SE538900C2

SE538900C2 - System and method of electrical feeding of a vehicle

Info

Publication number: SE538900C2
Application number: SE1550505A
Authority: SE
Inventors: Asplund Gunnar
Original assignee: Elways Ab
Priority date: 2015-04-27
Filing date: 2015-04-27
Publication date: 2017-01-31
Also published as: SE1550505A1; WO2016174030A1

Abstract

ABSTRACT According to the invention, there is provided a system (1) for electrical feeding of avehicle (2), which system comprises at least one suspended rail element (3; 13; 23;33) and at least one contact device (6; 16; 26; 36). The rail element has at least oneelongated groove (4a-b; 14a-c; 24a-c; 34a-c) or channel extending along a length ofthe rail element, wherein electric conductors (15a-c) to be put under voltage arearranged therein. The at least one contact device is directly or indirectly connectableto the vehicle, wherein the contact device is displaceable relative said vehicle and isconfigured to mechanically and electrically connect with the rail element frombeneath in order to transmit electric current from said electric conductor to thevehicle. According to the invention, there is also provided a method for electricalfeeding of a vehicle, and use of at least one suspended rail element for electricalfeeding of a vehicle. (Fig. 1)

Description

SYSTEIVI AND METHOD FOR ELECTRICAL FEEDING OF A VEHICLE Field of the inventionThe invention relates to the field of electrical feeding of vehicles, and in particular electrical feeding of underground vehicles.

Background Concerns about the environmental impact of combustion of fossil fuels have led to anincreased interest in electric vehicles, which have several potential benefitscompared to vehicles with conventional internal combustion engines, including: asignificant reduction of urban air pollution, as they do not emit harmful tailpipepollutants from the on-board source of power at the point of operation; reducedgreenhouse gas emissions from the on-board source of power, depending on the fueland technology used for electricity generation and/or charging the batteries andreduced dependency on fossil fuels with increasingly variable supply and fluctuating pnces.

One disadvantage to be overcome is the limited range of existing electric vehiclesdue to limitations in battery capacity. This is a particularly significant disadvantage forheavy vehicles such as long haulage trucks as well as construction and miningvehicles.

WO 2010/140964 proposes a solution to this problem by feeding electric vehicleswhile driving. lt discloses a system for electric propulsion of a vehicle along a roadcomprising electric conductors in the shape of conducting rails that may be put undervoltage and located in longitudinal tracks or channels in the road. The vehicle isequipped with a current collector which during contact with the conducting rail allowsfor transfer of electric current between the conducting rail and the vehicle.

Although the solution according to WO 2010/140964 works well in many applications,it may not be suitable for very dusty or dirty environments such as mines. Since theconducting rail or track is located in the road, the excessive amount ofdirt, sand andstones present in a mine may accumulate in the track and greatly impair electric contact therein, and possible leading to the current collector getting stuck in thetracks or channels.

Summary An object of the present invention is to provide a system, a method and use forelectrical feeding of a vehicle which is suitable for use in an undergroundenvironment such as a mine. Another object is to provide such a system, method anduse with high safety.

These and other objects are achieved by the present invention by means of asystem, a method and use for electrical feeding of a vehicle according to theindependent claims. Preferred embodiments are defined in the dependent claims.

