Description:METHODS AND SYSTEMS FOR VEHICLE TO VEHICLE CHARGING OF ELECTRIC VEHICLES

TECHNICAL FIELD
[0001] The present disclosure, in general, relates to charging of an electric vehicle. The present disclosure, particularly, relates to methods and systems for vehicle-to-vehicle charging of electric vehicles.

BACKGROUND
[0002] Electric vehicles are of great interest for transportation applications and can provide benefits of low or zero emissions, quiet operation, and reduced dependence upon fossil fuels. Conventional batteries for electric vehicles may include lithium-ion batteries, nickel-metal-hydride batteries, cobalt dioxide batteries, and others. The batteries of electric vehicles are rechargeable at home or at dedicated electric vehicle charging stations. Generally, a charging cable is used to connect the source of charging (electric vehicle charging station) with the electric vehicle. The charging cable may vary as per the source of charging.
[0003] In the ongoing evolving era of electric vehicles, limited travelling range is a major apprehension due to limited availability of charging infrastructure. For electric vehicles to become a popular option among the customers, extensive charging network needs to be created. This will provide more confidence to the customers while travelling longer distances. However, creating an extensive charging network needs a lot of capital investment and time.
[0004] For the time being, a need arises to have some sort of portably available source of charging using existing standard cables.
[0005] Currently, vehicle to vehicle charging is being offered by very limited electric vehicle manufacturers. The vehicle-to-vehicle charging is performed using a bi-direction on-board charger which employs usage of non-standard connectors and a home charging cable.
[0006] When charging of electric vehicle is done using the bi-directional on-board charger i.e. Mode 2 charging, other than precautionary checks of Electric vehicles, communication is required between the source of charging and the electric vehicle. The communication is done by an in-cable control box present in home charging cable for mode 2 charging.
[0007] Referring to Figure 1 illustrating vehicle to vehicle charging in accordance with the existing art. In existing vehicle to vehicle charging, load vehicle is charged using the Home Charging Cable 101 of load vehicle which is plugged in a special connector 102 fitted onto the charging outlet of source vehicle 103. The type of connector depends on the AC side plug type of the home charging cable. Use of special connector 102 does help in solving problem of limited travelling range, but the special connector 102 may vary from region to region. In addition, charging rate is affected by charging cable 101 type because current rating of the home charging cable 101 is low because of domestic current usage limitations. Thus, vehicle to vehicle charging won’t be able to utilize full capacity of bi-directional on-board charger.
[0008] Accordingly, there is a need for standard methods and systems for vehicle to vehcile charging of the electric vehicle.

SUMMARY
[0009] This summary is provided to introduce concepts related to methods and systems for vehicle to vehicle charging of the electric vehicle. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0010] The present subject matter relates to a method performed by a source vehicle for vehicle to vehicle charging. The method comprises enabling control pilot (CP) generator unit and proximity pilot (PP) generator unit of the source vehicle when mode selector switch is in “source mode”, wherein the proximity pilot generator unit transmit a proximity pilot signal to the load vehicle; determining, by vehicle control unit, operating parameters of the source vehicle; determining, by the vehicle control unit, whether or not the operating parameters of the source vehicle are within corresponding pre-defined limits stored in a memory unit; generating, by the control pilot generator unit, a control pilot signal when the operating parameters of the source vehicle are within predefined limits; transmitting, by the control pilot generator unit, the generated control pilot signal to the load vehicle; and transmitting charging current, through a charging cable, from the source vehicle to the load vehicle based on the maximum charging current value transmitted to the load vehicle by the control pilot signal.
[0011] In an aspect, the operating parameters determined by the vehicle control unit of the source vehicle includes isolation resistance, leakage current, battery state of charge and battery temperature.
[0012] In an aspect, the control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle.
[0013] In an aspect, when the operating parameters of the source vehicle are not within their corresponding predefined limits the control pilot generator unit does not transmit the control pilot signal.
[0014] In an aspect, an indication is sent to the user about the selected mode of the mode selection switch.
