GB2617169A

GB2617169A - Improved interface and vehicle

Info

Publication number: GB2617169A
Application number: GB2204667.6A
Authority: GB
Inventors: Drew Nick
Original assignee: Switch Mobility Ltd
Current assignee: Switch Mobility Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2023-10-04
Anticipated expiration: 2042-03-31
Also published as: GB202204667D0; GB2617169B

Abstract

An interface for charging a battery pack B of an electric vehicle 20, the interface being connectable to a power source for charging the battery. The interface having a plurality of ports P, including a first and second port, each having a terminal connected to each other, for detecting the attachment of a power source. The terminals may have a measurable impedance having a first value when there is no connection thereto, and a second value when the/or each socket is connected to a power source attachment. The impedance may be defined by a resistor connecting the terminal to an earth terminal, or by each terminal arranged in a parallel. The interface may have a third port. The first value may be static, and the second value may be a resultant impedance of the interface when a power source attachment is connected to one of the ports. The difference in resultant impedance between an interface having a single connection and a plurality of connections may be between up to 20%. There may be a four-sided vehicle having the interface, where the first and second ports are positioned on different or opposite sides of the vehicle. The vehicle may have a switching unit S, charging unit C, and battery pack. The ports may have open and closable covers.

Description

IMPROVED INTERFACE AND VEHICLE

The invention relates to an interface, and a vehicle having such an interface. More specifically, the invention relates to an automotive vehicle having battery packs and powered, at least in part via an electric motor, and the interface for connecting a power source to recharge the batteries.

BACKGROUND

Known electric vehicles are rechargeable by or from power sources e.g. an Electric Vehicle Supply Equipment (EVSE) and must comply with various standards. Standards that relate to plugs, socket-outlets, vehicle connectors and vehicle inlets include IEC 62196, ISO 17409 or ISO 18246.

Similar requirements are contained in SAE J1772. The standards include specific requirements for additional contacts or functions that support specific functions that are relevant for charging of electric vehicles, e.g. power is not supplied unless a vehicle is connected and the vehicle is immobilized while still connected. For example, the standards include specifications that determine the layout of plugs and sockets, including the terminals, such as the live (L 1, L2, L3, DC-mid), neutral (N) and protective earth (PE) connections, as well as pre-insertion signalling (PP -proximity pilot, also referred to as plug-present') and post-insertion signalling (CP -control pilot).

EVSEs can be expensive to install and tend to be in fixed positions. When fixed, an EVSE should be within reach of a vehicles charging connection point, thus keeping the cable short. In some circumstances, positioning a vehicle with an EVSE results in the vehicle's single charging connection point being far from the EVSE e.g. on the opposite side of the vehicle. Positioning can be particularly problematic if the vehicle is long and/or high e.g. a bus or a coach, and there is insufficient room for manoeuvring the vehicle to align the EVSE with single charging connection point. Providing a longer cable that permits connection to the EVSE by reaching around or over the vehicle results in a cable that is more expensive, difficult to handle and more susceptible to damage.

Examples of the disclosure provide solutions to at least these technical problems.

SUMMARY

The invention generally relates to vehicles, and in particular electric vehicles having two or more charging ports for charging a battery pack of the vehicle. The ports can be positioned on opposite sides of the vehicle to optimise accessibility and/or connectability with an EVSE. This is especially relevant when an EVSE has a fixed location with restricted access and/or the vehicles are large and positioning in relation to the EVSE is limited e.g a 12m or 18m long bus within a depot. Safety standards must be met while implementing two or more ports, which can be achieved without significant increase in cost and/or complexity in light of the examples herein.

In a first aspect, there is provided an interface for charging a battery pack of an electric vehicle, wherein the interface is connectable to a power source for charging the battery back. The interface comprises a plurality of ports, including a first port and a second port. Each port has a terminal for detecting the presence or non-presence of a power source attachment. The terminal of the first port and the terminal of the second port are connected. By providing a single interface, with connected ports, the cost and/or complexity can be reduced. The power source can be an EVSE. The power source attachment can be a plug. The port can be a socket.

