DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

TITLE OF THE INVENTION
SYSTEM AND METHOD FOR CHARGING AN ELECTRIC VEHICLE

APPLICANT:
Servotech Power Systems Ltd., an Indian company of the address 806, 8th Floor, Crown Heights, Near Hotel Crowne Plaza, Sector-10, Rohini, Delhi, North West, Pin 110085 Delhi, India

The following specification particularly describes the invention and the manner in which it is to be performed:
FIELD OF INVENTION
[001] The present disclosure relates to automobiles. More particularly, the present disclosure relates to a system and method for charging an electric vehicle.
BACKGROUND OF INVENTION
[002] The use of electric vehicles is growing rapidly across the world due to several benefits offered by the electric vehicles, such as, improved fuel efficiency, reduced emissions, lower operational costs, etc. An electric vehicle typically utilizes one or more rechargeable batteries as the source of energy for driving the electric vehicle as well as for various other systems in the electric car. The electric vehicles can be charged through a charging station. The charging station may be provided at user premises or at dedicated locations.
[003] Multiple electric vehicles from several automobile manufacturers are available in the market. These electric vehicles may come with different charging requirements in terms of voltage, current and/or power. Further, several companies are providing charging infrastructure, e.g., charging stations, to charge electric vehicles. Different charging standards have been defined to facilitate interoperability between electric vehicles of different automobile manufacturer and the companies providing the charging infrastructure. Examples of the charging standards include GB/T, CHAdeMO, Combined Charging System (CCS), North American Charging Standard (NACS).
[004] However, despite these attempts of standardizing electric vehicle charging, there are still several drawbacks. These charging standards are incompatible with each other. For example, connectors used for connecting the electric vehicle with the charging station can be different between the charging standards, with the result that the electric vehicle of one charging standard cannot even be plugged into a charging station of a different standard. Further, different standards often use different signaling protocols. As a result, an electric vehicle compliant with one standard is not able to detect a charging station using a different standard and/or communicate with it even though they could be plugged with each other. Moreover, voltage ranges and/or current ranges of the protocols may also be different. For example, a vehicle compliant with a charging standard requiring a lower voltage (e.g., electric vehicles compliant with the Bharat DC 001 standard and requiring a voltage, typically between 72V – 90V) cannot be charged using a charging station supporting only a higher voltage (e.g., charging stations compliant with the CCS standard, whose minimum voltage is 200V). Consequently, the user of the electric vehicle is severely restricted in the choice of charging stations for their electric vehicle, especially when the user is traveling.
[005] Therefore, there is a need of a charging device that overcomes drawbacks associated with the current charging infrastructure.
SUMMARY OF THE INVENTION
[006] The present disclosure relates to a system and a method for charging an electric vehicle. In an embodiment, the system includes a device coupled to an electric vehicle supply equipment (EVSE) and an electric vehicle. The device includes a protocol translation module, executed by a first processor, configured to receive a charging request message from the electric vehicle according to a first charging protocol associated with the electric vehicle. The charging request message includes a demand voltage. The protocol translation module is further configured to transmit a translated charging request message comprising the demand voltage, to the EVSE according to a second charging protocol associated with the EVSE. The device further includes a power control module, communicatively coupled to the protocol translation module and executed by the first processor. The power control module is configured to receive the demand voltage from the protocol translation module and generate at least one control signal. The device further includes a power unit including inputs coupled to the EVSE and outputs coupled to the electric vehicle. The power unit is configured to receive the at least one control signal. The power unit is further configured to receive a power signal having the demand voltage from the EVSE at the inputs; and transfer the power signal to the outputs based upon the at least one control signal. The system further includes a power control unit provided in the EVSE and communicatively coupled with the protocol translation module. The power control unit is configured to receive the demand voltage in translated charging request message. The power control unit is further configured to determine that the demand voltage is less than a minimum voltage of a voltage range of the EVSE. In response to determining that the demand voltage is less than the minimum voltage, the power control unit is configured to set an operating mode to a low power mode; and output the power signal having the demand voltage according to the low power mode.
[007] According to an embodiment, the method for charging an electric vehicle includes receiving, by a protocol translation module, a charging request message from an electric vehicle according to a first charging protocol associated with the electric vehicle. The charging request message includes a demand voltage. The method further includes transmitting, by the protocol translation module, a translated charging request message comprising the demand voltage, to an electric vehicle supply equipment (EVSE) according to a second charging protocol associated with the EVSE. The method further includes generating, by a power control module, at least one control signal. The method further includes receiving, by a power control unit provided in the EVSE, the demand voltage in translated charging request message. The method further includes determining, by the power control unit, that the demand voltage is less than a minimum voltage of a voltage range of the EVSE. The method further includes, in response to determining that the demand voltage is less than the minimum voltage, setting, by the power control unit, an operating mode to a low power mode. The method further includes outputting, by the power control unit, a power signal having the demand voltage according to the low power mode. The method further includes receiving, by a power unit, the power signal having the demand voltage. The method further includes transferring, by the power unit, the received power signal to the electric vehicle based upon the at least one control signal.
[008] The foregoing features and other features as well as the advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[009] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[0010] Fig. 1 depicts a system 100 in which a charging device 102 may be deployed, in accordance with one or more embodiment of the present disclosure.
[0011] Fig. 2 depicts a schematic block diagram of the charging device 102, in accordance with an embodiment of the present disclosure.
[0012] Fig. 3 depicts a schematic block diagram of a communication unit 216, in accordance with an embodiment of the present disclosure.
[0013] Fig. 4 depicts a schematic block diagram of a control unit 218, in accordance with an embodiment of the present disclosure.
[0014] Fig. 5 depicts a schematic block diagram of a power unit 220, in accordance with an embodiment of the present disclosure.
[0015] Fig. 6 depicts a flowchart of a method 600 for charging of an electric vehicle 106, in accordance with an embodiment of the present disclosure.
