WO2011077108A2

WO2011077108A2 - Vehicle charging apparatus

Info

Publication number: WO2011077108A2
Application number: PCT/GB2010/052046
Authority: WO
Inventors: John Holden
Original assignee: Hiltech Developments Limited
Priority date: 2009-12-21
Filing date: 2010-12-08
Publication date: 2011-06-30
Also published as: WO2011077108A3; GB0922199D0

Abstract

A charging apparatus for an electric vehicle having electric storage means, comprising an electrical power source provided remotely from the vehicle; a charging connector electrically connected to the power source having a substantially elongate and cylindrical charging portion comprising a primary coil;a complementarily shaped tubular receiving portion mounted on the vehicle and adapted to receive the charging portion and comprising a secondary coil so that when the charging portion is fully inserted in the receiving portion, the primary coil and secondary coil are electromagnetically coupled together to transmit electric power from the primary coil to the secondary coil by electromagnetic induction to charge the storage means of the electric vehicle;control means adapted to detect when the charging portion is fully inserted in the receiving portion and only allow transmission of electric power from the primary coil to the secondary coil based on said detection; and communication means adapted to transfer data from the vehicle to data storage means remotely located from the vehicle via the receiving portion and the charging portion.

Description

VEHICLE CHARGING APPARATUS

The present invention relates to a vehicle charging apparatus and in particular to an apparatus for charging an electric vehicle quickly, safely and efficiently.

For known environmental reasons, electric vehicles are becoming increasingly desirable. Such vehicles include one or more electric motors to drive the wheels via the vehicle transmission system. Typically, a number of onboard batteries power the motors and which require frequent re-charging.

A known method of re-charging an onboard fuel cell is by electromagnetic induction. As shown in Figure 1 , an electric power receiving portion 42, connected to a battery (not shown), is provided at a body of an electric vehicle 41 . Referring also to Figure 2, this power receiving portion 42 includes a secondary coil 44 provided in the vicinity of a recess 43 formed in the electric vehicle 41 , and a charging connector 45 is inserted into this recess 43. The charging connector 45 is connected via a cable 47 to a charging power source 46 provided in a garage or the like.

As shown in Figure 3, the charging connector 45 has a primary coil 48 contained in a connector housing 49 preferably made of a synthetic resin, and when the charging connector 45 is inserted into the recess 43, the primary coil 48 is electromagnetically coupled to the secondary coil 44, so that electric power is supplied from the charging power source 46, shown in Fig. 1 , to the battery via the charging connector 45 and the power receiving portion 42. The charging connector 45 is a paddle-shaped connector and is received into the correspondingly shaped recess 43 of the receiving portion 42. The receiving portion 42 is typically located on the front or rear of the vehicle 41 , such as the front or rear bumper or on top of the trunk or boot of the vehicle, as shown in Fig. 1 . This is to provide easy access to a user so the charging connector 45 can be inserted downwardly into the receiving portion 42 and removed upwardly therefrom after charging is complete.

However, the front and rear of the vehicle are more susceptible to dirt due to impact whilst moving forward and turbulence behind the vehicle. The ingress of dirt into the receiving portion 42 may damage the secondary coil 44 and adversely affect the performance of the charging apparatus.

Furthermore, the operation of electric vehicles is still less well established than conventional petrol and diesel vehicles, not only because of their performance differences but also because of the significantly different driving and user experience. One aspect of this is the experience of recharging the electric vehicle. The average user is used to filling up a conventional petrol or diesel vehicle by opening a filler flap, removing a filler cap, inserting a nozzle and filling up a fuel tank with fuel. Inserting a paddle-shaped charging connector 45 into a slotted receiving portion 42 located on the front or rear of a vehicle does not achieve this desirable 'refuelling' experience. Furthermore, the external appearance of the vehicle is adversely affected to accommodate the receiving portion 42 and the vehicle body 41 must be redesigned for the receiving portion 42 to be located and fitted thereon. This is undesirable for the end user and is costly to the manufacturing process. To charge an electric vehicle using a known charging apparatus as described above, the charging connector 45 must be inserted into the receiving portion 42 and the charging power source 46 switched on.