Each terminal can have a measurable impedance. Measurement can be achieved using a switch and/or charger connected thereto can be connected to the terminal and measure the impedance. The impedance can include resistor values. The measured impedance can indicate the status of a connection to a port. A first impedance value can indicate that there is no connection to a port. A second impedance value can indicate that the or each socket is connected to a power source attachment. In each port, a resistor can be connected between across the terminal, wherein the terminal comprises the proximity-pilot (PP) wire and the protective-earth (PE) wire of the port The resistor IS can be connected across the PP and PE connections in the terminal block of the port.

The power source attachment can be a connector of a charging station e.g. an EVSE. At least one of the plurality of ports can be a socket configured to connect with a power source attachment. The power source attachment can be a plug. A port and an EVSE can be connected i.e. removably connected. Each terminal can have a measurable impedance defined, at least in part, by a resistor connecting the terminal to an earth terminal. The terminal can be a proximity pilot terminal e.g. a plug-present terminal. The measurable impedance of each terminal can be defined, at least in part, by the impedance of each terminal arranged in a parallel.

The interface can have a third port. The port can have a cover. The cover can define a surface or the vehicle. The or each port can have a separate cover. A plurality of ports can allow for positioning of charging ports at accessible points around the perimeter of a vehicle The first impedance value of each terminal can be is static. The resistor within the port can have a fixed nominal value. The second impedance value is a resultant impedance of the interface when a power source attachment is connected to one of the plurality of ports. By having static e.g. fixed impedance values and/or resistance values the cost of the ports and/or the vehicle charging system can be kept low cost. Overall, compared to a vehicle having a single charging port, the difference in resultant impedance using the teaching herein can result in differences up to 20%, and preferably up to 10%, and preferably up to 0.5%. Lower differences e.g. under 0.5% can be achieved if an interface has an impedance value set by the number of ports e.g. there are N different impedance values, which is the same for each port, when there are N ports.

Differences of up to 10% can be accommodated by vehicle charging systems having a single impedance value for each port when the interface has between 2 and 4 ports. Differences of up to 20% can be accommodated by vehicle charging systems having a single impedance value for each port when the interface has between 2 and 6 ports. Differences of up to 10% and up to 20% can still be accommodated by vehicle charging systems and, therefore, a fixed impedance values and/or resistance values that are independent of the number of ports can be used to further reduce the cost and complexity of the interface. The same values of fixed impedance values and/or resistance can be used for each port for interfaces having between 2 and 6 ports.

In another aspect, there is provided a vehicle having an interface as claimed herein. The vehicle has at least four sides, including a front-side, rear-side, left-side and right-side. The first port and the second port are positioned on different sides. The first port and the second port can be positioned on opposite sides of the vehicle. In this way the vehicle can align one of the ports more easily e.g. without manoeuvring the vehicle and/or a long cable.

The vehicle can have at least one of: a switching unit, configured to selectably connect one of the plurality of ports to a charging unit; a charging unit configured to charge a battery pack when connected to a power source attachment; and a battery pack. One or more of these units or packs can be integrated.

Each port can be configured with covers. Therefore, a plurality of covers can correspond to each of the plurality of ports. The covers can be movable between a closed position and an open position. The switching unit and/or charger can detect e.g. via a microswitch or sensor on the cover when a port is in an open position and selectably connect said one of the plurality of ports for charging the battery pack.

It is to be noted that impedance and resistor values described herein refer to nominal values and the invention is not so limited and accommodates components tolerance bands.

In light of the teaching of the present invention, the skilled person would appreciate that aspects of the invention were interchangeable and transferrable between the aspects described herein, and can be combined to provide improved aspects of the invention Further aspects of the invention will be appreciated from the following description.