[0016] Fig. 7 depicts a flowchart of a method 700 for translating messages between an EVSE 104 and the electric vehicle 106 compliant with different protocols, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF DRAWINGS
[0017] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0018] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0019] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0020] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0021] The present disclosure provides a system for charging an electric vehicle compliant with a first charging protocol from an electric vehicle supply equipment (EVSE) compliant with a second charging protocol, which is different from the first charging protocol. According to an embodiment, the system includes a charging device interfaced with the electric vehicle and the EVSE, and a power control unit provided in the EVSE. The charging device intercepts charging requirements of the electric vehicle and sends the charging requirements to the EVSE. The charging requirements of the electric vehicle as per the first charging protocol may not match with charging capabilities of the EVSE as per the second charging protocol. For example, a voltage required by the electric vehicle may be outside of a voltage range supported by the EVSE. According to an embodiment, when a demand voltage required by the electric vehicle is lower than a minimum voltage supported by the EVSE, the power unit sets an operating mode in a lower power mode and facilitates that the EVSE delivers a power signal having the demand voltage according to the lower power mode. The charging device transfers the power signal to the electric vehicle. Further, the charging device translates messages from the first charging protocol to the second charging protocol and vice versa, thereby ensuring seamless communication between the electric vehicle and the EVSE despite the difference in the respective charging protocols.
[0022] The proposed system presents several advantages. Unlike conventional devices, the system of the present disclosure enables a user to charge the electric vehicle even when charging requirements of the electric vehicle do not match with charging capabilities of the EVSE. It leads to more charging options for the user, especially when the user is travelling, and consequently, enhances the overall user experience.
[0023] Fig. 1 depicts a system 100 for charging an electric vehicle, according to an embodiment of the present disclosure. The system 100 includes a charging device 102, an electric vehicle supply equipment (EVSE) 104 (interchangeably, referred to as a charging station 104), and an electric vehicle 106. The charging device 102 is coupled to the EVSE 104 and the electric vehicle 106. The electric vehicle 106 may be a battery electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV) or any other vehicle having a rechargeable battery. The electric vehicle 106 may be a car, a bicycle, a motor bike, a bus, a truck, etc. The charging device 102 facilitates charging of the electric vehicle 106 compliant with a first charging protocol (or first protocol) by the EVSE 104 compliant with a second charging protocol (or second protocol), different than the first protocol. A voltage range of the first protocol may be different than a voltage range of the second protocol. In an embodiment, the voltage range of the first protocol is lower than the voltage range of the second protocol. In another embodiment, the voltage range of the first protocol may be higher than the voltage range of the second protocol. Further, current ranges of the first protocol and the second protocol may also be different. Unlike conventional protocol converter devices which are not able to handle such a scenario, the use of the charging device 102 enables charging the electric vehicle 106 from the EVSE 104 even in this scenario. According to an exemplary embodiment, the first protocol is Bharat DC 001 and the second protocol is Combined Charging System (CCS) Type 2. The voltage range of Bharat DC 001 is 48V – 120V and the voltage range of CCS Type 2 is 200V – 1000V. The current range of Bharat DC 001 is max. 200A and the current range of CCS Type 2 is max. 100A. Though the present disclosure has been explained in the context of Bharat DC 001 and CCS Type 2 protocols, it should be appreciated that the teachings of the present disclosure can be applied to any first and second protocols that have different and/or non-overlapping voltage ranges.
[0024] The EVSE 104 includes a connector corresponding to the second protocol. In an embodiment, the connector of the EVSE 104 corresponds to the CCS Type 2 protocol. For example, the connector of the EVSE 104 includes signaling pins such as Proximity Pilot (PP) and Control Pilot (CP), and power supply pins such as Protective Earth (PE), Neutral (N), Line 1 (L1), Line 2 (L2), Line 3 (L3), DC+ and DC-. The connector of the EVSE 104 is coupled with a socket outlet of the EVSE 104 via a suitable cable. The electric vehicle 106 includes a vehicle inlet having pins corresponding to the first protocol. In an embodiment, the vehicle inlet of the electric vehicle 106 corresponds to the Bharat DC 001 protocol. For example, the vehicle inlet of the electric vehicle 106 includes signaling pins such as Charging Confirmation 1 (CC1), Charging Confirmation 2 (CC2), S+ and S-, power supply pins such as Protective Earth (PE), DC+ and DC-, and auxiliary power supply pins such as A+ and A-.
[0025] The charging device 102 includes an inlet corresponding to the second protocol. In an embodiment, the inlet of the charging device 102 corresponds to the CCS Type 2 protocol and includes a plurality of pins complementary to corresponding pins of the connector of the EVSE 104, for example, PP, CP, PE, N, L1, L2, L3, DC+ and DC-. The charging device 102 further includes a connector corresponding to the first protocol. In an embodiment, the connector of the charging device 102 corresponds to the Bharat DC 001 protocol and includes a plurality of pins complementary to corresponding pins of the vehicle inlet of the electric vehicle 106, namely, CC1, CC2, S+, S-, PE, DC+, DC-, A+ and A-.
[0026] During the operation of the charging device 102, the inlet of the charging device 102 is coupled with the connector of the EVSE 104 and the connector of the charging device 102 is coupled to the vehicle inlet of the electric vehicle 106 via a suitable cable. The charging device 102 provides interoperability between the first protocol of the electric vehicle 106 and the second protocol of the EVSE 104 and facilitates charging of the electric vehicle 106 from the EVSE 104. In an embodiment, the charging device 102 is configured to receive one or more messages as per the second protocol from the EVSE 104, translate the one or more messages into corresponding one or more messages as per the first protocol and send to the electric vehicle 106. Similarly, the charging device 102 is configured to receive one or more messages as per the first protocol from the electric vehicle 106, translate the one or more message into corresponding one or more messages as per the second protocol and send the translated one or more messages to the EVSE 104. The messages to/from the EVSE 104 and the electric vehicle 106 may include one or more of: handshake messages to establish a connection between the EVSE 104 and the electric vehicle 106, charging configuration messages, charging status messages, charging commands, error messages, etc. By interpreting messages in one protocol (the first or the second protocol) and translating them into the other protocol (the second or the first protocol), the charging device 102 ensures seamless communication between the EVSE 104 and the electric vehicle 106.
[0027] The charging device 102 receives from the electric vehicle 106 one or more vehicle charging parameters indicating charging requirements (e.g., one or more of: a demand voltage, a demand current, a demand power, etc.) of the electric vehicle 106. The one or more vehicle charging parameters, e.g., the demand voltage (say 72V), may not match with charging capability, e.g., the voltage range (say 200V – 1000V), of the EVSE 104. The system 100 facilitates charging of the electric vehicle 106 according to the charging requirements of the electric vehicle 106. According to an embodiment, the charging device 102 transmits the charging requirements to the EVSE 104. The EVSE 104 determines that the charging requirements are outside of the charging capabilities, e.g., the voltage range, of the EVSE 104 and switches to a lower power mode. In the lower power mode, the EVSE 104 may provide the demand voltage (72V in this example) at a reduced current. The charging device 102 is configured to transfer the power received from the EVSE 104 to the electric vehicle 106. Thus, the system 100 ensures that the electric vehicle 106 is charged as per the demand voltage even though the charging capability of the EVSE 104 is different than the demand voltage.