According to a first aspect of the invention, there is provided a system for electricalfeeding of a vehicle. The system comprises at least one suspended rail element andat least one contact device. The rail element has at least one elongated groove orchannel extending along a length of the rail element, wherein electric conductors tobe put under voltage are arranged therein. The at least one contact device is directlyor indirectly connectable to the vehicle, wherein the contact device is displaceablerelative said vehicle and is configured to mechanically and electrically connect withthe rail element, for example from beneath, in order to transmit electric current from said electric conductor to the vehicle. ln other words, the system comprises at least one suspended rail element, e.g. railelement(s) which is/are suspended or is adapted to be suspended from for example aceiling, wall or one or more stands, posts or the like. The rail element has at least oneelongated groove or channel extending along a length of the rail element. lnembodiments, the elongated groove or channel extends along the whole oressentially the whole length of the rail element. Electric conductors to be put undervoltage are arranged in the at least one groove or channel. For example, a systemcomprising a plurality of grooves or channels may have one, two or a plurality ofelectric conductors in each groove or channel, and a system comprising one grooveor channel may have two or a plurality of electrical conductors therein. The electricconductors may be arranged at a bottom portion or surface, or on vertical or side wa||(s) or portion(s), of the at least one groove or channel. The at least one contactdevice is directly or indirectly connectable to the vehicle, e.g. it comprises or isattached to connecting means, such as a connecting arm, which is directly connectedto the vehicle. The at least one contact device is configured to mechanically andelectrically connect with the rail element. For example, the contact device may beconfigured to allow at least a portion thereof to abut with at least the electricconductors to achieve a sliding electrical contact when to vehicle moves in order totransmit electric current from said electric conductor to the vehicle, either directly to atleast one electric motor which is arranged to propel the vehicle or indirectly, i.e. to forexample a battery or super capacitor arrangement. The at least one contact devicemay be configured to connect with the rail element from beneath, i.e. connect withthe rail element which is located above the contact device.

The invention is based on the insight that a suspended rail element, and the grooveor channel therein, is less exposed to dirt when it is suspended. The invention isfurthermore based on the insight that suspended rail elements having elongatedgroove(s) or channel(s) in which electrical conductors are arranged offers substantialsafety improvements over known technologies, such as suspended lines used with trolley buses. lt is understood that suspended rail element refers to a rail element which is hungfrom, or attached to, for example a ceiling, wall, or one or more stands or posts or thelike such that the rail element is at a distance or separated from the road. lt is furtherunderstood that the directions given throughout this text refer to an application wherethe vehicle is located with its wheels on a road, and the rail element is suspendedabove the vehicle and/or above the road. lt is also understood that rail element refers to an elongated element having a substantially greater length than width.

According to an embodiment, the at least one elongated groove or channel may bedownwardly facing when the at least one rail element is suspended, i.e. the at leastone elongated groove or channel is arranged facing in a direction having its greatest direction component along the plump line. ln embodiments, the contact device is displaceable upwards, downwards andlaterally. This is advantageous since it allows the contact device to connect to the rai| element regardless of their initial relative position. ln embodiments, the contact device further comprises guiding means arranged toguide the contact device in a direction towards the rai| element. The guiding meansmay comprise a guiding element provided with a recess, or with a U-shaped portion,having a width corresponding to that of said rai| element. The guiding element maybe described as being elongated or laterally extending. Such a guiding element isoperated by forcing it towards said rai| element, for example upwards, until it contactsthe rai| element, and thereafter the guiding element is displaced in a lateral directionthereof, e.g. in a perpendicular or substantially perpendicular direction relative the rai|element(s), until the rai| element and the recess or U-shaped portion having a widthcorresponding to that of said rai| element slide into, or engage with, each other. ln embodiments, the at least one rai| element is provided with one or more additionalelectric conductors at opposite sides of said at least one groove or channel, throughwhich conductors a current is adapted to pass for generating a magnetic field.Alternatively, the magnetic field may be generated by at least one permanent magnetarranged at opposite sides of the at least one groove or channel. The guiding meansmay be provided with at least one coil adapted to sense the magnetic field and avariation thereof, and the guiding means may further be provided with, or beconfigured to co-operate with, control means, such as an electronic control unit(ECU), which is configured to control actuating means, such as electric motors,arranged to displace said contact device in response to said sensed magnetic field. ln embodiments, the rai| element is provided with at least one electrically conductingground conductor provided on, or forming at least a portion of, an outer surface of therai| element, the ground conductor being connected or connectable to groundpotential. The ground conductor may be arranged to envelope said rai| element(apart from said at least one elongated groove) to provide a ground shield aroundsaid rai| element. The contact device may comprise at least one ground collector, forexample a sliding current collector, configured to be brought in electrical and mechanical contact with said ground conductor. ln embodiments, the rai| element is provided with three electric conductors, eachbeing connected to a phase of a three phase AC supply. ln other embodiments, therai| element is provided with two electric conductors being connected to a DC supply. ln embodiments, regardless if an AC or DC supply is used, the rai| element may beprovided with at least one additional electric conductor being a ground conductorarranged in at least one of the elongated groove(s) or channel(s), which groundconductor is connected or connectable to ground potential. ln embodiments, the rai| element comprises of a plurality of consecutively arrangedrai| element sections, wherein end portions of adjacent rai| element sections areelectrically and mechanically releasably connected together. This is advantageoussince the rai| element may be conveniently mounted or suspended by suspending ormounting one rai| element section at a time, and may also be convenientlydismounted when the system is to be used in for example another mine tunnel. Therai| element and rai| element sections may be attached to the ceiling using forexample expander bolts in drilled holes in the ceiling.