When the vehicle battery is fully charged, the user must switch off the charging power source 46. The user has no means of determining when the battery is fully charged from outside the vehicle. Also, to achieve maximum induction, the charging connector 45 must be fully inserted into the receiving portion 42 so the primary and secondary coils are fully aligned. If the charging connector 45 is not fully inserted into the receiving portion 42 or is accidentally moved out of full alignment, charging efficiency will be significantly reduced. Furthermore, the user interaction for switching the power source 46 on and off as desired creates a risk of electrocution or fire, for example, and if the user does not switch on the power source 46 there is no means of alerting the user to this and that their vehicle is not being re-charged.

A first aspect of the present invention provides a charging apparatus for an electric vehicle having electric storage means, comprising:

- an electrical power source provided remotely from the vehicle;

- a charging connector electrically connected to the power source having a substantially elongate and cylindrical charging portion comprising a primary coil;

- a complementarily shaped tubular receiving portion mounted on the vehicle and adapted to receive the charging portion and comprising a secondary coil so that when the charging portion is fully inserted in the receiving portion, the primary coil and secondary coil are

electromagnetically coupled together to transmit electric power from the primary coil to the secondary coil by electromagnetic induction to charge the storage means of the electric vehicle; - control means adapted to detect when the charging portion is fully inserted in the receiving portion and only allow transmission of electric power from the primary coil to the secondary coil based on said detection; and

- communication means adapted to transfer data from the vehicle to data storage means remotely located from the vehicle via the receiving portion and the charging portion.

The cylindrical and tubular configuration and engagement of the charging portion and the receiving portion provides a similar experience to that of re-fuelling a conventional petrol or diesel vehicle. Preferably the charging portion is a slightly curved cylindrical charging portion which is similar in appearance to the nozzle of a conventional petrol or diesel fuel pump. Suitably the charging connector may further comprise a handle which may also be similar in shape to a conventional fuel nozzle handle. This desirably ensures the refuelling experience for the electric vehicle user is substantially similar to that of refuelling conventional petrol and diesel vehicles. Preferably the receiving portion is adapted to be retro-fitted to the vehicle and further preferably provided behind an existing filler flap. This advantageously ensures the external appearance of the vehicle remains unchanged and the apparatus can easily be fitted to the vehicle without significant and costly modification to the vehicle body. Furthermore, the receiving portion is protected from rain, snow and the ingress of general dirt by the filler cap and is also tamper-proof.

Preferably the electric power transmitted from the primary coil to the secondary coil by electromagnetic induction to charge the power storage means of the electric vehicle is a high frequency AC power. Suitably the power transfer rating of the apparatus is from 1 kW to 15kW. Preferably the power transfer rating is from 3kW to 10kW. Suitably the charging apparatus comprises a first inverter remote from the vehicle to invert an input AC power from the power source to a high frequency AC power for power transmission from the primary coil to the secondary coil. Suitably the input AC power is a single phase AC mains utility supply of 1 10/240V, 50/60 Hz. Preferably the high frequency AC power is greater than 20 kHz and further preferably around 65 kHz.

Suitably the first inverter may be an AC/DC/AC inverter. Suitably the first inverter may be housed in a power source control box. The control box may be wall-mounted. Preferably an isolator or circuit breaker is provided between the power source and the first inverter and which may be provided in the control box or separate therefrom.

Suitably the charging apparatus comprises a second inverter to invert the high frequency AC power to a DC power output suitable for the power storage means. Preferably the DC power output is controlled. Suitably the second inverter is provided in the vehicle.

Suitably the power rating of the power storage means is from 330 to 450V. For example, the power storage means may comprise a 350V, 26.4 kWhr battery. Suitably, the power storage means may comprise a plurality of capacitors.