[0028] Though in the depicted embodiment, the charging device 102 has been implemented as a separate device, in various embodiments, the functionality of the charging device 102 may be integrated with the EVSE 104 and/or the electric vehicle 106.
[0029] Fig. 2 illustrates schematic block diagrams of the charging device 102, the EVSE 104 and the electric vehicle 106, according to an embodiment of the present disclosure. In the depicted embodiment, the electric vehicle 106 is compliant with the Bharat DC 001 protocol (the first protocol) and the EVSE 104 is compliant with the CCS Type 2 protocol (the second protocol).
[0030] The electric vehicle 106 includes a battery 202, a battery management system (BMS) 204 and a control area network (CAN) controller 206. The battery 202 supplies power to drive the electric vehicle 106 and to various components of the electric vehicle 106 for a proper functioning of the electric vehicle 106. The battery 202 is chargeable using power drawn from the EVSE 104. The battery 202 can be, without limitation, of a Lead–acid battery, a Nickel–metal hydride battery, a molten salt battery, a Lithium-ion battery, a Lithium polymer battery etc.
[0031] The BMS 204 controls functioning of the battery 202 including charging/discharging of the battery 202. The BMS 204 monitors one or more parameters of the battery 202 and controls charging of the battery 202 based upon the monitored one or more parameters. The one or more parameters may include, without limitation, voltage, current, state of charge, temperature, etc. The BMS 204 is communicatively coupled with the CAN controller 206. The BMS 204 sends charging requirements of the electric vehicle 106 to the CAN controller 206. The charging requirements may include one or more of: a voltage range, a current range, a demand voltage, a demand current, etc. The voltage range and the current range may indicate acceptable range of voltages and currents for the electric vehicle 106. The demand voltage and the demand current may indicate a voltage and current required by the electric vehicle 106. The BMS 204 also sends real-time charging status of the battery 202 to the CAN controller 206.
[0032] The CAN controller 206 is configured to handle overall communication to and from the electric vehicle 106 during the charging of the electric vehicle 106. Functions of the CAN controller 206 include communication protocol handling, authentication, authorization, charging parameter configuration, data exchange, error handling, billing and payment handling, fault handling, etc. The CAN controller 206 sends/receives messages/responses associated with different functionalities of the CAN controller 206. For example, the CAN controller 206 communicates the charging requirements of the electric vehicle 106 using an appropriate message, for example, BCL message. In an embodiment, the CAN controller 206 communicates over a CAN interface according to the Bharat DC 001 protocol.
[0033] The EVSE 104 includes a rectifier 208, a power control unit 210 and a supply equipment communication controller (SECC) 212. The rectifier 208 receives an AC power from an input (not shown) and converts the AC power into a DC power. The input may be a grid supply, a solar power inverter or any other suitable AC power source. The AC power may be single-phase or three-phase. The rectifier 208 may be any suitable rectifier known in the art.
[0034] The power control unit 210 receives the rectified DC power from the rectifier 208. The power control unit 210 controls power provided by the EVSE 104. In an embodiment, the power control unit 210 outputs DC power based upon charging capability (voltage range, current range, power capacity, etc.) of the EVSE 104 and the charging requirements of the electric vehicle 106. The power control unit 210 receives the charging requirements of the electric vehicle 106 from the SECC 212. According to an embodiment, the power control unit 210 controls the charging capability of the EVSE 104. For example, the power control unit 210 may set an operating mode based upon the charging requirements of the electric vehicle as received from the charging device 102 as explained later. The power control unit 210 provides the output DC power according the operating mode. The output DC power is provided at the DC+ and DC- pins of the connector of the EVSE 104. The power control unit 210 includes circuitry (e.g., one or more of: Buck converter, Boost converter, Buck-Booth converter, switches, and the like) capable of receiving the rectified DC power as input and providing the output DC power as output according to the operating mode. The power control unit 210 may also include a processing unit (e.g., a microcontroller), a memory, etc. for implementing executing various functions of the power control unit 210 (e.g., setting the operating mode according to the demand voltage as explained later). Though the depicted embodiment shows that the EVSE 104 provides the DC power, the teachings of the present disclosure can also be applied to an EVSE providing AC power.
[0035] The SECC 212 is configured to handle overall communication to and from the EVSE 104 during the charging of the electric vehicle 106. Functions of the SECC 212 include communication protocol handling, authentication, authorization, charging parameter configuration, data exchange, error handling, billing and payment handling, fault handling, etc. The SECC 212 sends/receives messages/responses associated with different functionalities of the SECC 212. For example, the SECC 212 receives the charging requirements of the electric vehicle 106 and forwards the charging requirements to the power control unit 210. In an embodiment, the SECC 212 communicates over a PLC interface according to the CCS Type 2 protocol.
[0036] The EVSE 104 may also include an interlock circuit (not shown). The interlock circuit ensures that the electric vehicle 106 and/or the charging device 102 is not disconnected from the EVSE 104 during the charging of the electric vehicle 106. The EVSE 104 also includes a display (not shown) to present various information associated with the charging of the electric vehicle 106. In an exemplary embodiment, the display presents one or more of: the demand voltage, the demand current, a charging voltage, a charging current, an initial SOC of the battery 202, a current SOC of the battery 202, output power, energy consumption, charging duration, etc.
[0037] The charging device 102 includes a communication unit 216, a control unit 218 and a power unit 220, according to an embodiment.
[0038] The communication unit 216 is communicatively coupled with the SECC 212 and the CAN controller 206. The communication unit 216 communicates with the SECC 212 over a communication interface according to the second protocol (e.g., the PLC interface in the CCS-Type 2 protocol). The communication unit 216 communicates with the CAN controller 206 over a communication interface according to the first protocol (e.g., the CAN interface in the Bharat DC 001 protocol). The communication unit 216 receives messages from and sends messages to the SECC 212 according to the CCS Type 2 protocol. The communication unit 216 receives message from and sends messages to the CAN controller 206 according to the Bharat DC 001 protocol.
[0039] The communication unit 216 is configured to detect a protocol associated with the EVSE 104 (i.e., the second protocol). Similarly, the communication unit 216 may be configured to detect a protocol associated with the electric vehicle 106 (i.e., the first protocol).
