A device for distributing current

Abstract

A device 10 for distributing current from an electric vehicle supply equipment (EVSE) 12 to a plurality of outputs through a plurality of cables comprises: a first input, a modulator (e.g., pulse widt

Description

The present invention relates to a device for distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables and to a method of distributing current and relates particularly but not exclusively, to a device that can distribute the current from an EVSE to more than one vehicle. EVSEs are used for safely transferring electrical power from the grid to the battery of a plug-in electric vehicle. This equipment includes charging stations, connectors, cabling, and control systems that regulate power flow whilst ensuring safe and efficient charging. The EVSE equipment has two main functions. Firstly, it communicates through signals with the electric vehicle and secondly it provides power to the vehicle. Over the past two decades EVSE technology has been standardised to establish uniform protocols and connector types across different systems. This standardisation has enabled electric vehicles from various manufacturers to be compatible with a wide range of EVSE setups. One common disadvantage of EVSE is the substantial costs associated with buying the equipment and the cost of installation. Other disadvantages include the prolonged charging time especially with households having more than one electric vehicle, these households must charge vehicles sequentially when only one EVSE is available. Furthermore, compatibility issues among different EVSE types can impede integration across electric vehicle models, with differences in connector types and charging protocols becoming a continued problem. Additionally, for many households the incoming electricity supply is only sufficiently rated to allow one for EVSE installation. Preferred embodiments of the present invention seek to overcome or alleviate the above described disadvantages of the prior art. According to an aspect of the present invention there is provided a device for distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, the device comprising: a first input for receiving a first cable wherein the first cable transports a current and a first signal from the EVSE; a modulator for modulating the first signal from the EVSE thereby communicating with the EVSE a current requirement; a splitter for dividing the current into a plurality of partial currents; and a plurality of outputs for transferring the partial currents from the splitter through the second cables. By including a splitter, the device can efficiently distribute current from the EVSE to multiple outputs. This enables the device to support the charging of multiple electric vehicles simultaneously by splitting the current into partial currents . The addition of a modulator allows for bi-directional communication with the EVSE, enabling real-time adjustments to the current requirement. By integrating the modulator, the device establishes communication via the first signal that typically occurs only between the electric vehicle and the EVSE. This arrangement enables the device to "present" as a single connected vehicle to the EVSE and makes it possible to charge two vehicles simultaneously. By including the splitter and the modulator reduces the need for additional EVSE installations and lowers costs for households or facilities with more than one electric vehicle. In a preferred embodiment the splitter comprises a processor and at least one switch wherein the processor controls the switch, thereby directing the partial current to one or both of the outputs. By including a processor and at least one switch, the splitter can vary the amount of partial current directed to each output. This can further enable customised charging based on user preferences or real-time needs. Additionally, this configuration enables the splitter to respond to different power requirements of the electric vehicles and efficiently balance the distribution of current based on the charging capacity of the vehicles. The control of the processor over the switches further allows the device to adjust charging rates automatically and reduce the total charging time when one vehicle requires less power or has completed charging. Additionally, the processor can implement load-balancing algorithms to optimise power usage and potentially reduce energy costs . In another preferred embodiment the switches comprise contactors . Contactors typically work well under high voltage and high current conditions, making them a suitable device for use in high power switching circuits. Contactor control (via the processor) also ensures that the EVSE power output remains isolated until a secure connection is made with the device and electric vehicle, safeguarding against accidental power discharge. It regulates the power level delivered to the vehicle and ensures that the correct amount is supplied without risk of overcharging. Additionally, it protects the AC power source from overloading by carefully managing power distribution. In the event of an electrical fault, the contactor control enables immediate disconnection from the power source, providing an added layer of safety for both the vehicle and the device. In a further preferred embodiment, wherein the device further comprises a priority system that prioritises electric vehicles