GB2573600A

GB2573600A - Re-charging electric vehicles

Info

Publication number: GB2573600A
Application number: GB1902301.9A
Authority: GB
Inventors: Peter Boxwell Michael; Peter Martin Timothy; Ratcliffe Ashley
Original assignee: Zapinamo Ltd
Current assignee: Zapinamo Ltd
Priority date: 2018-02-22
Filing date: 2019-02-20
Publication date: 2019-11-13
Also published as: GB2572676A; GB2573600A8; GB201901623D0; GB201802919D0; GB201902301D0

Abstract

An apparatus for recharging an electric vehicle (EV) has: an input device 501, a rectifier 504, a battery 503, an output device 505; and a processor 507. The input device receives electricity from a grid supply and is primarily intended for supplying electricity to a primary consumption facility 502 (e.g. streetlight). The rectifier receives alternating current from the input device and supplies direct current to the battery. The output device recharges an EV by transferring current from the battery to the EV. The processor controls the input device to: prioritise electric current requirements for the primary consumption facility; and make any remaining current from the grid supply available for charging the battery. The grid supply may include a peak and off-peak supply, wherein charging of the battery from the off-peak supply is prioritised. The output device may recharge the EV at a higher rate than the battery is charged. The recharging current from the output device may include current from the grid supply and current from the battery or the grid supply may be isolated from the battery while the EV is recharged from the battery. The primary consumption unit may include domestic equipment installed within a domestic residence, with the apparatus situated proximal to the residence (e.g. in a garage).

Description

The present invention relates to an apparatus for recharging electric vehicles. The present invention also relates to a method of recharging electric vehicles.

It is known to provide an intermediate storage capability for users of electric vehicles, as described in GB 2533176B and 2536147B, assigned to the present applicant. Devices of this type generally receive charge from a grid supply and are then transported to the location of a parked electric vehicle.

In addition to this transportable application, the applicant has also appreciated that a demand exists for substantially permanent charging facilities with local battery storage. In this way, a fixed battery can be charged from a grid supply and then used to recharge electric vehicles, possibly at a higher rate of charge. However, this assumes that a suitable grid supply is available and problems may exist in terms of having a new supply installed.

According to a first aspect of the present invention, there is provided an apparatus for re-charging electric vehicles, as set out in claim 1.

According to a second aspect of the present invention, there is provided a method of re-charging electric vehicles, as set out in claim 11.

Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 shows an apparatus for recharging electric vehicles;

Figure 2 illustrates processes performed by the processor identified in Figure 1;

Figure 3 details processes performed in response to the charge request identified in Figure 2;

Figure 4 details procedures for responding to the battery monitoring process identified in Figure 2;

Figure 5 shows an alternative embodiment;

Figure 6 shows a second alternative embodiment;

Figure 7 illustrates an embodiment of the invention positioned on a highway;

Figure 8 illustrates an embodiment for positioning within a garage;

Figure 9 illustrates the deployment of the apparatus identified in Figure 8; and

Figure 10 details operations performed by a processor identified in Figure 9.

Figure 1

An apparatus for recharging electric vehicles is shown in Figure 1 and includes an input device 101 for receiving electricity from a grid supply. However, the grid supply is primarily intended for supplying electricity to a primary consumption facility 102. The apparatus includes a battery 103 and a rectifier 104 arranged to receive alternating current from the input device 101 and to supply direct current to the battery 103, in order to perform a charging operation.

In addition, an output device 105 is provided for recharging an electric vehicle, via a vehicle connector 106, by transferring current from the battery 103. A processor 107 receives input data from a sensor 108 indicating the amount of energy being consumed by the primary consumption faciality 102. The processor 107 is preprogramed with data identifying the total amount of energy that may be taken from the grid supply. The processor 107 is configured to prioritize the electric current requirements of the primary consumption facility and then use any remaining current available from the grid supply for charging the battery.