The power source may be connected to a "smart grid" having the ability to limit power transfer in accordance with power utility conditions by means of an intelligent monitoring system that monitors electricity flowing in the grid system. The smart grid may also incorporate the use of and/or integration of alternative sources of electricity such as solar and wind. When power is least expensive, the smart grid may make available charging that can be accepted at arbitrary hours in a domestic situation such as overnight, for example. At peak times, the smart grid may only delivery minimal energy to reduce demand on the grid.

The control means is adapted to detect when the charging portion is fully inserted in the receiving portion and allow transmission of electric power from the primary coil to the secondary coil based on said detection.

Transmission of electric power is only allowed when the charging portion is fully received by the receiving portion. Any significant movement disrupting alignment of the primary and secondary coils will cause the electric power transmission to be deactivated thereby providing a safe charging apparatus.

Preferably the control means comprises a capacitor-based tuned circuit for detecting when the charging portion is fully inserted in the receiving portion. Preferably the charging portion comprises a primary capacitor- based tuned circuit and the receiving portion comprises a secondary capacitor-based tuned circuit correspondingly tuned with the primary capacitor-based tuned circuit. Suitably the primary capacitor-based tuned circuit is provided at or near a free end of the cylindrical charging portion and the secondary capacitor-based tuned circuit is provided at or near the base of the tubular receiving portion.

When the charging portion is fully inserted into the receiving portion the control means detects this arrangement via the capacitor-based tuned circuitry and allows electric power transmission from the primary coil to the secondary coil for charging of the power storage means. Suitably a further solid state switch may alternatively or additionally detect when the charging portion is fully inserted into the receiving portion because of disruption of a capacitor based tuned circuit.

The control means is thereby adapted to automatically allow charging only when the charging portion is fully inserted into the receiving portion and automatically stop charging when the charging portion is not fully inserted into the receiving portion or when the charging portion is accidentally moved from a fully engaged position. This eliminates the risk to a user where the charging portion is pulled in the receiving portion by a person tripping over the electrical connection between the charging portion and the power source, for example. The risk of a user not fully inserting the charging portion into the receiving portion and affecting relatively slow and inefficient charging is also eliminated.

The charging apparatus comprises communication means adapted to transfer data from the vehicle to data storage means remotely located from the vehicle via the receiving portion and the charging portion.

Preferably a power source control box remote from the vehicle comprises the data storage means.

Preferably the data includes, but is not limited to, vehicle identification, battery health status and state-of-charge of the power storage means, vehicle mileage, for example. The data storage means may also store further data relating to the power source, such further data including, but not limited to, the status of the power source, its location, the amount of energy transferred, limitation of power, time and date, for example.

Such data may be used for diagnostic purposes and the communication means may utilise Bluetooth™ technology, for example. Preferably the control means is further adapted to monitor the charging state of the power storage means. Suitably when the power storage means is fully charged, the control means is adapted to automatically stop charging. Suitably a switch may be provided between the receiving portion and the second inverter and the control means may activate the switch to disconnect the receiving portion from the second inverter when the power storage means is fully charged. This automatic monitoring eliminates the requirement of user interaction whilst charging the vehicle and provides for a safer and more efficient charging apparatus.

Suitably the control means may also be adapted to determine if the vehicle is a fuel cell-only vehicle or a hybrid-electric vehicle and select a charging regime suitable for that type of vehicle.

Suitably the control means may be further adapted to detect apparatus operation time. The control means may comprise a form of timer. If the apparatus has been continuously operating for a determined period of time, the control means may limit the operation time to allow the apparatus to 'rest'. This eliminates overheating and damage to the apparatus and prevents wasted energy.

Suitably the control means may be further adapted to test the onboard circuitry for continuity and earth fault or short circuit conditions. In the event of a fault being detected, a fault indicator may be displayed to a user, such as a fault display on the vehicle dashboard.

Suitably the apparatus may comprise audible and/or visual means to indicate when the power storage means is being charged and/or when the storage means is fully charged. Suitably the audible and/or visual means may be provided on the charging connector, the receiving portion, the vehicle and/or the power source control box.