According to a second aspect of the invention, there is provided a method forelectrical feeding of a vehicle having at least one electric motor arranged to propelthe vehicle. The method comprises: - suspending at least one a rai| element from a ceiling, wall or one or morestands, posts or the like, the rai| element having at least one elongated grooveor channel extending along a length of said rai| element, wherein at least oneelectric conductor is arranged therein; - connecting at least one contact device to the vehicle, the contact device beingdisplaceable relative said vehicle; - displacing the contact device in a direction towards said rai| element, forexample from beneath, such that said contact device connects mechanicallyand electrically with said rai| element; and - supplying electric current to the at least one electric conductor whereby the electric current is transmitted to the vehicle via said contact device. ln embodiments of the method according to the second aspect of the invention, thestep of suspending comprises suspending the at least one rai| element in a direction such that the elongated groove is downwardly facing. ln embodiments of the method according to the second aspect of the invention, thestep of displacing comprises displacing the contact device in a direction towards therai| element and at least partially into the at least one groove, for example frombeneath, such that the contact device connects electrically with the at least oneelectric conductor. ln other words, the contact device is displaced towards the rai|element, and at least a portion thereof is displaced into the at least one groove. Theat least a portion of the contact device preferably comprises at least one currentcollector which thereby connects electrically with the at least one electric conductor. ln embodiments of the method, where the rai| element is provided with at least oneelectrically conducting ground conductor provided on, or forming at least a portion of,an outer surface of the rai| element, and where the contact device comprise at leastone ground collector, for example a sliding current collector, the step of displacingfurther comprises displacing the contact device in a direction towards the rai| elementsuch that the ground collector connects electrically with the at least one groundconductor. ln embodiments of the method according to the second aspect of the invention,where the contact device comprises a guiding element provided with a recess, or witha U-shaped portion, having a width corresponding to that of the rai| element, the stepof displacing comprises displacing the contact device towards the rai| element untilthe guiding element contacts the rai| element, and thereafter displacing the guidingelement in a lateral direction thereof until the rai| element slides into the recess or U-shaped portion. ln other words, the contact device is displaced towards the rai|element, typically upwards, until the guiding element contacts the rai| element.Thereafter, the guiding element is displaced sideways or laterally, while the contactdevice including the guiding element is still being forced towards the rai| element,until the rai| element slides into the recess or U-shaped portion, i.e. the recess or U-shaped portion engages with the rai| element. ln embodiments of the method according to the second aspect of the invention, thestep of suspending comprises suspending a plurality of rai| element sectionsconsecutively in a row, such that the rai| element sections forms the rai| element,wherein an end portion of one of the rai| element sections is electrically andmechanically attached to an end portion of an adjacent rai| element section.