[0015] The present subject matter further relates to a system for source vehicle for vehicle to vehicle charging. The system comprises a charging cable, a vehicle control unit, a memory unit, a proximity pilot generator unit and a control pilot generator unit. The charging cable is operatively connecting the source vehicle with a load vehicle. The charging cable is configured to transfer charging current from the source vehicle to the load vehicle. The vehicle control unit is configured to determine operating parameters of the source vehicle. The memory unit is operatively connected to the vehicle control unit. The memory unit is configured to store pre-defined limits of the operating parameters of the source vehicle. The vehicle control unit determines whether or not the operating parameters of the source vehicle are within corresponding pre-defined limits stored in the memory unit. The proximity pilot generator unit is configured to generate a proximity pilot signal and transmitting the proximity pilot signal to the load vehicle. The control pilot generator unit is configured to generate a control pilot signal based on maximum possible charging current based on rated power of bi-directional on-board charger when the operating parameters of the source vehicle are within predefined limits. The charging current is transmitted from the source vehicle to the load vehicle based on the transmitted control pilot signal.
[0016] In an aspect, the vehicle control unit determines the operating parameter including isolation resistance, leakage current, battery state of charge and battery temperature.
[0017] In an aspect, the control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle.
[0018] In an aspect, the control pilot generator unit does not transmit the control pilot signal when the operating parameters of the source vehicle are not within their corresponding predefined limits.
[0019] In an aspect, an indicator is provided to indicate the user about the selected mode of the mode selection switch.
[0020] The present subject matter further relates to a method performed by a load vehicle for vehicle to vehicle charging. The method comprises enabling, control pilot receiver unit and proximity pilot receiver unit of the load vehicle when mode selector switch is in “load mode”; receiving, by the proximity pilot receiver unit, a proximity pilot signal from the source vehicle; determining, by vehicle control unit, operating parameters of the load vehicle when the received proximity pilot signal is fine; determining, by the vehicle control unit, whether or not the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit; receiving, by the control pilot receiver unit, a control pilot signal transmitted by the source vehicle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle; closing S2 switch when the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit; receiving charging current from the source vehicle, through a charging cable, based on demand by load vehicle.
[0021] In an aspect, the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle.
[0022] In an aspect, the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle.
[0023] In an aspect, the S2 switch is opened after charging of the load vehicle is completed.
[0024] In an aspect, the proximity pilot signal is not fine, an indication is sent to the user.
[0025] In an aspect, the S2 switch is not closed when the operating parameters of the load vehicle is not within the corresponding pre-defined limits stored in the memory unit.
[0026] The present subject matter further relates to a system for a load vehicle for vehicle to vehicle charging. The system comprises a charging cable, a vehicle control unit, a memory unit, a proximity pilot receiver unit and a control pilot receiver unit. The charging cable is operatively connecting the load vehicle with a source vehicle. The charging cable is configured to transfer power from the source vehicle to the load vehicle; The vehicle control unit is configured to determine operating parameters of the load vehicle. The memory unit is operatively connected to the vehicle control unit. The memory unit is configured to store pre-defined limits of the operating parameters of the load vehicle. The vehicle control unit determines whether or not the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit. The proximity pilot receiver unit is configured to receive a proximity pilot signal from the source vehicle. The control pilot receiver unit is configured to receive a control pilot signal transmitted by the source vehicle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle. The charging of the load vehicle is determined by a charging controller.
[0027] In an aspect, the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle.
[0028] In an aspect, the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle.
[0029] In an aspect, wherein the S2 switch is opened after charging of the load vehicle is completed.
[0030] In an aspect, an indicator is provided to indicate the user when the proximity pilot signal is not fine.
[0031] In an aspect, the S2 switch is not closed when the operating parameters of the load vehicle is not within the corresponding pre-defined limits stored in the memory unit.
[0032] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0033] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF FIGURES
[0034] The illustrated embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0035] FIG. 1 illustrates vehicle to vehicle charging in accordance with the existing art;
[0036] FIG. 2 illustrates an exemplary system for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0037] FIG. 3a illustrates an exemplary system for a source vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0038] FIG. 3b illustrates an exemplary system for a load vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0039] FIG. 4 illustrates standard control pilot circuit for charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0040] FIG. 5a illustrates flow chart of method performed by the source vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0041] FIG. 5b illustrates flow chart of method performed by the load vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure; and
[0042] FIG. 6 illustrates flow chart of vehicle to vehicle charging in accordance with an exemplary embodiments of the present disclosure.