Suitably the charging connector and the receiving portion comprise each comprise a housing made from a reinforced polymer material to sealably contain the respective primary and secondary coils. Suitably the material is penetration, impact, corrosion and crush resistant and electrically isolates the user from the primary and secondary coils. Water and dirt ingress is also prevented. A suitable material is IP65.

Suitably when the tubular-shaped charging portion is inserted into the complementarily shaped receiving portion, a gap is provided

therebetween. Suitably the gap is around 2mm. A further aspect of the present invention provides an electric vehicle adapted for use with a charging apparatus as described above.

A further aspect of the present invention provides a method of charging an electric vehicle with a charging apparatus as described above.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying figures, in which:

- Figures 1 to 3 show a known electric vehicle charging apparatus as described above;

- Figure 4 is a schematic of the power source side including the charging connector of a charging apparatus in accordance with the present invention;

- Figure 5 is a schematic of the power receiving side including the vehicle- mounted receiving portion of the charging apparatus of Figure 4; - Figure 6 shows the steps of charging an electric vehicle with a charging apparatus in accordance with the present invention; and

- Figures 7 and 8 show a wall-mounted source control box in accordance with the present invention.

As shown in Figure 4, a single phase utility AC power supply is input to a wall-mounted manually operated isolator 2. When the isolator 2 is closed, the AC power inputs an AC/DC/AC inverter 4 which converts the mains AC power from 1 10/240V, 50/60 Hz to DC to a high frequency AC power at around 65 kHz. The inverter 4 is housed in a source control box 6.

A charging connector 8 is connected by an electrical cable 10 to the inverter 4. The charging connector 8 comprises a reinforced polymer casing having a substantially cylindrical and elongate charging portion 12 at one end and a handle portion 14 at the other end. The charging connector 8 sealably contains a primary electromagnetic induction coil (not shown) to which the cable is electrically connected.

As shown in Figure 5, a tubular receiving portion 16 is mounted on a vehicle (not shown). The receiving portion 16 is mounted behind the fuel filler flap of the vehicle by suitable fixing means. The receiving portion 16 is complementarily shaped to receive the charging portion 12 of the charging connector 8. The receiving portion 16 includes a secondary electromagnetic induction coil (not shown) which is electrically connected to an AC/DC inverter 20 mounted in the vehicle. The receiving portion 16 also comprises a reinforced polymer casing to sealably isolate the secondary coil from a user and prevent the ingress of dirt or water.

Desirably, the filler flap acts as a closure to the receiving portion 16 when the apparatus is not in use and prevents access to the receiving portion 16 and dirt/water ingress. When the charging portion 12 of the charging connector 8 is inserted into the receiving portion 16, power is automatically transmitted from the primary coil to the secondary coil by high frequency electromagnetic induction. The inverter 20 inverts the high frequency AC power to controlled DC power for suitable power storage means 22, such as a batteries or capacitors, mounted in the vehicle. A suitable storage means would be a 350V, 26.4 kWhr battery, for example. The apparatus includes onboard monitoring means 24 which is adapted to monitor the charging state of the battery 22. When the battery 22 is fully charged, control means 26 automatically stop power being sent to the battery 22. A switch 26 is provided between the receiving portion 16 and the inverter 20 and the control means 26 activates the switch 28 to disconnect the receiving portion 16 from the inverter 20 when the storage means is fully charged. This automatic monitoring eliminates the requirement of user interaction whilst charging the vehicle and provides for a safer and more efficient charging apparatus. The control means 26 is also adapted to determine if the vehicle is a fuel cell-only vehicle or a hybrid-electric vehicle and is adapted to select a charging regime suitable for that type of vehicle and controls the inverter 20 accordingly. The control means 26 is further adapted to detect when the charging portion 12 is fully inserted into the receiving portion 16. The charging portion 12 includes a primary capacitor-based tuned circuit (not shown) and the receiving portion 16 includes a secondary capacitor-based tuned circuit (not shown) correspondingly tuned with the primary capacitor-based tuned circuit. The primary capacitor-based tuned circuit is provided at or near a free end of the cylindrical charging portion 12 and the secondary capacitor-based tuned circuit is provided at or near the base of the tubular receiving portion 16. When the charging portion 12 is fully inserted into the receiving portion 16 the control means 26 detects this arrangement via the capacitor-based tuned circuitry and allows electric power transmission from the primary coil to the secondary coil for charging of the vehicle battery 22.