According to a third aspect of the invention, there is provided use of at least onesuspended rai| element for electrical feeding of a vehicle, wherein the rai| element issuspended from a ceiling, wall or one or more stands or posts, the rai| elementhaving at least one elongated groove or channel extending along a length of the rai| element, wherein at least one electric conductor is arranged therein. ln embodiments of the use according to the third aspect of the invention, at least onecontact device is used to transmit electric current from the electric conductor to thevehicle, wherein the contact device is directly or indirectly connected to the vehicle,and wherein said contact device is displaceable and is configured to mechanicallyand electrically connect with said rai| element, for example from beneath. The at leastone contact device may also be used to connect the vehicle to ground potential,where the contact device comprises at least one ground collector, for example asliding current collector, which is brought in electrical and mechanical contact with atleast one ground conductor of the rai| element, the at least ground conductor beingprovided on, or forming at least a portion of, an outer surface of the rai| element.Alternatively, the at least one ground conductor may be arranged in at least one ofthe elongated groove(s) or channel(s).

The features of the embodiments described above are combinable in any way to formembodiments having combinations of these features. Further, all features andadvantages of embodiments described in connection with the system according tothe first aspect of the invention may be applied in corresponding embodiments of themethod according to the second aspect of the invention, and also in correspondingembodiments of the use according to the third aspect of the invention, and vice VGFSG.

Brief description of the drawingsThese and other aspects of the present invention will now be described in more detailwith reference to the appended drawings, which show presently preferredembodiments of the invention, wherein: fig. 1 shows a schematic illustration of an embodiment of a system according tothe first aspect of the invention, where the system arranged in a mine tunnel; fig. 2 shows a schematic illustration of another embodiment of a systemaccording to the first aspect of the invention; fig. 3 shows a schematic illustration of yet another embodiment of a systemaccording to the first aspect of the invention, which system comprises a groundconductor; and fig. 4 shows a schematic illustration of a further embodiment of a systemaccording to the first aspect of the invention, wherein the contact device of thesystem comprises a guiding element.

Detailed description Figure 1 shows a schematic illustration of an embodiment of a system 1 according tothe first aspect of the invention, where the system is arranged in a mine tunnel. Avehicle 2 is arranged in the mine tunnel. A rail element 3 is suspended from theceiling of the mine tunnel. The rail element extends along the mine tunnel, i.e. in thedepth direction thereof, i.e. along the travel path or direction of the vehicle. The railelement has two elongated grooves or channels 4a-b extending along the length ofthe rail element (in the depth direction in the figure). One electric conductor (notshown in figure) put under voltage is arranged in each groove or channel. Theelongated grooves or channels 4a-b are downwardly facing, i.e. facing towards thevehicle 2 and towards the road on which the vehicle is standing on.

The system also comprises a contact device 6 which is connected to a roof portionthe vehicle 2 using a connecting arm 12. The contact device is displaceable upwards,downwards and laterally to mechanically and electrically connect with the rail elementfrom beneath, in order to transmit electric current from said electric conductor to thevehicle, either directly to at least one electric motor which is arranged to propel thevehicle or indirectly, i.e. to for example a battery or super capacitor arrangement. Thecontact device is displaced using the connecting arm 12 which is pivotably attached to the vehicle (backwards, forwards and sideways as seen in the figure). This isadvantageous since it allows the contact device to connect, or maintain a connection,to the rai| element even if the vehicle moves in the lateral direction and if the height ofthe tunnel varies. The contact device connects with the rai| element by beingdisplaced upwards such that each of two vertically upwards extending portions of thecontact device 6 enters a corresponding groove or channel 4a-b. Each verticallyupwards extending portion of the contact device comprises a current collector portionconfigured to connect electrically with the electric conductor in the groove or channel.

Figure 2 shows a schematic illustration of another embodiment of a system according to the first aspect of the invention.

A rai| element 13 is suspended from a ceiling or stand (illustrated by the horizontalline in the figure). The rai| element has three elongated grooves or channels 14a-cextending along the length of the rai| element (in the depth direction in the figure).Electric conductors 15a-c are arranged said grooves or channels, one at a bottomportion of each groove or channel 14a-c. ln other embodiments, the electricconductors may be arranged on for example side walls or portions of the at least one groove or channel. The elongated grooves or channels 14a-c are downwardly facing.