In an embodiment, the output device 105 supplies recharging current to an electric vehicle at a higher rate than that at which the input device 101 supplies charging current to the battery. In this way, a relatively modest supply from the grid can be deployed to provide a rapid recharging faciality to an electric vehicle, effectively by charging the battery 103 at a relatively low rate while discharging the battery (and recharging an electric vehicle) at a relatively high rate.

In operation, the recharging procedure is initially performed by connecting the vehicle connector 106 to an electric vehicle, thereby effectively connecting the electric vehicle to the output device 105. The electric vehicle is then recharged by supplying recharging current from the battery 103 via the output device 105. At the end of this recharging process, the connector 106 is disconnected from the electric vehicle, which then becomes available for the next vehicle to be recharged.

The battery 103 is itself charged from a grid supply via the input device 101 and the rectifier 104. However, the processor 107 is configured such that electric current requirements from the grid supply for the primary consumption facility 102 are prioritized and only remaining current, after accounting for these requirements, is used to charge the battery 103.

Figure 2

In an embodiment, the battery 103 includes lithium titanite cells that are capable of discharging at relatively high rates and allow many charging and discharging cycles to be performed before experiencing significant degradation. However, alternative battery technologies may be deployed in alternative embodiments and in some embodiments, it is possible for recycled batteries to be used. Furthermore, it is possible for lithium titanite batteries to be used in combination with recycled batteries, as disclosed in GB 2532813B, assigned to the present applicant.

It is also appreciated that sophisticated techniques are required to maintain the integrity of the battery and, as such, the charging procedures are carefully controlled. Fortunately, technology of this type is readily available and known to those skilled in the art, given that is has been developed for the recharging of electric vehicles. Thus, from a power management perspective, the charging of the battery 103 in the apparatus is substantially similar to the recharging of a battery contained within a vehicle. Thus, as is known in the art, a degree of handshaking occurs between battery management systems and the charging and discharging procedures are carefully controlled, to avoid damaging the batteries and possibly entering dangerous current transfer regimes. The processor 104 is therefore in a position to call upon this available technology, to ensure that when a charging or recharging operation is instructed, appropriate measures are evoked in order to comply with appropriate battery management requirements.

In an embodiment, procedures executed by the processor 107 respond to interrupts. In particular, a high priority interrupt is generated when a recharging operation is required and a lower level interrupt is generated when battery charging is required. In an embodiment, a battery monitoring procedure 202 is provided that monitors the state of the battery 103 and makes an assessment as to whether a charging operation is required. Thus, in response to making this assessment, an interrupt is generated at step 202, which results in the processor 107 performing the procedures described with reference to Figure 4.

Similarly, a recharge request procedure 203 monitors requests for recharging operations and when identified, a high priority interrupt is generated by a second interrupt procedure 204. In response to a high priority interrupt being generated, appropriate procedures are conducted by the processor 107, as described with reference to Figure 3. Thus, while servicing a low priority interrupt, resulting in the battery being charged, the procedure can be interrupted by a high priority interrupt, thereby initiating procedures to facilitate the recharging of a vehicle.

Figure 3

Procedures for servicing a high priority interrupt are illustrated in Figure

3. At step 301, the high priority interrupt is captured, in response to the vehicle connector 106 being inserted within an appropriate socket of a vehicle that is to be recharged. Thereafter, in accordance with established protocols, the apparatus communicates with the vehicle at step 302 to determine an appropriate recharging schedule.

At step 303, a recharging schedule is prepared and at step 304 the apparatus is switched into its recharge mode.

At step 305 the recharging schedule is conducted and at step 306 a question is asked at to whether the recharging procedure has been completed. When answered in the negative, recharging continues, in accordance with the schedule, at step 305, until the recharging operation has been completed and the question asked at step 306 is answered in the affirmative. Thereafter, the recharging procedure stops and the apparatus is returned to its charge mode at step 307.