The control means 26 is adapted to automatically allow charging only when the charging portion 12 is fully inserted into the receiving portion 16 and automatically stops charging when the charging portion 12 is not fully inserted into the receiving portion 16 or when the charging portion 12 is accidentally moved from a fully engaged position. This desirably eliminates the risk to a user where the charging portion 12 is pulled in the receiving portion 16 by a person tripping over the electrical cable 10 between the charging connector 8 and the source control box 6, for example. The risk of a user not fully inserting the charging portion 12 into the receiving portion 16 and affecting relatively slow and inefficient charging is also eliminated.

The control means 26 is also adapted to test the onboard circuitry for continuity and earth fault or short circuit conditions. In the event of a fault being detected, a fault indicator may be displayed to a user, such as a fault display on the vehicle dashboard. The charging portion 12 and receiving portion 16 may comprise communication means to allow data transfer from the vehicle to suitable data storage means remotely located from the vehicle. Such data may be used for diagnostic purposes and the communication means may utilise Bluetooth™ technology, for example. The onboard part of the apparatus also includes a Controller-area network (CAN or CAN-bus) to allow microcontrollers and devices, such as the monitoring means and control means, to communicate with each other within the vehicle.

The manual and automatic steps of charging an electric vehicle using a charging apparatus as described above are shown in Figure 6. The filler flap is opened to expose the receiving portion 16. The charging portion 12 of the charging connector 8 is fully inserted into the receiving portion 16. As soon as the charging portion 12 is inserted into the receiving portion 16, the control means 26 transfers data via the Bluetooth™ connection, performs a diagnostic check for fault in the charging apparatus and detects if the charging portion 12 is fully inserted into the receiving portion 16. If so, the control means 26 closes switch 28 and allows charging of battery 22 to begin. If the charging portion 12 is knocked out of full engagement with the receiving portion 16, the control means 26

automatically stops charging by opening switch 28.

The monitoring means 24 determines the charging level of the battery 22 and adjusts the charging accordingly. When the battery 22 is full, charging is automatically stopped by opening switch 28. An audible/visual means alerts the user that the battery is full and charging is complete. The user removes the charging portion 12 from the receiving portion 16 and the vehicle is then ready for use.

As shown in Figures 7 and 8, the source control box 6 includes a holster 30 for the charging connector 8 to mount when the apparatus is not in use. The source control box 6 may include audible/visual means to indicate when the apparatus is ready for use and/or when the battery is fully charged. A commercial embodiment of the source box may comprise payment means such as a credit card reader 32 and an alpha numerical keypad 34. The control box 6 may further include visual and/or audible means, such as one or more LED's or buzzers, to indicate to a user when the apparatus is powered on and/or when the power storage means is fully charged. Such visual/audible means may also alert to a user when the charging portion 12 of the charging connector 8 is not fully inserted into the receiving portion 16 or has been knocked therefrom.

The apparatus is fully automatic in operation and is a totally isolated design. There is no exposure to live terminals or the danger of live trailing cable and a user can safely operate the apparatus in the presence of sand, dirt, ice, oil, snow or water. The charging apparatus is suitable for charging a range of battery sizes requiring different charging regimes and thereby allows for safe and efficient charging of different domestic and commercial electric vehicles.

