WO2011065816A2

WO2011065816A2 - Electrical plug for charging an electric vehicle

Info

Publication number: WO2011065816A2
Application number: PCT/NL2010/000161
Authority: WO
Inventors: Antonius Bernardus Schaap
Original assignee: Ecofys Investments B.V.
Priority date: 2009-11-27
Filing date: 2010-11-24
Publication date: 2011-06-03
Also published as: NL1037508C2; WO2011065816A3

Abstract

The invention relates to an electrical plug for charging an electric vehicle, wherein the electrical plug has contact electrodes for contact with surface electrodes of a pavement element that is provided with at least two surface electrodes and the pavement element is arranged for connecting at least two of said at least two surface electrodes to the mains supply, wherein the electrical plug has an organ for improving the contact between the contact electrodes and the surface electrodes.

Description

Electrical plug for charging an electric vehicle

The present invention relates to an electrical plug for charging an electric vehicle.

The use, and therewith also the introduction, of electric cars and hybrid electric cars, which are cars having both an internal com- bustion engine as well as an electric motor, is hampered by the lack of proper charging stations. The known charging stations have the form of a charging pole containing a standard electrical socket for introducing the plug of the electric or hybrid car. These have the disadvantage that they constitute an obstacle in public space. Alter- natively, use can be made of a pavement element that is provided with at least two surface electrodes, which pavement element is arranged for connecting at least two of said at least two surface electrodes to the mains supply. Since the connecting point is a pavement element, it can be walked on and/or driven over without it forming an obstacle. The surface electrodes are arranged to cooperate with an electrical plug that can be connected to the vehicle to be charged or forms part thereof. The term surface electrode means that the surface electrodes will preferably not be positioned, at least hardly not, in a sunken position at the outside of the pavement element, and should this be the case, the discharge of water from the recessed part will be facilitated, for instance by means of one or more discharge ducts.

Because it concerns surface electrodes, these can be cleaned manually, for instance using a cloth, when they are wet and/or dirty, before applying the electrical plug.

This is, however, less user-friendly and further dirt and/or moisture may cause considerable local heating-up during charging, in fact causing the plug to be welded fixed to the pavement element.

The present invention aims to reduce this problem and to reduce the likelihood of getting it welded fixed.

Thus, the present invention relates to an electrical plug for charging an electric vehicle, wherein the electrical plug has contact electrodes for contact with surface electrodes of a pavement element which is provided with at least two surface electrodes and the pavement element is arranged for connecting at least two of said at least two surface electrodes to the mains supply, wherein the electrical plug has an organ for improving the contact between the contact electrodes and the surface electrodes.

Thus, a better contact between the contact electrodes and the surface electrodes can be realized.

Within the scope of the present invention an electric vehicle is a vehicle for use on the public road for conveying one or more persons and/or load. A typical usable pavement element has a plurality of sides, wherein a first side of the pavement element is provided with the at least two surface electrodes and the pavement ele- ment is arranged for connecting, via a second side, at least two of said at least two surface electrodes to the mains supply. These may be provided on the first side in such a way that an accumulation of water on and against the electrodes is avoided, as far as this water could lead to the flow of an electrical current between electrodes, in particular short circuit. The pavement element that can be used with the electrical plug according to the invention is a street tile, pavement tile or a curb stone, and will be used instead of an ordinary street tile, pavement tile or curb stone. Electricity reaches the pavement element via a second side, which in practice after lay- ing will be the underside of the pavement element, although in case of a curb stone it may also be a long side opposite the first (long) side. The term plurality in general means six, but aberrant numbers are possible, for instance because of cantings, roundings or when the pavement element is an ornamental tile. Thus, the number may be higher or lower than six. It is preferred that the surface electrodes lie in the plane of the first side. In case of a tile the surface electrodes may protrude somewhat from the plane of the first side, yet also in this case it will be taken care of that water can flow away along the surface electrodes of the pavement element. For a va- riety of reasons it goes without saying that for a pavement element that has been placed, a charging voltage will be on the electrodes during charging only. This can be realized in a variety of ways. It is possible that the pavement element itself has no organ at all to effectuate this. It is known to transmit signals such as pulses via an electric line, and such pulses can be generated by the electrical plug and/or by the vehicle and transmitted via the electrical plug and be analyzed remotely from the pavement element, for instance by an intermediate power supply station for the pavement element. This will indicate that an electrical plug is present and that a charging voltage may be applied. Nevertheless, a number of advantageous embodiments is conceivable wherein the tile has one or more organs for facilitating the charging process . The pavement element may have a sensor for detecting the presence of an electrical plug and/or a vehicle to be charged. Thereby any voltage on the pavement element and the exposure thereto of third parties can be avoided. Advantageously, the sensor is a magnetic sensor. The likelihood of the presence of a magnetic field of sufficient strength is very small, allowing to pro- vide a high degree of safety. With a magnetic sensor having a mechanical arm, this may be mounted such that in a lowermost position of the mechanical arm it will not allow voltage on the surface electrodes, whereas in a relatively higher position of the arm it will. Thus, in case of a defect in the sensor this cannot result in an electrical potential on the surface electrodes.