The system also comprises a contact device 16 which is connectable to a roof portiona vehicle 2 using for example a connecting arm corresponding to that shown in figure1. The contact device is displaceable upwards, downwards and laterally tomechanically and electrically connect with the rai| element from beneath, in order totransmit electric current from said electric conductor to the vehicle, either directly to atleast one electric motor which is arranged to propel the vehicle or indirectly, i.e. to forexample a battery or super capacitor arrangement. The contact device connects withthe rai| element by being displaced upwards such that each of three verticallyupwards extending portions of the contact device 6 enters a corresponding groove orchannel 14a-c. Each vertically upwards extending portion of the contact devicecomprises a current collector 11a-c configured to connect electrically with the electricconductor in the grooves or channels. ln the figure, the current collectors are in directcontact with corresponding electric conductors 15a-c. As the vehicle moves, the current collectors slides along the electric conductors in the grooves or channels,remaining in contact with the electric conductors.

Figure 2 also illustrates how the grooves or channels 14a-c are limited and separatedby four parallel side walls 13a-d and a top wall 13e and have essentially U-shapedcross-sections. The grooves or channels are thus adapted to support current-feedable and energizable electric conductors 15a-c arranged in the innermostportions of the grooves or channels and being in abutment with the top wall 13e. Therail element also comprises an outer cover 13f that surrounds the side walls 13a, 13fand the top wall 13e. The outer cover is adapted to form a strong shell that prevents, among other things, the rail element from being deformed.

Figure 3 shows a schematic illustration of yet another embodiment of a systemaccording to the first aspect of the invention, which system comprises a groundconductor. The embodiment in figure 3 corresponds to the embodiment shown infigure 2, but differs in that the rail element 23 is provided with an electricallyconducting ground conductor 29 provided around an outer surface of the rail elementto envelope said rail element (apart from the elongated grooves or channels 24a-c),the ground conductor being connected to ground potential. The ground conductorthereby provides a ground shield around said rail element. A further difference fromthe embodiment in figure 2 is that the contact device 26 comprises two groundcollectors 210a-b, being sliding current collectors, configured to be brought inelectrical and mechanical contact with corresponding and downwardly directedportions of the ground conductor 29. The contact device connects with the groundconductor by being displaced upwards such that the two vertically upwards extendingground collectors 210a-b abut with the ground conductor, e.g. downwardly facing portions thereof, to achieve electrical and mechanical contact therewith.

Figure 4 shows a schematic illustration of a further embodiment of a systemaccording to the first aspect of the invention, which system comprises a guidingelement. The embodiment in figure 3 corresponds to the embodiment shown in figure2, but differs in that the contact device 36 is provided with a guiding element 37which is connected to a connecting arm 312. The guiding element has a laterallyextending bar-shaped body having a U-shaped portion 38 in the middle thereof. The 11 U-shaped portion has a width corresponding to that of the rail element 33. Theguiding element is provided to guide the contact device by displacing or moving thecontact device towards the rail element 33 until the guiding element contacts the railelement, and thereafter displacing the guiding element in a lateral or sidewaysdirection thereof until the rail element slides into the U-shaped portion 38. ln thefigure, the contact device is located below the rail element 33, but is not centred therebelow. Thus, when the contact device including the guiding element is displacedupwards using the connecting arm 312, the rail element 33 will not fit into the U-shaped portion. Consequently, the contact device is moved laterally or sidewaysrelative the rail element, while simultaneously being forced upwards, until the contactdevice and rail element slide into each other, thereby causing the current collectors311a-c to enter corresponding grooves or channels 34a-c of the rail element, to makecontact with the electric conductors therein.

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 severalchanges and modifications may be made within the scope of the invention. Forexample, the number of grooves or channels may be changed, and the dimensionsand proportions thereof may also be changed. Further, the groove(s) or channel(s)do not necessarily have to be facing straight downwardly, i.e. along the plump line,but may be facing in practically any other direction. The scope of protection is determined by the appended patent claims.