[0040] In an embodiment, the communication unit 216 receives signals corresponding to a message from the SECC 212 according to the second protocol (e.g., the CCS Type 2 protocol) over the PLC interface. The communication unit 216 demodulates the signal and recognizes a bit sequence present in the demodulated signal as per the second protocol. The communication unit 216 sends the bit sequence to the control unit 218.
[0041] The control unit 218 is configured to identify a header and a payload of the message from the bit sequence. The control unit 218 is configured to identify the message in the second protocol based upon the header. The control unit 218 determines a corresponding message (hereinafter, a translated message) in the first protocol (e.g., the Bharat DC 001 protocol) using, for example, a mapping between each message in the second protocol and a corresponding message in the first protocol. Such mapping may be stored, for example, as a lookup table. An exemplary look-up table is provided later. The control unit 218 translates the header and the payload of the message in the second protocol into a corresponding translated header and translated payload of the translated message in the first protocol. The control unit 218 forms one or more data packets corresponding to the translated header and the translated payload and sends the one or more data packets to the communication unit 216 for transmitting the one or more data packets to the CAN controller 206.
[0042] The communication unit 216 converts the one or more data packets into a corresponding bit sequence, which are then modulated according to a modulation scheme of the first protocol to generate signals compliant with the first protocol. The communication unit 216 sends the signals to the CAN controller 206 over the CAN interface.
[0043] A message received from the CAN controller 206 as per the first protocol is similarly translated into a message as per the second protocol and sent to the SECC 212, and is not repeated for reasons of brevity. Thus, the control unit 218, together with the communication unit 216, ensures seamless communication between the EVSE 104 and the electric vehicle 106 despite the difference between the protocols followed by the EVSE 104 and the electric vehicle 106.
[0044] The control unit 218 and the power control unit 210 provided in the EVSE 104 work in tandem and control charging of the electric vehicle 106 as per the charging requirements provided by the electric vehicle 106. In an embodiment, the control unit 218 receives the charging requirements from the electric vehicle 106 in one or more messages from the electric vehicle 106. In an exemplary implementation, the BMS 204 sends the charging requirements to the control unit 218 via the CAN controller 206 using the BCP or BCL message of the Bharat DC 001 protocol. The control unit 218 identifies the charging requirements by analyzing the payload of the message. In an embodiment, the charging requirements include a demand voltage and a demand current. The demand voltage may be outside of the voltage range supported by the EVSE 104. The demand voltage is within the voltage range of the first protocol associated with the electric vehicle 106. In an example implementation, the demand voltage may be between 48V - 120V. The actual demand voltage may be determined according to the current status of the battery 202.
[0045] According to an embodiment, the control unit 218 communicates the charging requirements, for example, the demand voltage of 72V, to the EVSE 104 to using an appropriate message according to the second protocol (e.g., Current Demand Request message of CCS Type 2 protocol). The power control unit 210 receives the charging requirements via the SECC 212 as described earlier. The power control unit 210 checks the demand voltage against a voltage range of the EVSE 104. The voltage range of the EVSE 104 may be defined by a minimum voltage and a maximum voltage. When the demand voltage is less than the minimum voltage of the voltage range of the EVSE 104, the power control unit 210 switches to a low power mode. The power control unit 210 outputs a power signal having the demand voltage (e.g., 72V) at DC+ and DC- pins of the EVSE 104 according to the low power mode. In the low power mode, the power control unit 210 may provide the power signal at a current determined according to voltage-current characteristics of the EVSE 104. The control unit 218 controls the power unit 220 to transfer the power at input DC+ and DC- pins to output DC+ and DC- pins of the charging device 102, which are coupled to the DC+ and DC- pins of the battery 202. The control unit 218 also closes switches 222 and 224 to complete the connection.
[0046] Optionally or in addition, the control unit 218 may be configured to perform safety and reliability checks throughout the charging procedure. For example, the control unit 218 may perform one or more checks to ensure accurate translation between the first and the second protocols. The control unit 218 may also check voltage and current alignment as per the first and the second protocols. The control unit 218 may dynamically adjust protocol-specific parameters to ensure consistent and reliable communication. The protocol specific parameters may include, without limitation, the charging voltage provided to the electric vehicle 106, and the charging current provided to the electric vehicle 106. The control unit 218 may monitor the authentication procedure to ensure that safety features, such as overcurrent protection, insulation monitoring are aligned with respective requirements of the first and the second protocols.
[0047] According to an embodiment, the communication unit 216, the control unit 218 and the power unit 220 may be powered by auxiliary power drawn from the battery 202, for example, via the A+ and A- pins, so that no external power supply may be required for the operation of the charging device 102. In such a case, the charging device 102 may include an auxiliary power circuit (e.g., a DC-DC Buck converter). The auxiliary power circuit is configured to receive via at least one pin (e.g., the A+ and A- pins), auxiliary power from the electric vehicle 106 and generate at least one power supply signal having a pre-defined voltage at a pre-defined current (e.g., 12V and 3A) based at least upon the auxiliary power. The at least one power supply signal is provided to various components of one or more of: the communication unit 216, the control unit 218 and the power unit 220.
[0048] Fig. 3 illustrates a schematic block diagram of the communication unit 216 according to an embodiment. The communication unit 216 includes a first interface circuit 302, a second interface circuit 304, a protocol analysis module 306, a bit sequence recognition module 308, a signal conditioning circuit 310, a second processor 312 and a second memory 314.
[0049] The first interface circuit 302 is configured to transmit and receive signals to and from the electric vehicle 106 as per the first protocol. For example, the first interface circuit 302 is communicatively coupled to the CAN controller 206 via the CAN interface. For example, the first interface circuit 302 is coupled to the CAN controller 206 via the pins CC1, CC2, S+ (or CAN-H) and S- (or CAN-L) of the connector of the charging device 102 and the corresponding pins CC1, CC2, CAN-H and CAN-L of the vehicle inlet of the electric vehicle 106. The first interface circuit 302 includes suitable circuitry, for example, a modulator, a demodulator, a transmitter, a receiver, an analog to digital converter, a digital to analog converter, etc. for sending and receiving signals to and from the CAN controller 206 over the CAN interface as per the first protocol (e.g., the Bharat DC 001 protocol).
[0050] The second interface circuit 304 is configured to transmit and receive signals to and from the EVSE 104 as per the second protocol. For example, the second interface circuit 304 is communicatively coupled to the SECC 212 via the PLC interface. For example, the second interface circuit 304 is coupled to the SECC 212 via the pins CP, PP and PE of the inlet of the charging device 102 and the corresponding pins CP, PP and PE of the connector of the EVSE 104. The second interface circuit 304 includes suitable circuitry, for example, a modulator, a demodulator, a transmitter, a receiver, an analog to digital converter, a digital to analog converter, etc. for sending and receiving signals to and from the SECC 212 over the PLC interface as per the second protocol (e.g., the CCS Type protocol).