DESCRIPTION OF THE FIGURES

In order that the invention can be more readily understood reference is made, by way of example, to the remaining drawings, in which: Figure I a, which is a schematic diagram of a known connection between a 'charge point side' connector and vehicle side connector in which the proximity pilot (PP) and earth connections are shown connected; Figure lb is a table listing the different resistance arrangements in Figure la together with the resultant resistance; Figure 2 is a detailed schematic of the terminal block in the vehicle side connection of Figure lc, including a power cable, two control wires and a resistor; Figure 3 is a schematic representation of two vehicle ports, having their proximity pilot (PP) and earth wires connected together, and a one of the ports connected to the charge point side i.e. an Electric Vehicle Supply Equipment (EVSE); Figure 4 is a selection of tables showing the resultant resistance for a vehicle having 2, 3, 4, 5 or 6 ports, when one of the plurality of ports is connected to an EVSE, wherein the port resistance differs depending on the port count; Figure 5 is a selection of tables showing the resultant resistance for a vehicle having 2, 3, 4, 5 or 6 ports, when one of the plurality of ports is connected to an EVSE, wherein the port resistance is fixed; and Figure 6 is a schematic of a vehicle having a plurality of ports, wherein each port is connected to switch and/or a charger for recharging a battery pack. Like reference numerals refer to like features.

DETAILED DESCRIPTION

Figure la shows a charge point side e.g. EVSE 2 connector engaged with a vehicle side 4 connector. Each connector has a proximity pilot (PP) wire 6 and an earth wire 8. The connectors 2, 4 are configured to connect the PP wire 6 in the charge point side to the vehicle side, and similarly connect the earth wire 8 in the charge point side to the vehicle side. On the charge point side connector 2, a charge-resistor 10 resistor labelled '? Ohms' connects the PP wire and the earth wire -its value is labelled with '?' because the vales are determined by the aforementioned standards and different values are used to indicate the maximum current capacity, in amperes, provided by the charge point side connection, e.g. EVSE. In the examples herein, a vehicle-resistor 12 connects the PP wire and the earth wire within the vehicle and is labelled '4700 Ohms'.

A resultant resistance can be measured across/between the PP wire 6 and the earth wire 8 when the EVSE 2 connector is engaged with a vehicle side 4 connector The resultant resistance detects the parallel arrangement of the charge-resistor 10 and the vehicle-resistor 12. Figure lb tabulates a measurable resultant resistance when the charge resistor i.e. the EVSE resistance is 100ohms, 220 ohms, 680 ohms and 1500 ohms, and the vehicle-resistor 12 i.e. port resistance is fixed at 4700ohms.

A vehicle management system can monitor the resultant resistance and prevent the vehicle from being driven if the measured value is less than 4700ohms, or less than a tolerance range thereof, which indicates that a charge point side e.g. EVSE 2 connector is attached to the vehicle.

Figure 2 illustrates an example a power cable 14 of a vehicle connected to a terminal block 16.

The block, by way of example, is configured in port P on the vehicle. The port P includes a vehicle side 4 connector. By way of example, the port P can be a socket for receiving a plug connected to an EVSE 2. The power cable 14 has five wires -one for each phase (L1, L2, L3), neutral (N) and protective earth 8 (PE) -terminating in said block. The PP wire 6 and a control proximity CP wire 18 are also connected to the terminal block 16. The vehicle-resistor 12 is connected between the PP wire 6 and the earth wire 8. The power cable is illustrated by way of example as a 3-phase, neutral and earth cable although the invention is not limited thereto. The power cable P can alternatively be a single-phase cable or a DC cable.

Figure 3 illustrates a vehicle 20 having seven ports P positioned around the perimeter of the vehicle, each port connected via a power cable 14 to a charging arrangement, said charging arrangement including at least one of: a switch S that operates; a charger C that receives voltage from a port P; and a battery B pack. The switch S can be integrated with the charger C. The charger manages the incoming voltage supply from an EVSE to recharge the battery pack. The vehicle 20 can be provided with a plurality of charging arrangements and the invention is not limited to the example of Figure 3. The vehicle, as shown in plan view, has at least four sides, including a front-side 20a, rear-side 20b, left-side 20c and right-side 20d. Each of the ports P are separate yet commonly connected to define an interface that is connected to the switch S via the respective power cables 14 attached to each port 4. It is to be noted that at least two ports, e.g. a first port and a second port are positioned on different sides of the vehicle 20 e.g. on opposite sides of the vehicle.