[0043] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0044] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.

EXEMPLARY IMPLEMENTATIONS
[0045] While the present disclosure may be embodied in various forms, there are shown in the drawings, and will hereinafter be described, some exemplary and non-limiting embodiments, with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. Not all of the depicted components described in this disclosure may be required, however, and some implementations may include additional, different, or fewer components from those expressly described in this disclosure. Variations in the arrangement and type of the components may be made without departing from the scope of the claims as set forth herein.
[0046] Some embodiments of this invention, illustrating all its features, will be discussed in detail.
[0047] The techniques described below may be implemented using one or more computer programs executed on (or executable by) a programmable computer including any combination of any number of the following: a processor, a sensor, a storage medium readable and/or writable by the processor (including for example volatile and non-volatile memory and/or storage elements), plurality of inputs units, plurality of output devices and networking devices.
[0048] Method steps as disclosed by present disclosure may be performed by one or more computer processors executing a program tangibly embodied on a computer-readable medium to perform functions of the invention by operating on input and generating output. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, the processor receives (reads) instructions and content from a memory (such as a read only memory and/or random access memory) and writes (stores) instructions and content to the memory. Storage devices suitable for tangibly embodying computer program instructions and content include, for example, all forms of non-volatile memory, such as semiconductor memory devices, including EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disk and removable disks, magneto-optical disks, and CD-ROMs. Any of the foregoing may be supplemented by, or incorporated in, specially-designed ASICs (application specific integrated circuits) or FPGAs (Field-Programmable Gate Arrays).
[0049] Any content disclosed herein may be implemented, for example, in one or more content structures tangibly stored on a non-transitory computer-readable medium. Embodiments of the invention may store such content in such content structure(s) and read such content from such content structure(s).
[0050] The present disclosure provides methods and systems for vehicle to vehicle charging of the electric vehicle. In this disclosure it is presumed that both the electric vehicles are capable for vehicle-to-vehicle charging. Further, in this disclosure electric vehicle acting as source of charging is referred as “Source Vehicle” and the other electric vehicle (vehicle to be charged) is referred as “Load Vehicle”.
[0051] FIG. 2 illustrates an exemplary system for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure. The system 200 comprises a system 201 for source vehicle, a system 202 for load vehicle and a charging cable 203. The system 201 for source vehicle is implemented in a source vehicle for vehicle-to-vehicle charging. The system 202 for load vehicle is implemented in a load vehicle for vehicle-to-vehicle charging. The load vehicle is connected to the source vehicle through the charging cable 203. Charging current is transferred from the source vehicle to the load vehicle through the charging cable 203. The system 201 for source vehicle and the system 202 for load vehicles are connected to each other with the charging cable 203 to work concurrently. Selection of vehicle to act as a source vehicle or a load vehicle is based on mode selection through a mode selection switch. The user can select ‘source mode’ and provide charging current to other vehicle. Similarly, the user can select ‘load mode’ and receive charging current from the other vehicle. The system for source vehicle and the system for load vehicles are discussed in detail in FIGS. 3a and 3b. Similarly, the method steps by the source vehicle and the method steps by the load vehicle are performed simultaneously.
