and the parking lot.

Fig. 2 shows a schematic cross section view of a rail element of the charging arrangement shown in fig. 1 together with a current collector 3 of the charging arrangement. The two grooves 4a-b are provided with a respective U-shaped electric conductor 2a-b arranged at the bottom of the grooves and being adapted to be put under voltage, which may be AC or DC voltage. The rail element is furthermore provided with an electrically conducting ground conductor 6 extending along the length direction in parallel with the electric conductors 2a-b. The ground conductor is arranged at a top portion of the rail between the two grooves 4a-b and is connectable to ground potential. The current collector 3 is provided with

collector arms

3a, 3d each having a contact portion arranged to provide sliding contact with a vertical wall portion of a respective electric conductor 2a-b, and is furthermore provided with

collector arms

3b, 3c each having a contact portion arranged to provide sliding contact with vertical wall portions of the common ground conductor 6. The

collector arms

3b, 3c are connectable to a chassis and/or body portion of the vehicle. In other embodiments, the contact portions may be configured as wheels providing a rolling contact with the conductors. The collector arms 3a-d are connected to a common arm-shaped contact device 3e (only a portion is shown in the figure) which is connectable to a vehicle to co-act with actuators or motors such that the current collector is displaceable vertically and laterally.

Fig. 3 shows a schematic view of parts of another embodiment of a charging arrangement according to the first aspect of the invention. This embodiment is similar to the embodiment shown in fig. 1, with the main difference being that the rail element 11 is not recessed in the ground, but is instead arranged recessed in a plate-shaped platform 18 adapted to be placed on the parking lot 15, and being adapted to a vehicle width such that the vehicle can be driven up on the platform and be parked thereon (see fig. 4) while the current collector connects with the conductors of the rail element 11. The rail element has the same cross-section as shown in fig. 2. In this embodiment, the platform is provided as a pre-assembled unit which has been conveniently installed on the parking lot without having to perform any ground work. The platform is manufactured from foamed concrete (except for the rail element) . The platform is provided with electronic control means integrated in the platform, which electronic control means is configured to control charging of the vehicle and/or to optimize load balancing of the electric grid to which it is connected. The electronic control means is connectable to the electric grid via a cable 19, which in this figure is illustrated with a plug, but may alternatively be permanently connected to the grid. The platform is provided with drainage means in the form of a pipe 17 arranged inclined from the bottom portion (s) of the grooves to a peripheral portion of the platform, as seen in fig. 3. The platform comprises a visual stop indication 110a-b in the form of lateral lines showing appropriate positioning of the rear wheels of the vehicle to allow contact between the current collector and the conductor of the rail element. Alternatively, a physical stop indication may be provided, for example in the form of platform recesses for the rear wheels.

Fig. 4 shows the same platform as in fig. 3 but is further shown with a vehicle 111 parked thereon, which vehicle is provided with a current collector 13 of the same type illustrated in fig. 2. As can be seen, the length and width of the platform is adapted to a typical electric vehicle such that the vehicle can be parked on top of the platform. It is noted that the platform in figs. 3-4 comprises a rail element which extends all the way to its front longitudinal end. It is understood that the electric conductors in the rail element do not necessarily extend all the way to the longitudinal end of the rail element, but may on the contrary only have a length adapted to the current collector. In other embodiments, the rail element is arranged at a distance from the longitudinal (and lateral) ends of the platform in a similar manner as shown in fig. 1.

Fig. 5 shows a flow chart illustrating an embodiment of a method according to the third aspect of the invention. The method comprises providing 21 a system according to the second aspect of the invention, positioning 22 the vehicle in its longitudinal direction to align the current collector longitudinally with the rail element, displacing 23 the current collector in the lateral and vertical directions to make contact with the conductor (s) of the rail element, and providing 24 electric current to the electric conductors to charge the battery or set of batteries via the current collector.

The description above and the appended drawings are to be considered as non-limiting examples of the invention. The person skilled in the art realizes that several changes and modifications may be made within the scope of the invention. For example, the rail element may be provided with only one groove provided with two or more electric conductors therein, or three or more grooves provided with at least one electric conductor and/or ground conductor in each. Furthermore, the contact portions of the conductors do not necessarily need to be vertical wall portions but may be bottom portions or any other part of the conductor (s) . Furthermore, the length of the rail element may vary within the scope of the invention.