The organ is preferably an organ that is arranged to be capable of improving the contact between the contact electrodes and the surface electrodes after stationary placing of the electrical plug against the pavement element in an aligned state of the contact elec- trodes and the surface electrodes.

Thereby surfaces of the contact electrodes and/or the surface electrodes may be cleaned very specifically and it is avoided that dirt or the like is moved from a location where it does not interfere, to a location between the contact electrodes and the surface electrodes.

A preferred embodiment of the electrical plug is characterized in that the contact electrodes of the electrical plug are selected from i) a pressure spring, and ii) a brush that has electrically conductive hairs.

Thus, also in case of dirt on the electrodes of the pavement element a proper electrical contact can be ascertained. The electrical plug has a front side which, when connected to the pavement element, faces the first side. The pressure spring will preferably run with the centreline thereof parallel to the front side. Since adja- cent windings are spaced out, dirt particles such as grains of sand will be pushed aside and water may evaporate more easily, for instance accelerated by a fan that circulates air under the plug. The number of conductive hairs or threads of the brush will be at least two, but in practice will be a much higher number.

At least one contact electrode of the electrical plug may be a driven contact electrode, such as a contact electrode driven by a mo- tor .

With a motor being the organ, a proper contact with an electrode of the pavement element can be ascertained.

Alternatively or in addition, the electrical plug according to the invention may be characterized in that the electrical plug is provided with a cleaning element selected from a fan, a heating element, . a driven wiper and a driven brush for cleaning the electrodes of the pavement element.

Thus, the effects of dirt and/or moisture can be limited and the charging may possibly start sooner.

For connecting with the pavement element according to the invention, the electrical plug according to the invention is preferably characterized in that the electrical plug has at least one connecting element selected from a permanent magnet and a ferromagnetic element.

This connecting element then cooperates with a corresponding connecting element in the pavement element. The cooperation between the connecting elements brings about an easy and accurate positioning of the electrical plug relative to the pavement element, whereby the surfaces to be cleaned can be treated accurately using the organ. The magnetism can also be used to indicate that an electrical plug is present and that electricity may be transmitted via the pavement element, in other words, it may form part of the sensor for detecting the presence of an electrical plug and/or a vehicle to be charged of the embodiment discussed above.

According to an advantageous embodiment the electrical plug is arranged to withstand a downward force exerted on the electrical plug of at least 150 kg.

According to an advantageous embodiment the electrical plug is provided with a handle for detachably securing the electrical plug.

Preferably, the handle can be secured by means of a lock as a result of which third parties cannot detach it. The handle will actuate at least one movable arm which will permit the electrical plug to engage with the pavement element. The engagement may take place . on opposite sides of the pavement element, but for instance also with holes made in the pavement element. In this way also an accurate positioning may be accomplished.

This permits placing the vehicle to be charged on the plug, or part thereof, as a result of which the plug cannot be removed by mis- creants. The sensor discussed in conjunction with the pavement element for detecting whether an electrical plug is connected may be, if so desired, a pressure sensor or force sensor (such as a strain gauge) , although in general it will be undesirable if this would be the only detection.

Finally, the invention relates to three important forms of application of which the electrical plug will form a part of, viz. an extension cable, an adapter and an electric vehicle. For each of these embodiments it applies that these may be arranged to deliver a fluid to the pavement element, this is done preferably under an ele- vated pressure. The fluid may eg. be compressed air, but may also be a cleaning fluid such as water.