connected to the outputs according to a second input. In an additional preferred embodiment, the second input comprises a user input wherein a user sets the priority of the electric vehicles. The priority system provides flexibility for households or businesses with multiple electric vehicles and enables the device to optimise charging based on individual vehicle needs, schedules, or urgency. With the priority system, users can ensure that a specific vehicle receives a greater share of the partial current if it requires a faster charge or has a lower battery level. This reduces downtime for high-priority vehicles and allows them to be ready for use sooner. In a preferred embodiment the apparatus further comprises a rectifier for rectifying the first signal to generate a rectified signal wherein the rectified signal provides power to the device. By rectifying the first signal the circuits within the device can be powered by drawing power from the first signal. By parasitically drawing this power from the first signal, power is always available, and the device will not require a battery or a local power source. This reduces the weight of the device and therefore increases its portability and functionality. In a further preferred embodiment, the first signal comprises a control pilot signal. In another preferred embodiment the modulator comprises a pulse width modulator. In an additional preferred embodiment, the modulator comprises a switchable resistor network. In an additional preferred embodiment, the modulator comprises a controllable voltage reference source. According to an aspect of the present invention there is provided a method of distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, comprising the steps: connecting a device comprising an input, a plurality of outputs, a modulator and a splitter to an EVSE; receiving at least one signal from the EVSE through the input; modulating the at least one signal to produce a modulated signal; sending the modulated signal back to the EVSE through the input; the EVSE receiving the modulated signal and sending a current to the device; dividing the current into partial currents using the splitter; and delivering the partial currents through the outputs. In a preferred embodiment the splitter comprises a processor and at least one switch wherein the processor controls the switch, thereby directing the partial current to one or both of the outputs. In another preferred embodiment the switches comprise contactors . In a further preferred embodiment, the method further comprises the step prioritising electric vehicles connected to the outputs according to a second input. In a preferred embodiment the second input comprises a user input wherein a user sets the priority of the electric vehicles. In another preferred embodiment the method further comprises the step rectifying the first signal to generate a rectified signal wherein the rectified signal provides power to the device. In an additional preferred embodiment, the first signal comprises a control pilot signal. In a further preferred embodiment, the modulator comprises a pulse width modulator. In a preferred embodiment the modulator comprises a switchable resistor network. In another preferred embodiment the modulator comprises a controllable voltage source. Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense with reference to the accompanying drawings in which:- Figure 1 is a schematic representation of a device of the present invention used with an EVSE; Figure 2 is a perspective view of the device of figure 1; Figure 3 is a flow chart of the present invention of figure 1; and Figure 4 is a graphical representation of a communication between the device and the EVSE of figure 1. Initially referring to figures 1 and 2, a device 10 is used for distributing current from an electric vehicle supply equipment (EVSE) 12 to two electric vehicles 14 through a first cable 16 and a pair of second cables 18. The EVSE 12 will typically be installed at a residential property where it functions as a dedicated power source to supply electric current for charging one or more electric vehicles 14. The EVSE 12 receives power from the main electrical system of the house and is equipped to distribute current in a controlled manner. The EVSE has five electrical connections, a switched live, a switched neutral, a control pilot signal, a proximity pilot signal and earth. Each of these electrical connections have their own dedicated line (not shown) located within the first cable 14. The control pilot signal is a square wave that has a specific duty cycle and amplitude (as seen in figure 4) . The duty cycle indicates the level of power available from the EVSE 12, while the amplitude reflects the state of the device 10, that is, if the device is disconnected, connected, or ready to receive power. By way of electrical connectivity, via the switched live and switched neutral connection, the EVSE 12 provides power through the first cable 16 to the device 10 and finally to the electric vehicle 14. The device 10, as shown in more detail in figure 2, has a trapezoidal shape with a rectangular base 20. Extending from the base 20 is a first and a second face 22 and 24. Located centrally on the first face 22 is a circular input 26. Surrounding the input port 26 is a protective cover 28. The protective cover 28 includes a protruding handle 30 designed to allow a user to