[0052] FIG. 3a illustrates an exemplary system for a source vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure. When the mode selector switch is in “source mode”, the vehicle acts as source vehicle. The system 201 for source vehicle comprises a charging cable 203, a vehicle control unit 301a, a memory unit 302a, a proximity pilot generator unit 303a, a proximity pilot receiver circuit 306a, a control pilot receiver unit 304a and a control pilot generator unit 305a. The charging cable 203 operatively connects the source vehicle with the load vehicle. The charging cable 203 is configured to transfer charging current from the source vehicle to the load vehicle. In an aspect, the charging cable 203 is a standard mode 3 charging cable to perform vehicle to vehicle charging. The vehicle control unit 301a of the source vehicle is configured to determine operating parameters of the source vehicle. The operating parameters are determined to check robustness of the battery of the source vehicle to discharge requisite charging current. The operating parameters include isolation resistance, leakage current, battery state of charge and battery temperature. The memory unit 302a is operatively connected to the vehicle control unit 301a. The memory unit 302a is configured to store pre-defined limits of the operating parameters of the source vehicle. The vehicle control unit 301a which is operatively connected to the memory unit 302a is configured to determine whether or not the operating parameters of the source vehicle are within the corresponding pre-defined limits stored in the memory unit 302a. If the operating parameters of the source vehicle are within the pre-defined limits, it implies that the source vehicle is capable of providing charging current to the load vehicle. If the operating parameters of the source vehicle are not within the pre-defined limits, it implies that the source vehicle is not capable of providing charging current to the load vehicle.
[0053] The Proximity Pilot Receiver Unit 306a is operatively inactive since the mode selector is source mode.
[0054] The Proximity Pilot is provided in the system 201 to serve as a charge cable detection. The proximity pilot generator unit 303a is operatively connected to proximity pilot receiver circuit 306a using a switching relay. The vehicle is acting as source, so proximity pilot generator unit 303a will be operating. The proximity pilot generator unit 303a is configured to generate a proximity pilot signal and transmit the proximity pilot signal to the load vehicle.
[0055] The control pilot receiver unit 304a is operatively inactive since the mode selector switch is in source mode.
[0056] The control pilot generator unit 305a is operatively connected to the control pilot receiver unit 304a using a switching relay. The control pilot generator unit 305a is configured to generate a control pilot signal based on the maximum possible charging current which is predefined based on the rated power of Bi-directional On-board charger present in the vehicle. The control pilot generator unit 305a generates the control pilot signal when the operating parameters of the source vehicle are within predefined limits. The control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle. Further, the control pilot generator unit 305a is configured to transmit the generated control pilot signal to the load vehicle. The control pilot generator unit 305a ensures that the load vehicle is communicated with the maximum charging current value that can be drawn from the source vehicle. The control pilot generator unit 305a does not transmit the control pilot signal when the operating parameters of the source vehicle are not within their corresponding predefined limits.
[0057] In addition, an indicator is provided in the source vehicle to indicate the user about the selected mode of the mode selection switch.
[0058] FIG. 3b illustrates an exemplary system for a load vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure. When the mode selector switch is in “load mode”, the vehicle acts as load vehicle. The system 202 for load vehicle comprises a charging cable 203, a vehicle control unit 301b, a memory unit 302b, a proximity pilot generator unit 303b, a proximity pilot receiver unit 306b, a control pilot receiver unit 304b and a control pilot generator unit 305b. The charging cable 203 operatively connects the source vehicle with the load vehicle. The charging cable 203 is configured to transfer charging current from the source vehicle to the load vehicle. In an aspect, the charging cable 203 is a standard mode 3 charging cable to perform vehicle to vehicle charging. The vehicle control unit 301b of the load vehicle is configured to determine operating parameters of the load vehicle. The operating parameters are determined to check robustness of the battery of the load vehicle to accept requisite charging current. The operating parameters include isolation resistance, leakage current, battery state of charge and battery temperature. The memory unit 302b is operatively connected to the vehicle control unit 301b. The memory unit 302b is configured to store pre-defined limits of the operating parameters of the load vehicle. The vehicle control unit 301b which is operatively connected to the memory unit 302b is configured to determine whether or not the operating parameters of the load vehicle are within the corresponding pre-defined limits stored in the memory unit 302b. If the operating parameters of the load vehicle are within the pre-defined limit, it implies that the load vehicle is capable of receiving charging current from the source vehicle. Accordingly, S2 switch is closed in the control pilot receiving circuit of the load vehicle. If the operating parameters of the load vehicle are not within the pre-defined limit, it implies that the load vehicle is not capable of receiving charging current from the source vehicle.
[0059] The Proximity Pilot Generator Unit 303b is operatively inactive since the mode selector is source mode.