The present invention will now be illustrated by schematic drawings, where

fig. 1 shows a pavement element with an electrical plug;

fig. 2 shows a pavement element with a magnetic sensor;

fig. 3 shows an electrical plug with contact electrodes in the form of spiral springs;

fig. 4 shows an electrical plug with contact electrodes in the form of brushes;

fig. 5 shows an electrical plug with driven contact electrodes; fig. 6 shows a pavement element with an electrical plug with driven contact electrodes;

fig. 7 shows an electrical plug with a cleaning element for dispelling moisture;

fig. 8 shows a pavement element with an electrical plug with a handle for detachably securing the electrical plug;

fig. 9 shows an electrical plug which forms part of an electrically driven vehicle;

fig. 10 shows an electrical plug which forms part of an exten- sion cable that is connected to an electrically driven vehicle;

fig. 11 shows an electrically driven vehicle connected to an alternative plug according to the invention; and

fig. 12 shows an adapter. Fig. 1 shows a pavement element in the form of a tile 1 which has a three-wire cable 2 embedded in the tile 1, of which the wires 3 are connected to surface electrodes 4 on the top of the tile 1. The tile 1 further has 2 connecting elements in the form of embedded mag- nets 5, 6 whose function will be explained in the next paragraph.

Fig. 1 further shows an electrical plug 11 which has a three- wire cable 12 for connecting to an electrically driven vehicle, such as a car. The electrical plug 11 has contact electrodes 14 which make contact with the surface electrodes 4 of the tile 1 when connecting the electrical plug 11 to the tile 1. In the present application the term surface electrodes is used to indicate contact electrodes on a pavement element according to the invention, and is merely used in the application to easily distinct between electrodes of the pavement element and those of the electrical plug. The electrical plug 11 has magnets 15, 16. These magnets 15, 16 cooperate with the magnets 5, 6 of the tile 1 in order to connect the electrical plug 11 to the tile 1. The poles of the magnets 15, 16 may run parallel to each other in the same direction, in which case the plug 11 can be connected with the tile 1 in two positions, or run parallel in opposite direction to each other, in which case the plug 11 can be connected in but one position with the tile 1. In the latter case there wil be an increased simplicity of production for the producers of the pavement elements and the electrical plugs, since they need not worry about the absolute orientation of the poles, and merely need to make sure that both magnets are applied in an opposite pole direction. It goes without saying that more or fewer magnets may be used. Instead of two magnets also a single magnet can be used, for instance with a pole orientation parallel to the top of the tile 1. Problems with a pole orientation can also be avoided when one or more (but not all) magnets 5, 6, 15, 16 are replaced by a body of a ferromagnetic material, such as iron. The body can cooperate with a magnet regardless of the orientation of the latter.

Fig. 2 shows an alternative tile 21 which just like tile 1 is provided with a three-wire cable 23 and three surface electrodes 2 . For detecting the presence of an electrical plug such as electrical plug 11 of fig. 1 a magnetic switch 27 is provided. The presence of a magnetic field provided by the electrical plug makes that, in the embodiment illustrated here, an electrical connection is provided to one of the surface electrodes 24. It goes without saying that alternatives are also conceivable, such as activating a control circuit.

Fig. 3 shows an alternative electrical plug 31 with an electrical cable 32 and magnets 35, 36. The electrical plug 31 has two con- tact electrodes 34 in a spiral shape, wherein the centreline of the spiral shape after connecting to a pavement element runs substantially parallel to the side of the pavement element against which the electrical plug 31 is connected. Any dirt, such as grains of sand are pushed away by the shape of the windings, and thus interference of the electrical contact between the surface electrodes and the contact electrodes 34 is avoided. The spiral shape also offers the possibility of some deformation as a result of the force with which the electrical plug 31 is pressed against the pavement element, for instance by the magnets 35, 36.

Fig. 4 shows, as a variation of fig. 3, an electrical plug 41 having contact electrodes in the form of a brush 44 instead of contact electrodes in the form of a spiral.

In order to ensure contact between the surface electrodes 4 of the tile 1 with the contact electrodes, an electrical plug 51 (fig. 5) may be provided with contact electrodes 54 driven by means of motors 58. Contact may be established in a conventional manner by means of carbon brushes, something that needs no further elucidation.

Fig. 6 shows a pavement element in the form of a tile 61 that is provided with an embedded three-wire cable 62 connected to concen- trie surface electrodes 64. Reference numeral 161 indicates an electrical plug that is provided with a single motor 168, that drives a first arm 169a on which three contact electrodes 164 have been provided and a second arm 169b that is provided with a brush 167. With the latter, dirt can be wiped off the electrodes. In order to avoid the problem of cable twisting, the motor 168 will preferably make a reciprocating stroke movement, and is for instance a motor known for driving a windshield wiper.