Figure 4

As used herein, transferring current to the battery 103 is referred to as “charging” and transferring current from the battery 103, to the internal battery of a vehicle, is referred to as “recharging”. A vehicle battery is therefore recharged and the battery 103 of the apparatus is charged; and then discharged, during the recharging procedures described with reference to Figure 3.

The charging procedures of an embodiment are illustrated in Figure 4. During some periods, the battery 103 may be fully charged and further charging will not be required. However, the battery will continue to be monitored and if its state of charge falls below a predetermined level, the recharging procedure 204 will issue a low priority interrupt which is captured at step 401. Thereafter, at step 402, a question is asked as to whether the battery requires charge. As illustrated in Figure 4, the question at step 402 is also asked upon returning from the procedure described with respect to Figure

3. Thus, after completing a recharging operation, it may be assumed that battery charging is now required to replenish the battery. Should this not be the case, the question asked at step 402 is answered in the negative and the processor is then placed in a sleep mode at step 407.

In response to the question at step 402 being answered in the affirmative, the apparatus switches to its charge mode at step 403. Appropriate switching is performed, possibly in accordance with the procedures described with reference to Figure 5 or in accordance with the procedures described with respect to Figure 6. Thereafter, a question is asked at step 405 as to whether spare power is available.

The processor 407 is aware of the amount of power that may be taken from the grid supply and as such controls the operation of the input device 101.

The input device 101 ensures that the primary consumption faciality 102 always has power available when required. The primary consumption faciality may take many forms and specific examples are described with reference to Figure 7 and Figure 8. Thus, the senor 108 determines the amount of power being taken by the primary consumption faciality 102 and from this identifies the remaining level of power that may be used to charge the battery 103. Thus, if the question asked at step 405 is answered in the negative, to the effect that no spare power is available, the processor again enters its sleep state at step 407. However, if power is available, no matter how little, the question asked at step 405 is answered in the affirmative and battery charging is performed at step 406.

In an embodiment, further procedures are conducted to periodically check the amount of spare power and, when possible, allow a higher rate of charging to occur. Furthermore, sophisticated embodiments may also include a schedule detailing specific times of day when charging is preferred. Similarly, additional constraints may be placed on the charging procedures by the grid utility.

Figure 5

An alternative embodiment is illustrated in Figure 5. Components of the embodiment shown in Figure 5 that are similar to those shown in Figure 1 are identified with corresponding reference numerals incremented by four hundred.

In the embodiment of Figure 5, recharging current from the output device 505 is derived from current received from the input device and current received from the battery.

Upon switching to charge mode at step 403, a first switch 511 is closed and a second switch 512 is opened, as illustrated in Figure 5. In this way, rectified current from the rectifier 504 is supplied to the output device 505. Thus, the output device 505 receives current from the battery 503 and from the grid supply and combines these to provide recharging current to the vehicle connector 506. When it is possible to perform this dual-source approach, it can be seen that all available power is being used to recharge a vehicle, thereby minimizing the time taken to perform a recharging operation.

Figure 6

In some environments, it is not possible to connect a recharging vehicle directly to a grid supply. A second alternative embodiment is therefore illustrated in Figure 6. Components similar to those described with reference to Figure 5 are illustrated with references incremented by one hundred. In particular, the processor 607 is configured to isolate the input device 601 from the output device 605. In this way, a direct connection from the grid supply to a recharging electric vehicle is never permitted. However, charging times are increased, compared to the procedure described with Figure 5, because recharging current from the output device 605 is only received from the battery

503.

Upon switching to the recharge mode 304, a third switch 613 and a fourth switch 614 are operated to the configurations illustrated in Figure 6. Switch 613 is ganged with switch 614, as illustrated by a ganging mechanism 615. Thus, at any instant, it is only possible for the third switch 613 or the fourth switch 614 to be connected in circuit. Thus, in this way, the battery 603 is either connected to the rectifier 604 or the battery is connected to the output device 605.