[0060] The Proximity Pilot is provided in the system 202 to serve as a charge cable detection. The proximity pilot generator unit 303b is operatively connected to proximity pilot receiver circuit 306b using a switching relay. The vehicle is acting as load so proximity pilot receiver unit 306b will be operating. The proximity pilot receiver unit 306b is provided in the system 202 to serve as a charge cable detection. The proximity pilot receiver unit 306b is configured to receiver a proximity pilot signal from the source vehicle. The proximity pilot receiver unit 306b is operatively connected to the vehicle control unit 301b to prevent any movement while connecting to the source vehicle.
[0061] The control pilot generator unit 305b is operatively inactive since the mode selector switch is in load mode.
[0062] The control pilot receiver unit 304b is operatively connected to the control pilot generator unit 305b using a switching relay. The control pilot receiver unit 304b is configured to receive a control pilot signal transmitted by the source vehicle. The control pilot signal transmitted by the source vehicle communicates the maximum charging current that can be drawn from the source vehicle to charge the load vehicle. The charging current received by the load vehicle is determined by a charging controller present in the vehicle control unit 301b. In an aspect, the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle. In an aspect, the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle. S2 switch is closed and charging is started.
[0063] The S2 switch is opened after the charging of the load vehicle is completed. In addition, an indicator is provided to indicate the user when the proximity pilot signal is not fine.
[0064] FIG. 4 illustrates standard control pilot circuit for charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure.
[0065] FIG. 5a illustrates flow chart of method performed by the source vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure.
[0066] At step 502a, the method 500a includes enabling control pilot generator unit 305a and proximity pilot generator unit 303a of the source vehicle. The proximity pilot generator unit 303a is enabled in the source vehicle to ensure proper connection of the source vehicle to the load vehicle. Further, the control pilot generator unit 305a is enabled based on the mode chosen on the mode selector switch. The control pilot generator unit 305a is enabled when the mode selector switch is in “source mode”.
[0067] At step 504a, the method 500a includes determining operating parameters of source vehicle. The operating parameters are determined by the vehicle control unit 301a. The operating parameters are determined to check robustness of the battery of the source vehicle to discharge requisite charging current. The operating parameters include isolation resistance, leakage current, battery state of charge and battery temperature.
[0068] At step 506a, the method 500a includes determining whether operating parameters are within pre-defined limits. The vehicle control unit 301a is configured to determine whether or not the operating parameters of the source vehicle are within corresponding pre-defined limits stored in the memory unit 302a. The memory unit 302a is operatively connected to the vehicle control unit 301a. The memory unit 302a is configured to store pre-defined limits of the operating parameters of the source vehicle. The vehicle control unit 301a which is operatively connected to the memory unit 302a is configured to determine whether or not the operating parameters of the source vehicle are within the corresponding pre-defined limits stored in the memory unit 302a. If the operating parameters of the source vehicle are within the pre-defined limits, it implies that the source vehicle is capable of providing charging current to the load vehicle. If the operating parameters of the source vehicle are not within the pre-defined limit, it implies that the source vehicle is not capable of providing charging current to the load vehicle.
[0069] At step 508a, the method 500a includes generating control pilot signal. The control pilot signal is generated by the control pilot generator unit 305a. The control pilot generator unit 305a generates the control pilot signal when the operating parameters of the source vehicle are within predefined limits. The control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle. In an aspect, the mode selector switch status indication is sent to the user.
[0070] At step 510a, the method 500a includes transmitting control pilot signal to the load vehicle. The control pilot generator unit 305a is configured to transmit the generated control pilot signal to the load vehicle. In an aspect, when the operating parameters determined by the vehicle control unit 301a is not within the pre-defined limits, the control pilot generator unit 305a does not transmit the control pilot signal.
[0071] At step 512a, the method 500a includes transmitting charging current from the source vehicle to load vehicle. The charging current transmitted from the source vehicle is limited by the maximum charging current value transmitted to the load vehicle through control pilot signal.
[0072] FIG. 5b illustrates flow chart of method performed by the load vehicle for vehicle to vehicle charging of the electric vehicle that can be utilized to implement one or more exemplary embodiments of the present disclosure.