twist or grip it easily for removal. The cover 28 also includes a retaining string 32 attached to its side to secure it to the first face of the device 10, preventing it from getting lost when detached. Opposing the first face 22 is the second face 24 and includes two outputs 32 positioned side by side. Each output 32 also includes a protective cap 34. The cap 34 includes an elevated edge 36 around its circumference to assist with grip, and a hinge 38 on the opposing edge to enable removal of the cap by lifting. These protective caps 34 and cover 28 provide a secure seal over the input and outputs, 26 and 32, and protects them from dust and moisture. Additionally, secured to a third face 39 of the device 10 and the base 20 is a mounting bracket 40 and associated screws 42. This mounting bracket 40 is used to secure the device 10 to a surface such as a wall or garage floor. The mounting bracket 40 can be removed from the device 10 by extracting the screws 42 or detached from the surface it is secured to, allowing for portability. Located inside the device 10 (not shown) is a modulator, in the form of a switchable resistor network, and a splitter, implemented as a microprocessor and contactors. The modulator may also take the form of a pulse width modulator or controllable voltage source, while the splitter could alternatively be in the form of switches, relays or power semiconductors. The modulator is responsible for adjusting the first signal, in the form of a control pilot signal 44 and enables bi-directional communication with the EVSE 12. The splitter within the device 10 divides the current that is supplied by the EVSE 12 into multiple partial currents for distribution between the connected electric vehicles 14. Also located within the device 10 is a priority system, which allows the user to choose between different charging options through a second input. These charging options could include but are not limited to, choosing what vehicle they would like to charge first, choosing if the vehicles are charged simultaneously or choosing to charge one vehicle to a specified amount before switching to charge the other vehicle. Depending on what the user chooses determines how much partial current is directed through each output 32. This second input can also enable the user to choose the charging speed of one or both vehicles by varying the value of partial current supplied. In cases where only a single vehicle is connected, the splitter will direct the full input current through one of the second cables 18, ensuring that the vehicle receives the maximum available power. The priority system includes a single push button (not shown) that when pressed cycles between three options. Option 1, fully charge the first vehicle and then charge the second vehicle. Option 2, fully charge the second vehicle and then charge the first vehicle. Option 3, charge the first and second vehicle simultaneously. Feedback of which is provided to the user. The circuitry and processors within the device 10 are powered parasitically by drawing energy directly from the control pilot signal 44. This is accomplished by integrating a rectifier circuit within the device 10. The circuit rectifies, filters, and steps down the negative half of the square wave (of the control pilot signal 44) to generate a supply voltage for the device 10. The rectifier is designed to ensure that the positive half cycles of the square wave (0 to +12V), responsible for communicating with the EVSE, remains unaffected. The operation of the device 10 when connected between the EVSE 12 and the electric vehicle 14 will now be described. Referring additionally to figure 3, the connection process between the EVSE 12, the device 10, and the electric vehicles 14 begins with the user removing the protective cover 28 from the input 26 on the first face 22 of the device 10. The user removes the cover 28 by gripping the handle 30 and twisting or pulling it off. The retaining string 32 ensures the cover 28 remains attached to the device 10 and does not get misplaced. Next, the user connects the first cable 16 into the EVSE 12 and then into the input 26. At this stage a mechanical lock may trigger on the EVSE to secure the first cable 16 into place. Subsequently, the user moves to the second face 24 of the device 10, where the outputs 32 are located. The user lifts the protective caps 34 by gripping the elevated edge 36 and tilting them on the hinge 38 to expose the outputs 32. The user then connects each of the second cables 18 into the respective outputs 32 at one end and into the electric vehicle 14 at the other end (step SI in figure 3) . At this stage a mechanical lock may trigger on the electric vehicles to secure the second cables 18 into place. Once connected, the device 10 initiates a series of steps (steps S2 to S6) to establish the charging process. When the first cable 16 is connected to the EVSE a proximity signal is generated. This proximity signal informs the EVSE that a connector has been inserted into the EVSE. In a normal charging scenario, the cable is plugged into the EVSE and responds with a positive proximity signal. This is mimicked by the device and in effect the proximity signal signals to the EVSE that something (in this case an electric vehicle) is plugged in and may require charge. Next, the EVSE generates the control pilot signal 44 that is sent to the device 10 along the control pilot