The switch S is configured to selectably connect one of the plurality of ports P to a charger.

The switch can be part of the interface. A vehicle operator can connect a plug 2 of an EVSE into one of the ports P and the switch selectably connects based on at least one of: detecting which of the ports P have a connection from the change in resultant resistance; and detecting the opening of a cover of a port, said cover movable between an open and closed position and having a detector upon the cover than provides a signal to the switch S e.g. a microswitch in the port P detects the position of the port's cover. Via the PP terminal the resultant resistance indicates the presence or non-presence of a connection to an EVSE e.g. a plug of a charging system.

If two or more covers are opened simultaneously and/or two or more EVSE connectors are connected to vehicle ports the switch S and/or the charger C can be configured to recognise the respective resultant resistance value -in such situations the vehicle can generate a warning e.g. a warning light on the dashboard, or preventing the vehicle from being driven.

Figure 4 shows a charge point side e.g. EVSE 2 connector engaged with one of a two vehicle side 4 connectors. A bridge 22 connects the PP wire 6 of one port 4 to the PP wire 6 of the other port 4. Further ports 4 can be connected in parallel to those shown in Figure 4. Together, the ports define an interface, common to all ports because they are connected. Similarly, a bridge 22 connects the earth wires 8 of the respective ports. Each port has a terminal for detecting the presence or non-presence of a power source attachment. The terminal includes a connection to the PP wire 6 and the earth wire 8 of the port 4 -a resultant impedance can be measured across the terminal. When there is I 5 no connection to an EVSE the resultant resistance measured across the terminal has a first impedance value e.g. 4700 ohms. When an EVSE is connected to any one of the ports, the resultant resistance measured across the terminal has a second impedance. A change in impedance arises because resultant resistance measurement factors in the impedance of the other port, or ports, as well as the charge-resistor 10 (labelled '7 Ohms') within the EVSE connector 2. While the terms 'resistor' or resistance has been used to describe the components 10, 12 connecting the PP wire it is to be noted that they can be interchangeable with the term 'impedance'. In other words, each terminal has a measurable impedance defined, at least in part, by a resistor connecting the terminal to an earth terminal. Moreover, the values used in the examples herein are nominal values and do not have tolerance ranges.

The value of the impedance of the vehicle-resistor 12 of the ports P is preferably fixed or static.

Without an EVSE connected, a first resultant impedance of the terminal i.e. measured across the PP wire 6 and the earth wire 8 of the port 4, is based on the port 4 impedance. A second resultant impedance is measured when the or each socket is connected to a power source attachment and, therefore, based on the port 4 impedance and the impedance of the EVSE connector.

When a plurality of ports P are configured on a vehicle the above-mentioned standards must continue to be met. This can be achieved by configuring the port P to present a comparable resultant resistance to the switch C and/or the charger to vehicle having a single port P i.e. as shown in the table of Figure lb. The examples herein present a low cost solution for meeting the required standards.

Examples include (i) setting the vehicle-resistor 12 of the ports P according to the number of ports provided on a vehicle, (ii) setting a value of the vehicle-resistor 12 of the ports P such that the difference between the resultant resistance of a single port vehicle is within a threshold compared to the resultant resistance of a vehicle having a plurality of ports, e.g. between two and six ports, and (iii) configuring a plurality of ports on a vehicle with the same vehicle-resistor 12 value as a vehicle having a single port, wherein the switch S and/or the charger C are programmed to determine the number of ports P and recognise a range of resultant resistance values, wherein each of the values in said range correspond to either the first resultant impedance of the terminal (no EVSE connection) or the second resultant impedance is measured when a port is connected to a power source attachment.