Claims

1. System (1) for electrical feeding of a vehicle (2) comprising - at least one suspended rail element (3; 13; 23; 33) having at least oneelongated groove (4a-b; 14a-c; 24a-c; 34a-c) extending along a length of saidrail element, wherein electric conductors (15a-c) to be put under voltage arearranged therein, - at least one contact device (6; 16; 26; 36) being directly or indirectlyconnectable to said vehicle, wherein said contact device is displaceable andis configured to mechanically and electrically connect with said rail elementfrom beneath in order to transmit electric current from said electric conductorsto said vehicle,wherein said contact device further comprises guiding means arranged toguide the contact device in a direction towards said rail element, andwherein said guiding means comprises a guiding element (37) having alaterally extending body provided with a recess having a width correspondingto that of said rail element (33).

2. System according to claim 1, wherein said contact device (6; 16; 26; 36) isdisplaceable upwards, downwards and laterally.

3. System according to any one of the preceding claims, wherein said rail element(23) is provided with at least one electrically conducting ground conductor (29)provided on, or forming at least a portion of, an outer surface of said rail element,said ground conductor being connected to ground potential.

4. System according to claim 3, wherein said ground conductor (29) is arranged to,apart from said at least one elongated groove (24a-c), envelope said rail element(23) to provide a ground shield around said rail element.

5. System according to claim 3 or 4, wherein said contact device (26) comprises atleast one ground collector (210a-b) configured to be brought in electrical andmechanical contact with said ground conductor (29).

6. System according to any one of the preceding claims, wherein said rai| element (13) is provided with three electric conductors (15a-c), each being connected to a phase of a three phase AC supply.

7. System according to any one of claims 1-5, wherein said rai| element is provided with two electric conductors being connected to DC supply.

8. System according to any one of the preceding claims, wherein said rai| element comprises of a plurality of consecutively arranged rai| element sections, whereinend portions of adjacent rai| element sections are electrically and mechanically releasably connected together.

9. Method for electrical feeding of a vehicle (2), said method comprising: - suspending at least one a rai| element (3; 13; 23; 33) from a ceiling, wall,stand(s), post(s) or the like, said rai| element having at least one elongatedgroove (4a-b; 14a-c; 24a-c; 34a-c) extending along a length of said rai|element, wherein at least one electric conductor is arranged therein; - connecting at least one contact device (6; 16; 26; 36) to said vehicle, saidcontact device being displaceable relative said vehicle; - displacing said contact device (6; 16; 26; 36) in a direction towards said rai|element (3; 13; 23; 33) such that said contact device connects mechanicallyand electrically with said rai| element (3; 13; 23; 33); and - supplying electric current to said electric conductor whereby said electriccurrent is transmitted to said vehicle via said contact device, wherein said contact device (36) comprises a guiding element (37) having a laterally extending body provided with a recess having a width corresponding to that of said rai| element (33), and wherein said displacing comprises displacingsaid contact device towards said rai| element until said guiding element contactsthe rai| element, and thereafter displacing the guiding element in a lateral directionthereof until the rai| element slides into said recess.

10.Method according to claim 9, wherein said suspending comprises suspendingsaid at least one rai| element in a direction such that said elongated groove (4a-b;14a-c; 24a-c; 34a-c) is downwardly facing.

11.Method according to claim 10, wherein said displacing comprises displacing saidcontact device in a direction towards said rai| element and into said at least onegroove (4a-b) such that said contact device connects electrically with said at leastone electric conductor.

12.Method according to any one of claims 9-11, wherein said suspending comprisessuspending a plurality of rai| element sections consecutively in a row, such thatsaid rai| element sections form said rai| element, wherein end portions ofadjacent said rai| element sections are connected electrically and mechanically together.

13. Use of a system according to any of claims 1-8 for electrical feeding of a vehicle(2), wherein said rai| element is suspended from a ceiling, wall or one or morestands or posts, further comprising using said at least one contact device totransmit electric current from the electric conductor to the vehicle.