[0073] At step 502b, the method 500b includes enabling control pilot receiver unit 304b and proximity pilot receiver unit 306b. The control pilot receiver unit 304b of the load vehicle is enabled based on the mode chosen on the mode selector switch. The control pilot receiver unit 304b is enabled when the mode selector switch is in “load mode”. Further, the proximity pilot receiver unit 306b is enabled to ensure proper connection between the load vehicle and the source vehicle.
[0074] At step 504b, the method 500b includes receiving a proximity pilot signal from the source vehicle. The proximity pilot receiver unit 306b receives the proximity pilot signal transmitted by the proximity pilot generator unit 303a of the source vehicle. If the proximity pilot signal is fine, it indicates that the charging connection between the source vehicle and the load vehicle is fine. In an aspect, if the proximity pilot signal is not fine an indication is sent to the user to check the connection of the charging cable 203.
[0075] At step 506b, the method 500b includes determining operating parameters of the load vehicle. The vehicle control unit 301b determines the operating parameters of the load vehicle when the received proximity pilot signal is fine. The operating parameters are determined to check robustness of the battery of the load vehicle to discharge requisite charging current. The operating parameters include isolation resistance, leakage current, battery state of charge and battery temperature.
[0076] At step 508b, the method 500b includes determining whether operating parameters are within pre-defined limits. The vehicle control unit 301b determines whether or not the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit 302b. The memory unit 302b is operatively connected to the vehicle control unit 301b. The memory unit 302b is configured to store pre-defined limits of the operating parameters of the load vehicle. The vehicle control unit 301b which is operatively connected to the memory unit 302b is configured to determine whether or not the operating parameters of the load vehicle are within the corresponding pre-defined limits stored in the memory unit 302b. If the operating parameters of the load vehicle are within the pre-defined limits, it implies that the load vehicle is capable of receiving charging current from the source vehicle. If the operating parameters of the load vehicle are not within the pre-defined limit, it implies that the load vehicle is not capable of receiving charging current from the source vehicle.
[0077] At step 510b, the method 500b includes receiving control pilot signal from the source vehicle. The control pilot receiver unit 304b of the load vehicle receives a control pilot signal transmitted by the control pilot generator unit 303a of the source vehicle. The control pilot signal communicates maximum charging current that can be drawn from the source vehicle to charge the load vehicle.
[0078] At step 512b, the method 500b includes closing S2 switch of Control pilot receiver circuit, when the operating parameters of the of the load vehicle are within corresponding pre-defined limits stored in the memory unit 302b. Closing of the S2 switch ensures that the load vehicle is prepared to receive the charging current. In an aspect, the S2 switch is not closed when the operating parameters of the load vehicle is not within the corresponding pre-defined limits stored in the memory unit 302b.
[0079] At step 514b, the method 500b includes receiving charging current from the source vehicle. The charging current received by the load vehicle depends on the maximum charging current that can be received on the load vehicle. In an aspect, the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle. In an aspect, the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle. The S2 switch is opened after charging of the load vehicle is completed.
WORKING EMBODIMENT
[0080] FIG. 6 illustrates flow chart of vehicle to vehicle charging in accordance with an exemplary embodiments of the present disclosure.
[0081] The charging of load vehicle by the source vehicle is initiated by connecting the load vehicle and the source vehicle with the charging cable. The control pilot generator unit of the source vehicle and the proximity pilot generator unit of the source vehicle are enabled. Similarly, control pilot receiver unit of the load vehicle and the proximity pilot receiver unit of the load vehicle are enabled. The proximity pilot generator unit of the source vehicle generates a proximity pilot signal and transmits the same to the load vehicle. The proximity pilot receiver unit of the load vehicle receives the proximity pilot signal from the source vehicle. The vehicle control unit of the load vehicle determines the operating parameters of the load vehicle when the received proximity pilot signal is fine. Simultaneously, the vehicle control unit of the source vehicle determines the operating parameters of the source vehicle. The vehicle control unit of the load vehicle determine whether or not the determined operating parameters are within the corresponding stored pre-defined limit of the operational parameter. S2 switch is closed when the operating parameters are within the pre-defined limits. The control pilot generator unit of the source vehicle generates and transmits a control pilot signal to the load vehicle to communicate the maximum charging current that can be drawn up from the source vehicle. The charging current is sent from the source vehicle to the load vehicle. The charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle. The charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle. After charging the load vehicle, the S2 switch is opened.