Figure 5 is a set of five tables indicating, by way of example, different vehicle-resistor 12 i.e. port P resistance values for a vehicle having between 2 and 6 ports. For example, if the interface had a single port were to have a vehicle-resistor 12 i.e. the resistor in the port, of 4700ohms, then an interface having N ports would have a port resistance 12 value of approximately 'N x 4700'. Each table includes: the EVSE resistance; port resistance; the interface resistance, which represents the collective resistance of the ports of the vehicle, calculated by dividing the resistance at each port by the number of ports; and a percentage difference between the resultant resistance of a vehicle having a single port e.g. as shown in Figure lb and a vehicle having between 2 and 6 ports P. It can be appreciated that setting the vehicle-resistor 12 value according to the number of ports of the interface can maintain the percentage difference beneath 0.5%, and in the examples shown the maximum difference is 0.2%. It is to be noted that the port resistance value is a multiple of the port resistance when a vehicle is provided with a single port, said multiple corresponding to the number of ports e.g. if a vehicle with a single port has a port resistance of 4700ohms then a vehicle having three ports has a port resistance of 3x 4700ohms. To achieve the exact multiple of port resistance value a variable resistor can be used. In practice, and in the example tables of Figure 5, off-the-shelf resistor values closest to the multiple value have been selected.

Figure 6 is a set of five tables indicating, by way of example, a percentage difference between the resultant resistance of a vehicle having a single port e.g. as shown in Figure lb and a vehicle having a common vehicle-resistor 12 value for a vehicle having between 2 and 6 ports. It can be appreciated that setting a common value results in percentage difference lying within a threshold.

When, by way of example, a vehicle-resistance 12 is set at 14000ohms, the percentage difference is: up to 7.66%, and within 10%, when a vehicle has four ports; and up to 19.7%, and within 20%, when a vehicle has six ports.

While several embodiments of the present disclosure have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teaching of the present disclosure is/are used.

In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of' shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. Use of ordinal terms such as "first," "second," "third," etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

The invention also consists in any individual features described or implicit herein or shown or implicit in the drawings or any combination of any such features or any generalisation of any such features or combination.

Claims

CLAIMS 2. 3. I 5 5. 7.An interface for charging a battery pack of an electric vehicle, wherein the interface is connectable to a power source for charging the battery back, the interface comprising a plurality of ports, including a first port and a second port, wherein each port has a terminal for detecting the presence or non-presence of a power source attachment, and the terminal of the first port and the terminal of the second port are connected.The interface of claim 1, wherein each terminal has measurable impedance having a first impedance value when there is no connection thereto, and a second impedance value when the or each socket is connected to a power source attachment.The interface of claim 1 or 2, wherein at least one of the plurality of ports is a socket configured to connect with a power source attachment.The interface of any preceding claims, wherein each terminal has a measurable impedance defined, at least in part, by a resistor connecting the terminal to an earth terminal.The interface of any of claims 2 to 4, wherein the measurable impedance of each terminal is defined, at least in part, by the impedance of each terminal arranged in a parallel.The interface of any preceding claims, wherein the interface has a third port.The interface of any of claims 2 to 6, wherein the first impedance value of each terminal is static.The interface of any of claims 2 to 7, wherein the second impedance value is a resultant impedance of the interface when a power source attachment is connected to one of the plurality of ports.The interface of claim 9, wherein the difference in resultant impedance between an interface having a single connection and a plurality of connections is between up to 20%, and preferably up to 10%, and preferably up to 0.5%. 10. I I. 12. 13.ISA vehicle having an interface of any preceding claim, wherein the vehicle has at least four sides, including a front-side, rear-side, left-side and right-side, and wherein the first port and the second port are positioned on different sides.The vehicle of claim 10, wherein the first port and the second port are positioned on opposite sides of the vehicle.The vehicle of claim 10 or 11, further comprising at least one of: a switching unit, configured to selectably connect one of the plurality of ports to a charging unit; a charging unit configured to charge a battery pack when connected to a power source attachment; and a battery pack.The vehicle of any of claims 10 to 12, further comprising a plurality of covers corresponding to each of the plurality of ports, wherein each of said covers are movable between a closed position and an open position, and a switching unit, configured to selectably connect one of the plurality of ports to a charging unit when the port's cover is in the open position.