line (not shown) within the first cable 14. The EVSE 12 can set the magnitude of the control pilot signal to 0V, or 12V or to a 1kHz PWM waveform with magnitude of + / -12V. In step 3 (S3) the EVSE 12 communicates to the device 10 what the maximum available current is. This is achieved by the EVSE 12 modulating the duty cycle of the control pilot signal 44 through pulse width modulation (PWM). Next (S4), the device 10 monitors and modulates the received control pilot signal 44 depending on the power requirement of the electric vehicles 14 connected. It achieves this by changing the impedances in the control pilot signal 44 by using the switchable resistor network. By switching in different resistances, the device 10 modulates the control pilot signal 44 and communicates to the EVSE 12 that it is ready to receive charge. Next (S5), the EVSE 12 supplies a current (depending on the duty cycle of the control pilot signal 44), to the input 26 of the device 10 through the first cable 16. The splitter receives this current and divides it into partial currents based on the user-specified charging priorities. The microprocessor within the splitter receives the second input from the user, which decides both the charging speed and which of the vehicles is prioritised for charging. For example, the user may specify a 50% current allocation to each vehicle, direct 100% of the current to a single vehicle, or set a 75% / 25% distribution between two vehicles. Based on the second input the microprocessor controls the contactors to adjust current flow to ensure that each vehicle receives the specified partial current (S6). When charging is complete (S6), the user can disconnect the device 10 by reversing step 1 (SI). The user would first remove the second cables 18 from the electric vehicles 14 and then from the outputs 32 on the second face 24. After detaching each second cable 18, the protective caps 34 can be closed over the outputs to protect them from dust and moisture. The user would then proceed to disconnect the first cable 16 from the input 26 on the first face 22 and re-secure the protective cover 28 by aligning it with the input and twisting it into place. If the user wants to move the device 10 for able use, they could also detach it from the wall or floor by removing the screws 42 from the mounting bracket 40, or by disconnecting the brackets from the wall or floor. Referring now to figure 4, a modulated control pilot signal 44 is shown, labelled as periods T1 to T10. This figure highlights several communication procedures that can occur between the EVSE 12 and the device 10, but not necessarily in the sequence shown. In period Tl, the EVSE supplies a continuous 12V, signalling that the device 10 is not connected and that it is not prepared to deliver current / power. Upon connection of the device 10, period T2 is initiated. The control pilot signal 44 is pulled down to 9V, thus notifying the EVSE 12 that connection of the device 10 has occurred. Period T3 begins when the EVSE applies the PWM signal on the control pilot line 44, indicating it is ready to supply power at the level defined by the PWM duty cycle. As the power device 10 starts drawing power, period T4 begins, and the signal is pulled down to +6V. This level confirms that the electric vehicles 14, connected to the device 10, are drawing current. When the device 10 stops drawing current, period T5 begins, and the signal is released back to +9V, indicating that power is no longer being drawn. During periods T6 and T7 the device 10 pulls the signal down to +6V to indicate that it is taking power. During T7 the duty cycle also reduces indicating that the device has reduced the maximum current that it is drawing. If the maximum current becomes less than the rated current for the electric vehicle the device 10 will switch off. If the required current falls below the rated current, period T8 occurs, where the device 10 releases the signal back to +9V, confirming that power is no longer being drawn. When the device 10 completes charging of the connected vehicle, Period T9 is initiated, and the signal returns to +12V, enabling the EVSE 12 to release any locking mechanism. Finally, in Period T10, the system reverts to its initial state, signalling that the EVSE 12 is off and not ready to supply power, similar to Period Tl. The preceding examples are a non-exhaustive list of suitable techniques and others are available which may be selected at the discretion of the person skilled in the art. It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the protection which is defined by the appended claims. In particular, where various embodiments and aspects of the invention have been described above, features and steps of the apparatus and method are interchangeable between the embodiments and aspects of the invention. For example, where dimensions are indicated in the examples set out above these are examples of ideal measurements but should not be taken as being indicative of being essential to the performance of the invention. For example, the device as described above can connect to either one or two electric vehicles. However, more than two outputs could be included on the device, enabling more than two electric vehicles to be connected. A further example, while the device includes self-powering capabilities, it can also be powered 5 through the use of batteries or a direct power line connection.