[0051] The protocol analysis module 306 is communicatively coupled to the first interface circuit 302 and the second interface circuit 304). The protocol analysis module 306 is configured to detect the first protocol and/or the second protocol based at least on the signals received by the corresponding interface circuit (e.g., the first interface circuit 302 and the second interface circuit 304, respectively). In an embodiment, the protocol analysis module 306 analyzes signals received by the second interface circuit 304 to identify patterns and characteristics associated with the second protocol (e.g., the CCS Type 2 protocol). For example, the protocol analysis module 306 may perform one or more of: frequency analysis, amplitude analysis, voltage pattern analysis, current pattern analysis, etc. The protocol analysis module 306 may also implement any suitable protocol analysis algorithm to detect the second protocol. Upon determining that the signals received by the second interface circuit 304 match the patterns and characteristics associated with the second protocol, the protocol analysis module 306 determines the presence of the second protocol. Similarly, the protocol analysis module 306 analyzes signals received by the first interface circuit 302 to identify the first protocol (e.g., the Bharat DC 001 protocol).
[0052] In an embodiment, the first interface circuit 302 receives signals corresponding to a message (hereinafter, a first message) from the electric vehicle 106 according to the first protocol. The first interface circuit 302 demodulates the signals and coverts into digital signals. The first message may be any message (a request or a response) that is sent by the electric vehicle 106 addressed to the EVSE 104 during various stages of a charging procedure defined as per the specification of the first protocol.
[0053] The bit sequence recognition module 308, communicatively coupled to the first interface circuit 302, is configured to identify a sequence of bits from the digital signals. The bit sequence recognition module 308 sends the sequence of bits (corresponding to the first message) to the control unit 218 (or a module thereof).
[0054] The control unit 218 receives the sequence of bits corresponding to the first message. The control unit 218 translates the first message in the first protocol into a corresponding message (hereinafter, a translated first message) compliant with the second protocol (e.g., the CCS Type 2 protocol) for delivering it to the EVSE 104. The translation of the first message as per the first protocol into the translated first message as per the second protocol is explained later.
[0055] In an embodiment, the signal conditioning circuit 310, communicatively coupled to the control unit 218, receives the translated first message (e.g., one or more data packets of the translated first message) from the control unit 218 (or a module thereof). The signal conditioning circuit 310 is configured to convert the translated first message into corresponding analog signals as per requirements of the second protocol (e.g., the CCS Type 2 protocol). For example, the signal conditioning circuit 310 aligns voltage and/or current level, signaling rate, or any other communication parameters (e.g., guard intervals, markers for the header, etc.) required by the second protocol. In an embodiment, the signal conditioning circuit 310 performs the signal conditioning as instructed by the control unit 218 (or a module thereof).
[0056] The second interface circuit 304 is communicatively coupled to the signal conditioning circuit 310 and receives the analog signals corresponding to the translated first message from the signal conditioning circuit 310. The second interface circuit 304 modulates the analog signals and transmits the translated first message as per the second protocol (e.g., the CCS Type 2 protocol) to the SECC 212 over the PLC interface.
[0057] In an embodiment, the second interface circuit 304 receives signals corresponding to a message (hereinafter, a second message) from the EVSE 104 according to the second protocol. The second interface circuit 304 demodulates the signals and converts into digital signals. The second message may be any message (a request or a response) that is sent by the EVSE 104 addressed to the electric vehicle 106 during various stages of a charging procedure defined as per the specification of the second protocol.
[0058] The bit sequence recognition module 308, communicatively coupled to the second interface circuit 304, is configured to identify a sequence of bits from the digital signal according to the second protocol. The bit sequence recognition module 308 sends the sequence of bits (corresponding to the second message) to the control unit 218 (or a module thereof).
[0059] The control unit 218 receives the sequence of bits corresponding to the second message. The control unit 218 translates the second message in the second protocol into a corresponding message (hereinafter, a translated second message) compliant with the first protocol (e.g., the Bharat DC 001 protocol) for delivering it to the electric vehicle 106. The translation of the second message in the second protocol into the translated second message in the first protocol is explained later.
[0060] In an embodiment, the signal conditioning circuit 310 receives the translated second message (e.g., one or more data packets of the translated second message) from the control unit 218 (or a module thereof). The signal conditioning circuit 310 is configured to convert the translated second message into corresponding analog signals as per requirements of the first protocol (e.g., the Bharat DC 001). For example, the signal conditioning circuit 310 aligns voltage and/or current level, signaling rate, or any other communication parameters (e.g., guard intervals, markers for the header, etc.) required by the first protocol. In an embodiment, the signal conditioning circuit 310 performs the signal conditioning as instructed by the control unit 218 (or a module thereof).
[0061] The first interface circuit 302 is communicatively coupled to the signal conditioning circuit 310 and receives the analog signals corresponding to the translated second message from the signal conditioning circuit 310. The first interface circuit 302 modulates the analog signals and transmits the translated second message as per the first protocol (e.g., the Bharat DC 001 protocol) to the CAN controller 206 over the CAN interface. Thus, messages from the EVSE 104 are seamlessly delivered to the electric vehicle 106 and vice versa even though the charging protocols of the EVSE 104 and the electric vehicle 106 different.
[0062] In an embodiment, the protocol analysis module 306 and the bit sequence recognition module 308 are stored in the second memory 314. The second memory 314 may be a read only memory, a random access memory, a flash memory, a hard disk, or any other suitable computer readable data storage medium. In an example implementation, the protocol analysis module 306 and the bit sequence recognition module 308 are stored as firmware. According to an embodiment, the protocol analysis module 306 and the bit sequence recognition module 308 are executed by the second processor 312. The second processor 312 may be a microprocessor, a microcontroller, an application-specific processor, a general-purpose computer, etc. or any other processing unit capable of executing computer-readable instructions.
[0063] Fig. 4 illustrates a schematic block diagram of the control unit 218 according to an embodiment. The control unit 218 includes a protocol translation module 402, a power control module 404, a communication optimization module 406, a Quality of Service (QoS) module 408, an error correction module 410, a first processor 412 and a first memory 414.