When the third switch 613 is closed, charging current is received from the rectifier 604 and the battery 603 is effectively connected to the grid supply. Alternately, when the fourth switch 614 is closed, the battery 603 supplies recharging current to the vehicle connector 606 and the rectifier 604 is completely isolated; such that power from the grid supply cannot be used to directly recharge a vehicle.

Figure 7

As shown in Figure 7, the apparatus may be situated on a highway and the primary consumption unit may also be situated on the highway. In the example shown in Figure 7, the primary consumption unit is a streetlight but it should be appreciated that other devices provided in similar locations may also constitute the primary consumption unit.

Street parking locations, such as a first street parking location 701, are provided at the side of a kerb, in close proximity to a charging station 702. The street charging station 702 includes a first battery module 703, a second battery module 704 and a third battery module 705, along with a recharging interface 706.

Figure 8

As illustrated in Figure 8, a permanently based charging hub 801 may be installed at a domestic residence. The charging hub 801 may, for example, be located at the back of a user’s garage and designed to optimize use of the space available. Thus, prior to use, a user would be encouraged to drive up to the charging hub 801 in the direction of arrow 802. A conventional rapidcharging cable then connects the vehicle to a rapid-charging socket 803.

In an embodiment, the framework of the charging hub 801 is hollow, including a hollow base 804. In this way, storage batteries and much of the required electronics may be retained within the charging hub 801, thereby making the apparatus substantially self-contained.

Figure 9

In this example, the domestic residence 201 receives a peak-rate supply 901 and an off-peak supply 902 of mains electricity. These are connected to a respective peak meter 903 and an off-peak meter 904. The domestic residence receives peak electricity via a peak distribution box 905 and off-peak electricity via an off-peak box 906.

In an embodiment, a first allocation circuit 907 is located between the peak meter 903 and the peak distribution box 905. Similarly, a second allocation circuit 908 is located between the off-peak meter 904 and the offpeak box 906. The allocation circuits 907/908 are configured to prioritize electric current requirements for domestic use. However, any power that remains available after the domestic use has been satisfied, is made available to a charge-control processor 909.

A data link 910 provides bidirectional data communication between the charge-control processor 909 and the charging hub 401. Thus, when the charging hub 801 requires energy and the charge-control processor 909 is in a position to provide energy, charging current is supplied to the charging hub 401 via a charging cable 911.

Thus, an embodiment of the present invention provides an apparatus for charging an electric vehicle, via the rapid-charging socket 403. The charging hub 401 includes a battery, possibly configured from a significant number of individual cells connected in series and in parallel. The chargecontrol processor 909 includes a rectifier for receiving alternating current from the domestic grid supply, via a peak-supply line 912 and an off-peak line 913.

Figure 10

As described with reference to Figure 9, the charge-control processor 909 receives current from the peak-supply line 912 and the off-peak line 913. Current is supplied to the battery, within the charging hub 801, and is received from this battery via the recharging cable 911. The charge-control processor 909 includes an isolation relay 1001 that includes a charge switch 1002 and a discharge switch 1003. The isolation relay 1001 ensures that the charge switch and the discharge switch may be positioned in the lower orientation, as shown in Figure 10, during which it is possible for the battery only to receive current. Similarly, when both switches are placed in an upper orientation, it is only possible for the battery to supply current, for recharging purposes.

A peak rectifier 1004 and an off-peak rectifier 1005 supply rectified current to a charge-conditioning circuit 1006 via a selection switch 1007. Thus, it is only possible for the charge-conditioning circuit 1006 to receive peak electricity or off-peak electricity but never both.

A first discharge conditioning circuit 1008 receives power from the peak rectifier 1004. Similarly, a second discharge conditioning circuit 1009 receives off peak power from the off-peak rectifier 1005. A third discharge conditioning circuit 1010 receives electrical power from the battery, via the recharge switch 1002. This power is also made available to a fourth discharge conditioning circuit 1011 and a fifth discharge conditioning circuit 1012. The fourth discharge conditioning circuit 1011 also receives power from the off-peak rectifier 1005. Similarly, the fifth discharge conditioning circuit 1012 also receives power from the peak rectifier 1004.