Claims

1. A device for distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, the device comprising:a first input for receiving a first cable wherein said first cable transports a current and a first signal (Control pilot signal) from the EVSE;a modulator for modulating said first signal from the EVSE thereby communicating with the EVSE a current requirement;a splitter for dividing said current into a plurality of partial currents; anda plurality of outputs for transferring said partial currents from said splitter through said second cables.

2. A device according to claim 1 wherein said splitter comprises a processor and at least one switch wherein said processor controls said switch, thereby directing said partial current to one or both of said outputs.

3. A device according to claim 2 wherein said switches comprise contactors.

4. A device according to any preceding claim wherein said device further comprises a priority system that prioritises electric vehicles connected to said outputs according to a second input.

5. A device according to claim 4 wherein said second input comprises a user input wherein a user sets said priority of the electric vehicles.

6. A device according to any preceding claim further comprising a rectifier for rectifying said first signal to generate a rectified signal wherein said rectified signal provides power to said device.

7. A device according to any preceding claim wherein said first signal comprises a control pilot signal.

8. A device according to any preceding claim wherein said modulator comprises a pulse width modulator.

9. A device according to any of claims 1 to 7 wherein said modulator comprises a switchable resistor network.

10. A device according to any of claims 1 to 7 wherein said modulator comprises a controllable voltage source.

11. A method of distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, comprising the steps:connecting a device comprising an input, a plurality of outputs, a modulator and a splitter to an EVSE;receiving at least one signal from the EVSE through said input; modulating said at least one signal to produce a modulated signal;sending said modulated signal back to said EVSE through said input;the EVSE receiving said modulated signal and sending a current to said device;dividing said current into partial currents using said splitter; anddelivering said partial currents through said outputs.

12. A method according to claim 11 wherein said splitter comprises a processor and at least one switch wherein said processor controls said switch, thereby directing said partial current to one or both of said outputs.

13. A method according to claim 12 wherein said switches comprise contactors.

14. A method according to any of claims 11 to 13 further comprising the step prioritising electric vehicles connected to said outputs according to a second input.

15. A method according to claim 14 wherein said second input comprises a user input wherein a user sets said priority of the electric vehicles.

16. A method according to any of claims 11 to 15 further comprising the step rectifying said first signal to generate a rectified signal wherein said rectified signal provides power to said device.5 17. A method according to any of claims 11 to 16 wherein saidfirst signal comprises a control pilot signal.

18. A method according to any of claims 11 to 17 wherein said modulator comprises a pulse width modulator.

19. A method according to any of claims 11 to 17 wherein said 10 modulator comprises a switchable resistor network.

20. A method according to any of claims 11 to 17 wherein said modulator comprises a controllable voltage source.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:28 02 25Claims1. A device for distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, the device comprising:5 a first input for receiving a first cable wherein said first cable transports a current and a first signal from the EVSE;a modulator for modulating said first signal from the EVSE thereby communicating with the EVSE a current requirement;a splitter for dividing said current into a plurality of partial 10 currents;a plurality of outputs for transferring said partial currents from said splitter through said second cables; anda rectifier for rectifying said first signal to generate a rectified signal wherein said rectified signal provides power 15 to said device.

2. A device according to claim 1 wherein said splitter comprises a processor and at least one switch wherein said processor controls said switch, thereby directing said partial current to one or both of said outputs20 3. A device according to claim 2 wherein said switchescomprise contactors.

4. A device according to any preceding claim wherein said device further comprises a priority system that prioritises electric vehicles connected to said outputs according to a 25 second input.

5. A device according to claim 4 wherein said second input comprises a user input wherein a user sets said priority of the electric vehicles.

6. A device according to any preceding claim wherein said 30 first signal comprises a control pilot signal.

7. A device according to any preceding claim wherein said modulator comprises a pulse width modulator.

8. A device according to any of claims 1 to 7 wherein said modulator comprises a switchable resistor network.5 9. A device according to any of claims 1 to 7 wherein saidmodulator comprises a controllable voltage source.

10. A method of distributing current from an electric vehicle supply equipment (EVSE) to a plurality of outputs through a plurality of cables, comprising the steps:10 connecting a device comprising an input, a plurality of outputs, a modulator and a splitter to an EVSE;receiving at least one signal from the EVSE through said input; modulating said at least one signal to produce a modulated signal;£^15 sending said modulated signal back to said EVSE through said input;CMthe EVSE receiving said modulated signal and sending a current to said device;00dividing said current into partial currents using said splitter;20 delivering said partial currents through said outputs; andrectifying said first signal to generate a rectified signal wherein said rectified signal provides power to said device.

11. A method according to claim 10 wherein said splitter comprises a processor and at least one switch wherein said 25 processor controls said switch, thereby directing said partial current to one or both of said outputs.

12. A method according to claim 11 wherein said switches comprise contactors.

13. A method according to any of claims 10 to 12 further 30 comprising the step prioritising electric vehicles connected to said outputs according to a second input.

14. A method according to claim 13 wherein said second input comprises a user input wherein a user sets said priority of the electric vehicles.

15. A method according to any of claims 10 to 14 wherein said 5 first signal comprises a control pilot signal.

16. A method according to any of claims 10 to 15 wherein said modulator comprises a pulse width modulator.

17. A method according to any of claims 10 to 15 wherein said modulator comprises a switchable resistor network.10 18. A method according to any of claims 10 to 15 wherein saidmodulator comprises a controllable voltage source.28 02 25s

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