[0064] The protocol translation module 402 is configured to translate messages from one protocol (e.g., the first protocol) into the other protocol (e.g., the second protocol) and vice versa. In an embodiment, the protocol translation module 402 is configured to receive the first message from the electric vehicle 106. The first message is according to the first protocol (e.g., the Bharat DC 001 protocol). The first message includes a first header and a first payload. The protocol translation module 402 is configured to form the corresponding translated first message according to the second protocol (e.g., the CCS Type 2 protocol). The translated first message includes a translated first header and a translated first payload. The translated first header corresponds to the first header and is according to the second protocol. Similarly, the translated first payload corresponds to the first payload and is according to the second protocol. An exemplary implementation of how the protocol translation module 402 translates the first message into the translated first message is explained below.
[0065] In an embodiment, the protocol translation module 402 receives the first message, for example, in the form of the bit sequence corresponding to the first message from the bit sequence recognition module 308. The protocol translation module 402 is communicatively coupled to the bit sequence recognition module 308. The protocol translation module 402 is configured to determine the first header from the bit sequence using, for example, information about header structure (e.g., number of bits of a header, one or more marker bits indicating a start of a header, etc.) of various messages defined in the first protocol. The information about the header structure may be in the form of a lookup table stored in the first memory 414. The protocol translation module 402 is configured to analyze the first header and identify the first payload based at least upon the first header (for example, the first header may include one or more bits indicating a length of the first payload).
[0066] The protocol translation module 402 is configured to identify the first message based upon the first header using, for example, a lookup table representing a correspondence between each message of the first protocol and a corresponding header. The lookup table may be stored in the first memory 414. The protocol translation module 402 analyses the first payload based at least in part upon the first message and the first header and determines information present in the first payload. The protocol translation module 402 may use a mapping between different values of bits in the first payload and a corresponding interpretation to determine the information in the first payload. Such a mapping may be stored in the first memory 414.
[0067] The protocol translation module 402 is configured to identify the translated first message corresponding to the first message. As described earlier, the first message adheres to the first protocol and the translated first message adheres to the second protocol. In an embodiment, the protocol translation module 402 uses a mapping between all messages in the first protocol and corresponding messages in the second protocol (and vice versa) to identify the translated first message. The mapping may be stored in the first memory 414 in the form of a lookup table. An exemplary look-up table including the mapping of messages between the Bharat DC 001 protocol and the CCS Type 2 protocol is given below in Table 1. It should be appreciated that the look-up table below illustrates a few exemplary messages and is not exhaustive.
Bharat DC 001 CCS Type 2
CRM Session Setup Request
BRM Session Setup Response
BCP Charger Parameter Discovery Request
CML Charger Parameter Discovery Request
BCL Current Demand Request
CCS Power Delivery
BST Session Stop
CST Session Stop
Table 1
[0068] The protocol translation module 402 generates the translated first header. The translated first header of the translated first message has a format and packet structure compliant with the second protocol. The protocol translation module 402 further converts the information (in the first payload of the first message) into the translated first payload of the translated first message according to the format and packet structure of the payload compliant with the second protocol. The protocol translation module 402 forms one or more data packets corresponding to the translated first message.
[0069] The protocol translation module 402 is configured to transmit the translated first message to the EVSE 104. For example, the protocol translation module 402 sends the translated first message including the translated first header and the translated first payload to the signal conditioning circuit 310, which in turn transmits the translated first message to the SECC 212 over the communication interface associated with the second protocol via the second interface circuit 304 as explained earlier.
[0070] Similarly, in an embodiment, the protocol translation module 402 is configured to receive the second message from the EVSE 104. The second message is according to the second protocol (e.g., the CCS Type 2 protocol). The second message includes a second header and a second payload. The protocol translation module 402 is configured to form the corresponding translated second message according to the first protocol (e.g., the Bharat DC 001 protocol). The translated second message includes a translated second header and a translated second payload. The translated second header corresponds to the second header and is according to the first protocol. Similarly, the translated second payload corresponds to the second payload and is according to the first protocol.
[0071] In an embodiment, the protocol translation module 402 receives the second message in the form of the bit sequence corresponding to the second message from the bit sequence recognition module 308. The protocol translation module 402 is configured to determine the second header from the bit sequence using, for example, information about header structure (e.g., number of bits of a header, one or more marker bits indicating a start of a header, etc.) of various messages defined in the second protocol. The information about the header structure may be in the form of a lookup table stored in the first memory 414. The protocol translation module 402 is configured to analyze the second header and identify the second payload based at least upon the second header (for example, the second header may include one or more bits indicating a length of the second payload).
[0072] The protocol translation module 402 is configured to identify the second message based upon the second header using, for example, a lookup table representing a correspondence between each message of the second protocol and a corresponding header. The lookup table may be stored in the first memory 414. The protocol translation module 402 analyses the second payload based at least in part upon the second message and the second header and determines information present in the second payload. The protocol translation module 402 may use a mapping between different values of bits in the second payload and a corresponding interpretation to determine the information in the second payload. Such a mapping may be stored in the first memory 414.
[0073] The protocol translation module 402 is configured to identify the translated second message corresponding to the second message. As described earlier, the second message adheres to the second protocol and the translated second message adheres to the first protocol. In an embodiment, the protocol translation module 402 uses a mapping between all messages in the first protocol and corresponding messages in the second protocol (and vice versa) to identify the translated second message. The mapping may be stored in the first memory 414 in the form of a lookup table. An exemplary look-up table is given earlier in Table 1.
[0074] The protocol translation module 402 generates the translated second header. The translated second header of the translated second message has a format and packet structure compliant with the first protocol. The protocol translation module 402 further converts the information (in the second payload of the second message) into the translated second payload of the translated second message according to the format and packet structure of the payload compliant with the first protocol. The protocol translation module 402 forms one or more data packets corresponding to the translated second message.
[0075] The protocol translation module 402 is configured to transmit the translated second message to the electric vehicle 106. For example, the protocol translation module 402 sends the translated second message including the translated second header and the translated second payload to the signal conditioning circuit 310, which in turn transmits the translated second message to the CAN controller 206 over the communication interface associated with the first protocol via the first interface circuit 302 as explained earlier.
[0076] The power control module 404 is communicatively coupled with the protocol translation module 402. The power control module 404 is configured to control a charging power (a charging voltage and a charging current) provided to the battery 202 based upon charging requirements provided by the BMS 204 and charging capabilities of the EVSE 104 provided by the power control unit 210 of the EVSE 104. The charging requirements may be provided by the BMS 204 in a suitable message (or messages) according to the first protocol. In an exemplary implementation, the BMS 204 provides the charging requirements in a BCP message or a BCL message of the Bharat DC 001 protocol. The charging requirements includes one or more of: a demand voltage, a demand current and a demand power. The charging capabilities may be provided in a suitable message according to the second protocol. In an exemplary implementation, the power control unit 210 provides the charging capabilities in a Charge Parameter Discovery Response message of the CCS Type 2 protocol. The charging capabilities include one or more of: a minimum voltage, a maximum voltage, a minimum current, a maximum current, etc.