Fig. 7 shows an electrical plug 71 that is provided with a two- wire cable 32 connected to contact electrodes 74. The plug is pro- vided with an air inlet pipe 72a and an air outlet pipe 72b. In the air inlet pipe 72a a fan 75 for the aspiration of outside air and a heating element 76 for the heating of the aspirated outside air are located. With this the surface electrodes of a pavement element can be dried, in case it is moist or wet, before applying voltage on the surface electrodes. A feed pipe 77 may be present for supplying a cleaning agent such as water or alcohol . To prevent the penetration of water a sealing ring, such as a rubber seal 79, may be present.

Fig. 8 shows a pavement element 81 wherein surface electrodes

84 are located on a section 82 that is higher than the surrounding side of the tile 81. The section 82 has a pilot edge 83 which cooperates with a pilot edge 183 of electrical plug 181. The pilot edges 83, 183 cooperate in order to facilitate the placing of the electri- cal plug 181 on the pavement element 81. The shape of the section 82 and that of the pilot edge 183 may be chosen such that the orientation of the electrical plug 181 is restricted, which contributes to the proper arrangement of the contact electrodes 184 against surface electrodes 84 that are connected to the two-core cable 89. The elec- trical plug 181 may be clamped to the pavement element 81 by means of a handle 185.

Fig. 9 shows an electrically driven vehicle in the form of a passenger car 91, that is charged via a pavement element in the form of a curb stone 93 provided with an electricity cable 92. The passen- ger car 91 is thereto provided with a plug 191 with a cable 192.

Fig. 10 shows an electrically driven vehicle in the form of a passenger car 101, that is charged via a pavement element in the form of a pavement tile 103 provided with an electricity cable 92. To this end, the passenger car 101 is provided with a plug 191 with a cable 192. For the connection to the pavement tile 103 an extension cable 195 is provided that at a first end thereof is provided with an electrical plug 196 for coupling to the electrical plug 191, and at a second end thereof is provided with an electrical plug 197 for connection to the pavement tile 103.

Fig. 11 shows a variation of fig. 9 wherein the electrical plug

191 is provided with a base in the form of a plate 199. The passenger car 91 is placed on the plate 199 with a tyre thereof. This prevents a third party from removing the electrical plug 191.

Fig. 12 substantially corresponds with fig. 4, but the electri- cal plug now is an integral part of an adapter 121, that has two bushings 122 for receiving a male plug.

Claims

ϊ 1 C L A I M S

1. Electrical plug for charging an electric vehicle, wherein the electrical plug (11) has contact electrodes (14) for contact with surface electrodes (4) of a pavement element (1) which is provided with at least two surface electrodes (4) and the pavement element (1) is arranged for connecting at least two of said at least two surface electrodes (4) to the mains supply, wherein the electrical plug has an organ for improving the contact between the contact electrodes (14) and the surface electrodes (4).

2. Electrical plug according to claim 1, wherein the organ is an organ that is arranged to be capable of improving the contact between the contact electrodes (14) and the surface electrodes (4) after stationary placing of the electrical plug against the pavement element (1) in an aligned state of the contact electrodes (14) and the surface electrodes (4).

3. Electrical plug according to claim 1 or 2, wherein the contact electrodes (14) of the electrical plug (31, 41) are selected from i) a pressure spring (34), and ii) a brush (44) that electrically con- ductive hairs.

4. Electrical plug according to any of the preceding claims, wherein at least one contact electrode of the electrical plug (51) is a contact electrode (54) driven by means of a motor (58) .

5. Electrical plug according to any of the preceding claims, wherein the electrical plug is provided with a cleaning element selected from a fan (75), a heating element (76), a driven wiper (169b, 167) and a driven brush (167) for cleaning the electrodes (64) of the pavement element (61) .

6. Electrical plug according to any of the preceding claims, wherein the electrical plug (11) has at least one connecting element (15, 16) selected from a permanent magnet and a ferromagnetic element.

7. Electrical plug according to any of the preceding claims, wherein the electrical plug (191) is arranged to withstand a downward force exerted on the electrical plug of at least 150 kg.

8. Electrical plug according to any of the preceding claims, wherein the electrical plug (181) is provided with a handle (185) for detach- ably securing the electrical plug (181).

9. Electrical plug according to any of the preceding claims, wherein the electrical plug (71) is arranged for delivering a fluid.

10. Electrical plug according to any of the preceding claims, wherein the electrical plug (197) forms part of an extension cable (195).

11. Electrical plug according to any of the preceding claims, wherein the electrical plug forms part of an adapter (121).

12. Electrical plug according to any of the preceding claims, wherein the electrical plug (191) forms part of an electrically driven vehi- cle (91)).