When charging a vehicle, the isolation relay 1001 is operated to the alternative configuration, with the charge switch 1002 and the discharge switch 1003 placed in the upper orientation. A source of energy is then selected from a charge selector 1013. In this way, under program control, the charge selector 1013 supplies recharging current for a vehicle via the rapid charging socket 403. Thus, this charging current may be derived exclusively from the peak supply via the first discharge conditioning circuit 1008. Alternatively, the charging current may be derived exclusively from the off-peak supply via the second discharge conditioning circuit 1008.

In some circumstances, it may be preferable to discharge the battery, which may form part of an overall battery maintenance routine. Thus, when charging current of this type is required, it is derived exclusively from the battery via the third discharge conditioning circuit 1010.

At other times, power may be available from the battery and from a mains supply. When off-peak electricity is available and energy is also available for the battery, charging current may be derived from the fourth discharge conditioning circuit 1011. Similarly, when peak power is available in addition to that available from the battery, charging current may be derived from the fifth discharge-conditioning circuit 1012.

Claims

1. An apparatus for recharging electric vehicles, comprising:

an input device for receiving electricity from a grid supply, wherein said grid supply is primarily intended for supplying electricity to a primary consumption facility;

a battery;

a rectifier arranged to receive alternating current from said input device and to supply direct current to said battery;

an output device for recharging an electric vehicle by transferring current from said battery to said electric vehicle; and a processor, wherein said processor is configured to control said input device so as to:

prioritize electric current requirements for said primary consumption facility; and make available any remaining current from said grid supply for charging said battery.

2. The apparatus of claim 1, wherein said output device supplies recharging current to an electric vehicle at a higher rate than said input device supplies charging current to said battery.

3. The apparatus of claim 1 or claim 2, wherein said re-charging current from said output device is derived from current received from said input device and current received from said battery.

4. The apparatus of claim 1 or claim 2, wherein said processing device is also configured to isolate said input device from said output device, such that:

a direct connection from said grid supply to a re charging electric vehicle is never permitted; and recharging current from said output device is only received from said battery.

5. The apparatus of any of claims 1 to 4, wherein:

the apparatus is situated on a highway; and said primary consumption unit is also situated on said highway.

6. The apparatus of claim 5, wherein said primary consumption unit is a streetlight.

7. The apparatus of any of claims 1 to 4, wherein:

said primary consumption unit comprises a plurality of domestic equipment installed within a domestic residence; and the apparatus is situated in proximity to said domestic residence.

8. The apparatus of claim 7, wherein the apparatus is situated in a garage.

9. The apparatus of claim 7 or claim 8, wherein said grid supply includes a peak supply and an off-peak supply.

10. The apparatus of claim 9, wherein said processor is configured to prioritize the charging of said battery from said off-peak supply.

11. A method of recharging electric vehicles, comprising the steps of: connecting an electric vehicle to an output device;

recharging said electric vehicle by supplying charging current from a battery via said output device;

disconnecting said electric vehicle from said output device after being recharged; and charging said battery from a grid supply via an input device, wherein: electric current requirements of said grid supply for a primary consumption facility are prioritized; and only remaining current, after accounting for said requirements, is used 5 to charge said battery.

12. The method of claim 11, wherein said recharging step is performed at a higher power than said charging step.

10

13. The method of claim 11 or claim 12, further comprising the step of receiving recharging energy directly from said grid supply in addition to receiving recharging energy from said battery.

14. The method of claim 11 or claim 12, further comprising the step 15 of isolating said grid supply from said battery while recharging a vehicle from said battery.

15. The method of any of claims 11 to 14, wherein said grid supply includes a peak supply and an off-peak supply.