[0077] According to an embodiment, the protocol translation module 402 is configured to receive a charging request message (e.g., the BCP or BCL message) from the electric vehicle 106. The charging request message is according to the first protocol associated with the electric vehicle 106. The charging request message includes the demand voltage and the demand current. In response to the protocol translation module 402 determining that the charging request message is received from the electric vehicle 106, the protocol translation module 402 is configured to send the charging requirements and/or the charging request message to the power control module 404. Similarly, in response to the protocol translation module 402 determining that the message having the charging capabilities of the EVSE 104 is received, the protocol translation module 402 is configured to send the charging capabilities and/or the message having the charging capabilities to the power control module 404. The power control module 404 is configured to receive the demand voltage and the demand current from the protocol translation module 402.
[0078] Further, the power control module 404 communicates the demand voltage to the EVSE 104. In an embodiment, the power control module 404 is configured to send a control message to the protocol translation module 402, causing the protocol translation module 402 to transmit the demand voltage to the EVSE 104. The control message may include the demand voltage. In response to receiving the control message, the protocol translation module 402 is configured to form a message (hereinafter, a translated charging request message) according to the second protocol. The translated charging request message corresponds to the charging request message according to the first protocol. This is done in a similar manner as described earlier. The translated charging request message includes at least the demand voltage. The protocol translation module 402 may also set a parameter indicating that the power control unit 210 may deliver the demand voltage at a maximum possible current according to voltage-current characteristics of the EVSE 104. The protocol translation module 402 is configured to transmit the translated charging request message to the EVSE 104 (e.g., to the power control unit 210 of the EVSE 104). In an exemplary implementation, the protocol translation module 402 transmits the demand voltage to the EVSE 104 using the Current Demand Request message as per the CCS Type 2 protocol. The protocol translation module 402 sets the voltage parameter in the Current Demand Request message to be 72V. In an embodiment, the demand voltage may be represented by an appropriate duty cycle (e.g., 5%) in the payload of the Current Demand Request message. The signal conditioning circuit 310 may include appropriate circuitry to generate a PWM signal with the appropriate duty cycle based upon the demand voltage.
[0079] The power control unit 210 is communicatively coupled to the protocol translation module 402 via the SECC 212. The Current Demand Request message is routed to the power control unit 210 in a similar manner as explained earlier. The power control unit 210 is configured to receive, via the SECC 212, the demand voltage in the translated charging request message. In an embodiment, the power control unit 210 is configured to compare the demand voltage with the voltage range of the EVSE 104. The voltage range of the EVSE 104 may be defined by the minimum voltage and the maximum voltage that can be provided by the EVSE 104. The power control unit 210 may determine that the charging requirements do not match with the charging capabilities. In an embodiment, the power control unit 210 is configured to determine that the demand voltage (e.g., 72V) is less than the minimum voltage (e.g., 200V) of the voltage range of the EVSE 104. In response to determining that the demand voltage is less than the minimum voltage, the power control unit 210 is configured to set an operating mode to a low power mode. The low power mode may enable the power control unit 210 to output a voltage below the minimum voltage but at a reduced current as determined by the voltage-current characteristics of the EVSE 104. The power control unit 210 is further configured to output a power signal having the demand voltage (e.g., 72V) at maximum possible current (e.g., 60A) at the DC+ and DC- pins of the EVSE 104 according to the low power mode.
[0080] The power control module 404 is configured to control the power unit 220 to transfer the received power from the DC+ and DC- pins at the inlet of the charging device 102 to the DC+ and DC- pins of the inlet of the electric vehicle 106 via the connector of the charging device 102. In an embodiment, the power control module 404 is configured generate at least one control signal and send the at least one control signal to the power unit 220. The at least one control signal may be a pulse width modulated (PWM) signal. The power control module 404 may ensure that the timing of the at least one control signal is in sync with the power signal received from the EVSE 104 so that the power unit 220 transfers the power signal appropriately. An embodiment of the power unit 220 is elaborated in Fig. 5. Further, the power control module 404 is configured to close the switches 222 and 224 to complete the connection. The switches 222 and 224 may be high power semiconductor switches, high power relays, etc. Thus, the power control module 404 and the power control unit 210 facilitate charging of the electric vehicle 106 as per its charging requirements even if the charging requirements do not match with the charging capabilities of the EVSE 104.
[0081] The communication optimization module 406 may be configured to provide (for example, in real-time) various information associated with the charging of the electric vehicle 106 to the EVSE 104 using appropriate one or more messages as per the second protocol. In an exemplary embodiment, the information may include one or more of: the demand voltage, the demand current, a charging voltage, a charging current, an initial SOC of the battery 202, a current SOC of the battery 202, output power, energy consumption, charging duration, etc. The communication optimization module 406 may receive the information from the BMS 204. The BMS 204 may send such information via appropriate one or more status messages of the first protocol (e.g., the Bharat DC 001 protocol) which are translated by the protocol translation module 402 and provided to the communication optimization module 406. The EVSE 104 may display the information on the display of the EVSE 104.
[0082] Optionally or in addition, the communication optimization module 406 is configured to optimize communication between the EVSE 104 and the electric vehicle 106. This ensures optimal data transfer rates and efficient protocol translation. In an embodiment, the communication optimization module 406 is configured to adjust a signaling rate and/or timing of the messages exchanged between the EVSE 104 and the electric vehicle 106. This may be done by taking into account time required for translating the messages between the first protocol and the second protocol. In an embodiment, once the connection is established between the electric vehicle 106 and the EVSE 104, the communication optimization module 406 sends the information associated with the charging of the electric vehicle 106 to the SECC 212, while preventing status information from the EVSE 104 to be displayed on the display of the EVSE 104 so that the information displayed on the display of the EVSE 104 is in sync with the real-time status of the battery 202. Once the charging process is complete, the communication optimization module 406 may send the status information from the EVSE 104 to the display.
[0083] The Quality of Service (QoS) module 408 is configured to maintain QoS as per requirements of both the first protocol and the second protocol. For example, the QoS module 408 may prioritize protocol translation of one or more critical messages. Examples of such critical messages may be, without limitation, authentication, safety messages, protocol-specific control messages. This ensures timely and reliable data transfer.