Claims

Stationary charging arrangement for charging a battery or a set of batteries of an electrically propellable road vehicle while the vehicle is stationary, said arrangement comprising a rail element (1; 11) having at least one electric conductor (2a-b) extending in a lengthwise direction thereof, and a current collector (3) adapted to co-act with said rail element, said at least one electric conductor (2a-b) being arranged in at least one groove (4a-b; 14a-b) in said rail element and being adapted to be put under voltage, said current collector being connectable to said vehicle and being displaceable vertically and laterally to connect mechanically and electrically with said at least one electric conductor (2a-b) of said rail element for supplying electric power to said vehicle, said rail element being adapted to be located in or on a parking lot (5) on which the vehicle is adapted to be parked.
Stationary charging arrangement according to claim 1, wherein said rail element (1) and/or said at least one electric conductor has a length adapted to the length of the current collector (3) .
Stationary charging arrangement according to claim 1 or 2, wherein said at least one groove (4a-b; 14a-b) has a width and said at least one electric conductor is disposed in the at least one groove, to conform with IEC 60529.
Stationary charging arrangement according to any of the preceding claims, wherein said rail element (1; 11) is provided with at least one electrically conducting ground conductor (6) extending along said length direction, said ground conductor being connected to ground potential, wherein said current collector (3; 13) is further adapted to be brought in electrical and mechanical contact with said at least one ground conductor (6) to allow a ground connection to a chassis and/or body portion of said vehicle.
Stationary charging arrangement according to any of the preceding claims, wherein drainage means (7) is arranged in fluid communication with a bottom portion of said at least one groove to drain water from said rail element.
Stationary charging arrangement according to any of the preceding claims, wherein said rail element (11) is arranged recessed in a plate-shaped platform (18) adapted to be placed on said parking lot (15) , and being adapted to a vehicle width such that said vehicle can at least partly be driven up on said platform and be parked thereon to allow said current collector (13) to connect with said rail element.
Stationary charging arrangement according to claim 6, wherein said platform (17) is provided as a pre-assembled unit or set of units.
Stationary charging arrangement according to claim 6 or 7, wherein electronic control means configured to control charging of said vehicle is integrated in said platform (17) .
Stationary charging arrangement according to any of claims 6-8 as dependent on claim 5, wherein said platform is provided with said drainage means (17) being arranged to drain water from said rail element (11) to a peripheral portion of said platform.
Stationary charging arrangement according to any of the preceding claims, further comprising a visual or physical stop indication (110a-b) indicating where the vehicle is to be positioned in the longitudinal direction to allow contact between the current collector and the at least one electric conductor.
Stationary charging arrangement according to any of the preceding claims, further comprising means for generating a magnetic field and means for sensing a variation of a generated magnetic field, said means for generating and said means for sensing being attached directly or indirectly to said current collector, wherein said means for sensing is configured to generate a signal correlated to a lateral or horizontal distance between the means for generating a magnetic field and metal parts of the rail element, wherein said current collector is provided with actuating means configured to, in response to said signal, displace the current collector in the lateral direction to make contact with the rail element, and to lower the current collector to allow contact with the rail element while moving the current collector laterally until it slides into said at least one groove.
Stationary charging arrangement according to any of the preceding claims, further comprising means for detecting the presence of a vehicle, for example an RFID or magnetic sensor, said arrangement being configured to connect electric current to said at least electric conductor solely when said means for detecting indicates that a vehicle is present.
System comprising a stationary charging arrangement according to any of the preceding claims and an electrically propellable road vehicle (111) comprising said current collector (13) , wherein said rail element (11) is located in or on a parking lot (15) on which the vehicle is adapted to be parked, and wherein said rail element and/or said at least one electric conductor has a length shorter than that of the vehicle.
System according to claim 13, further comprising at least one sensor configured to detect if said current collector is longitudinally aligned with said rail element, and wherein said vehicle comprises means for autonomously driving the vehicle in response to a signal from said at least one sensor.
Method for charging a battery or a set of batteries of an electrically propellable road vehicle while the vehicle is stationary, said method comprising:

- providing (21) a system according to any of claims 13-14;

- positioning (22) the vehicle in its longitudinal direction to align said current collector longitudinally with said rail element;

- displacing (23) the current collector in the lateral and vertical directions to make contact with the rail element, and

- providing (24) electric current to said electric conductors to charge said battery or set of batteries via said current collector.