ADVANTAGES
[0082] The present disclosure provides methods and systems for vehicle to vehicle charging of the electric vehicle. The disclosed methods and systems ensure use of standard accessories by eliminating any need to use special connector. Accordingly, the proposed subject matter provide solution to the travelling range problem of the electric vehicle. In addition, the proposed subject matter ensures faster charging rate as the standard charging cable can be used up to maximum capacity of the On-board charger of the vehicles involved.
[0083] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0084] It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise, as apparent from the discussion herein, it is appreciated that throughout the description, discussions utilizing terms such as “receiving,” or “retrieving,” or “comparing,” or “generating,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
[0085] The exemplary embodiment also relates to a system for performing the operations discussed herein. This system may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, solid state drives, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
[0086] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0087] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0088] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
, Claims:We Claim:
1. A method (500a) performed by a source vehicle for vehicle to vehicle charging, the method (500a) comprises:
enabling (502a), control pilot generator unit (305a) and proximity pilot generator unit (303a) of the source vehicle when mode selector switch is in “source mode”, wherein the proximity pilot generator unit (303a) transmit a proximity pilot signal to a load vehicle;
determining (504a), by vehicle control unit (301a), operating parameters of the source vehicle;
determining (506a), by the vehicle control unit (301a), whether or not the operating parameters of the source vehicle are within corresponding pre-defined limits stored in a memory unit (302a);
generating (508a), by the control pilot generator unit (305a), a control pilot signal when the operating parameters of the source vehicle are within predefined limits;
transmitting (510a), by the control pilot generator unit (305a), the generated control pilot signal to the load vehicle; and
transmitting (512a) charging current, through a charging cable (203), from the source vehicle to the load vehicle based on the maximum charging current value transmitted to the load vehicle by the control pilot signal.
2. The method (500a) as claimed in claim 1, wherein the operating parameters determined by the vehicle control unit (301a) of the source vehicle includes isolation resistance, leakage current, battery state of charge and battery temperature.
3. The method (500a) as claimed in claim 1, wherein the control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle.
4. The method (500a) as claimed in claim 1, wherein when the operating parameters of the source vehicle are not within their corresponding predefined limits the control pilot generator unit (305a) does not transmit the control pilot signal.
5. The method (500a) as claimed in claim 1, wherein an indication is sent to the user about the selected mode of the mode selection switch.
6. A system (201) for a source vehicle for vehicle to vehicle charging, the system (201) comprises:
a charging cable (203) operatively connecting the source vehicle with a load vehicle, wherein the charging cable (203) is configured to transfer charging current from the source vehicle to the load vehicle;
a vehicle control unit (301a) configured to determine operating parameters of the source vehicle;
a memory unit (302a), operatively connected to the vehicle control unit (301a), configured to store pre-defined limits of the operating parameters of the source vehicle, wherein the vehicle control unit (301a) determines whether or not the operating parameters of the source vehicle are within corresponding pre-defined limits stored in the memory unit (302a);
a proximity pilot generator unit (303a) configured to generate a proximity pilot signal and transmitting the proximity pilot signal to the load vehicle; and

a control pilot generator unit (305a) configured to:
generate a control pilot signal based on the maximum possible charging current based on rated power of bi-directional on-board charger when the operating parameters of the source vehicle are within predefined limits; and
transmit the generated control pilot signal to the load vehicle, wherein the charging current is transmitted from the source vehicle to the load vehicle based on the transmitted control pilot signal.
7. The system (201) as claimed in claim 6, wherein the vehicle control unit (301a) determines the operating parameter including isolation resistance, leakage current, battery state of charge and battery temperature.
8. The system (201) as claimed in claim 6, wherein the control pilot signal is a pulse width modulation PWM signal of appropriate duty cycle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle.
9. The system (201) as claimed in claim 6, wherein the control pilot generator unit (305a) does not transmit the control pilot signal when the operating parameters of the source vehicle are not within their corresponding predefined limits.