Claims

A charging apparatus for an electric vehicle having power storage means, comprising:

- an electrical power source provided remotely from the vehicle;

- a complementarily shaped tubular receiving portion mounted on the vehicle and adapted to receive the charging portion and comprising a secondary coil so that when the charging portion is fully inserted in the receiving portion, the primary coil and secondary coil are electromagnetically coupled together to transmit electric power from the primary coil to the secondary coil by electromagnetic induction to charge the storage means of the electric vehicle;

- control means adapted to detect when the charging portion is fully inserted in the receiving portion and only allow transmission of electric power from the primary coil to the secondary coil based on said detection; and

2. An apparatus according to claim 1 , wherein the charging portion is a slightly curved cylindrical charging portion which is similar in appearance to the nozzle of a conventional petrol or diesel fuel pump.

An apparatus according to claim 1 or 2, wherein the receiving portion is adapted to enable retro-fitting to the vehicle.

An apparatus according to claim 3, wherein the receiving portion mountable behind an existing fuel filler flap.

5. An apparatus according to any preceding claim, wherein the power transfer rating of the apparatus is from 1 kW to 15kW.

6. An apparatus according to claim 5, wherein the power transfer rating is from 3kW to 10kW.

7. An apparatus according to any preceding claim, wherein the electric power transmitted from the primary coil to the secondary coil by electromagnetic induction to charge the storage means of the electric vehicle is a high frequency AC power.

8. An apparatus according to claim 7, wherein the high frequency AC power is greater than 20kHz.

9. An apparatus according to claim 8, wherein the high frequency AC power is around 65 kHz.

10. An apparatus according to claim 8 or 9, wherein the apparatus

comprises a first inverter remote from the vehicle to invert an input AC power from the power source to a high frequency AC power for power transmission from the primary coil to the secondary coil.

1 1 . An apparatus according to claim 10, wherein the input AC power is a single phase AC mains utility supply of 1 10/240V, 50/60 Hz.

12. An apparatus according to claim 10 or 1 1 , wherein the first inverter is an AC/DC/AC inverter.

13. An apparatus according to any of claims 10 to 12, wherein the

charging apparatus comprises a second inverter to invert the high frequency AC power to a DC power output suitable for the power storage means.

14. An apparatus according to claim 13, wherein the DC power output is controlled.

15. An apparatus according to claim 13 or 14, wherein the second

inverter is provided in the vehicle.

16. An apparatus according to any preceding claim, wherein the power rating of the power storage means is from 330 to 450V.

17. An apparatus according to any preceding claim, wherein the power storage means comprises a plurality of capacitors.

18. An apparatus according to any preceding claim, wherein the control means comprises a capacitor-based tuned circuit for detecting when the charging portion is fully inserted in the receiving portion.

19. An apparatus according to claim 18, wherein the charging portion comprises a primary capacitor-based tuned circuit and the receiving portion comprises a secondary capacitor-based tuned circuit correspondingly tuned with the primary capacitor-based tuned circuit.

20. An apparatus according to any preceding claim, wherein the control means is adapted to monitor the charging state of the power storage means and adapted to automatically stop charging when the storage means is fully charged.

21 . An apparatus according to any preceding claim, wherein the control means is adapted to determine if the vehicle is a fuel cell-only vehicle or a hybrid-electric vehicle and select a charging regime suitable for that type of vehicle.

22. An apparatus according to any preceding claim, wherein the control means is adapted to test onboard circuitry for continuity and earth fault or short circuit conditions.

An apparatus according to any preceding claim, wherein the charging connector and the receiving portion each comprise a housing made from a reinforced polymer material to sealably contain the respective primary and secondary coils.

A method of charging an electric vehicle using an apparatus according to any one of claims 1 to 23, the method comprising the steps of:

- inserting the elongate tubular charging portion of the charging connector into the complementarily shaped receiving portion;

- detecting full engagement of the charging portion in the

receiving portion;

- determining and selecting a charging regime for the power storage means of the vehicle from a plurality of charging regimes; - activating power transfer from the primary coil to the secondary coil and to the power storage means;

- monitoring the power level of the power storage means; and

- automatically deactivating power transfer when the power storage means is fully charged.

A method according to claim 24 further comprising one or more of the following steps:

- transferring data to/from the vehicle via communication means; and

- performing a diagnostic check for faults in the charging apparatus.