10. The system (201) as claimed in claim 6, wherein an indicator is provided to indicate the user about the selected mode of the mode selection switch.
11. A method (500b) performed by a load vehicle for vehicle to vehicle charging, the method (500b) comprises:
enabling (502b), control pilot receiver unit (304b) and proximity pilot receiver unit (303b) of the load vehicle when mode selector switch is in “load mode”;
receiving (504b), by the proximity pilot receiver unit (303b), a proximity pilot signal from the source vehicle;
determining (506b), by vehicle control unit (301b), operating parameters of the load vehicle when the received proximity pilot signal is fine;
determining (508b), by the vehicle control unit (301b), whether or not the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit (302b);
receiving (510b), by the control pilot receiver unit (304b), a control pilot signal transmitted by the source vehicle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle;
closing (512b) S2 switch when the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit;
receiving (514b) charging current from the source vehicle, through a charging cable (203), based on the maximum charging current that can be received by the load vehicle.
12. The method (500b) as claimed in claim 11, wherein the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle.
13. The method (500b) as claimed in claim 11, wherein the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle.
14. The method (500b) as claimed in claim 11, wherein the S2 switch is opened after charging of the load vehicle is completed.
15. The method (500b) as claimed in claim 11, when the proximity pilot signal is not fine, an indication is sent to the user.
16. The method (500b) as claimed in claim 11, wherein the S2 switch is not closed when the operating parameters of the load vehicle is not within the corresponding pre-defined limits stored in the memory unit (302b).
17. A system (202) for a load vehicle for vehicle to vehicle charging, the system (202) comprises:
a charging cable (203) operatively connecting the load vehicle with a source vehicle, wherein the charging cable (203) is configured to transfer power from the source vehicle to the load vehicle;
a vehicle control unit (301b) configured to determine operating parameters of the load vehicle;
a memory unit (302b), operatively connected to the vehicle control unit (301b), configured to store pre-defined limits of the operating parameters of the load vehicle, wherein the vehicle control unit (301b) determines whether or not the operating parameters of the load vehicle are within corresponding pre-defined limits stored in a memory unit (302b);
a proximity pilot receiver unit (303b) configured to receive a proximity pilot signal from the source vehicle; and
a control pilot receiver unit (304b) configured to receive a control pilot signal transmitted by the source vehicle communicating maximum charging current that can be drawn from the source vehicle to charge the load vehicle, wherein charging of the load vehicle is determined by a charging controller.
18. The system (202) as claimed in claim 17, wherein the charging current is equal to the maximum charging current drawn from the source vehicle when the maximum charging current that can be received by the load vehicle is more than or equal to maximum charging current drawn from the source vehicle.
19. The system (202) as claimed in claim 17, wherein the charging current is equal to the maximum charging current that can be received by the load vehicle when the maximum charging current that can be received by the load vehicle is less than maximum charging current drawn from the source vehicle.
20. The system (202) as claimed in claim 17, wherein the S2 switch is opened after charging of the load vehicle is completed.
21. The system (202) as claimed in claim 17, when an indicator is provided to indicate the user when the proximity pilot signal is not fine.
22. The system (202) as claimed in claim 17, wherein the S2 switch is not closed when the operating parameters of the load vehicle is not within the corresponding pre-defined limits stored in the memory unit (302b).
23. A method for vehicle to vehicle charging, the method comprises method (500a) performed by the source vehicle as claimed in claims 1-5 and method (500b) performed by the load vehicle as claimed in claims 11-16.
24. The method as claimed in claim 23, wherein the method steps (502a, 504a, 506a, 508a, 510a, 512a) by the source vehicle and the method steps (502b, 504b, 506b, 508b, 510b, 512b, 514b) by the load vehicle are performed simultaneously.
25. A system for vehicle to vehicle charging, the system comprises system (201) for source vehicle as claimed in claims 6-10 and system (202) for load vehicle as claimed in claims 17-22.
26. The system as claimed in claim 25, wherein the system (201) for source vehicle and the system (202) for load vehicle are connected to each other with a charging cable (203) to work concurrently.