[0084] The error correction module 410 is configured to handle one or more errors occurring during the overall charging procedure. The error correction module 410 may detect errors in the data packets corresponding to the messages between the EVSE 104 and the electric vehicle 106 using any suitable techniques known in the art, e.g., checksum, cyclic redundancy check, parity checking, hash function, etc. The error correction module 410 may localize the errors by analyzing the data packets and/or signals associated with the messages. The error correction module 410 may implement one or more error correction techniques, e.g., forward error correction, interleaving, etc., to fix the errors. The error correction module 410 may also implement retry mechanisms, e.g., the error correction module 410 may request retransmission of one or more messages that may have been received erroneously. A feedback loop may be implemented to provide information about success or failure of the error correction. For critical or sensitive messages, the error correction module 410 may have additional mitigation techniques, such as, redundancy or diversity of messages, real-time monitoring of such messages and so on. In an embodiment, the error correction module 410 may adapt error handling mechanism based upon severity and/or frequency of the errors.
[0085] In an embodiment, the protocol translation module 402, the power control module 404, the communication optimization module 406, the QoS module 408 and the error correction module 410 are executed by the first processor 412. The first processor 412 may be a microprocessor, a microcomputer, an application-specific processor, a general-purpose computer, etc. or any other processing unit capable of executing computer-readable instructions. The first processor 412 may be the same as or different than the second processor 312. In an embodiment, the protocol translation module 402, the power control module 404, the communication optimization module 406, the QoS module 408 and the error correction module 410 are embedded in the first memory 414. The first memory 414 may be a read only memory, a random access memory, a flash memory, a hard disk, or any other suitable computer readable data storage medium. The first memory 414 may be the same as or different than the second memory 314. In an embodiment, the protocol translation module 402, the power control module 404, the communication optimization module 406, the QoS module 408 and the error correction module 410 are implemented as firmware.
[0086] It should be appreciated that one or more modules of the communication unit 216 may be implemented in the control unit 218 and vice versa based upon requirements.
[0087] Fig. 5 depicts a schematic block diagram of the power unit 220, according to an embodiment. The power unit 220 provides power to the battery 202. The power unit 220 is communicatively coupled to the power control module 404 and is configured to receive the at least one control signal. The power unit 220 includes inputs 506a and 506b coupled to the EVSE 104, e.g., to the D+ and D- pins of the EVSE 104 via the respective pins of the inlet of the charging device 102. The power unit 220 includes outputs 508a and 508b coupled to the electric vehicle 106, e.g., to the D+ and D- pins of the inlet of the electric vehicle 106 via the respective pins of the connector of the charging device 102. The power unit 220 is configured to receive the power signal having the demand voltage from the EVSE 104 at the inputs 506a and 506b and is configured to transfer the power signal to the outputs 508a and 508b based upon the at least one control signal. The power signal is then delivered to the electric vehicle 106.
[0088] In an embodiment, the power unit 220 includes a switching circuit 502 and a driver circuit 504. The switching circuit 502 is coupled to the inputs 506a and 506b and to the outputs 508a and 508b. Thus, the received power signal is provided as the input to the switching circuit 502. The switching circuit 502 is configured to transfer the power signal at the inputs 506a and 506b to the outputs 508a and 508b based upon the at least one control signal. The switching circuit 502 may be opened or closed depending upon the at least one control signal to transfer the power signal to the outputs 508a and 508b. The switching circuit 502 is coupled to the at least one control signal via the driver circuit 504. The driver circuit 504 includes at least one output coupled to the switching circuit 502. The driver circuit 504 includes at least one input coupled to the at least one control signal output by the power control module 404 of the control unit 218. The driver circuit 504 drives the switching circuit 502 based upon the at least one control signal. The driver circuit 504 also provides isolation between different voltage levels of the switching circuit 502 and the control unit 218.
[0089] The switching circuit 502 may be any high-power switching circuit capable of transferring a power signal received at an input to an output. In an embodiment, the switching circuit 502 includes a plurality of high-power semiconductor switching elements. The plurality of high-power semiconductor switching elements are switched ON or OFF based upon a respective output of the at least one output of the driver circuit 504.
[0090] Each of the plurality of high-power semiconductor switching elements may be an Insulated Gate Bipolar Transistor (IGBT), a power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) or a thyristor. In an example implementation, the plurality of high-power semiconductor switching elements include a plurality of IGBTs. The driver circuit 504 may be an opto-coupler circuit. The at least one output of the driver circuit 504 is coupled to a gate terminal of the respective IGBT. Based upon the at least one control signal, one or more IGBTs of the plurality of IGBTs are switched ON to transfer the power at the inputs 506a and 506b to the outputs 508a and 508b.
[0091] In an embodiment, the outputs 508a and 508b may also be coupled to the control unit 218 via appropriate circuitry (not shown). The control unit 218 (or the power control module 404 of the control unit 218) monitors the power signal at the outputs 508a and 508b, determines whether there are any deviations from the desired charging power to be supplied to the electric vehicle 106 and adjusts the at least one control signal accordingly. Thus, a feedback loop is implemented so that appropriate correction can be performed.
[0092] Though the power unit 220 illustrated in Fig. 5 corresponds to the EVSE 104 providing the DC power, it should be appreciated that the power unit 220 can be adapted to receiving AC power from the EVSE 104, wherein the power signal may be an AC power signal having the demand voltage, without deviating from the scope of the present disclosure. In this case, the power unit 220 may include AC-DC converter circuitry coupled to the inputs 506a and 506b, and the switching circuit 502. The AC-DC converter circuitry is configured to convert the AC power signal at the inputs 506a and 506b, to a DC power signal having the demand voltage and provide the DC power signal to the switching circuit 502. In an embodiment, the AC-DC converter circuitry includes a rectifier (a single phase or three phase depending upon whether the EVSE 104 provides single phase or three phase power), a power factor correction circuit, an isolation circuit, etc. to convert the AC power signal to the DC power signal provided as input to the switching circuit 502.
[0093] Fig. 6 depicts a flowchart of a method 600 for charging an electric vehicle 106, in accordance with an embodiment of the present disclosure. Though the steps of the method 600 have been described below as performed by respective modules of the communication unit 216 and/or the control unit 218, they may be performed by other modules of the communication unit 216 and/or the control unit 218 without deviating from the scope of the present disclosure.
[0094] At step 602, a connection of the EVSE 104 and the electric vehicle 106 with the charging device 102 is detected. In an embodiment, the second interface circuit 304 may detect whether the EVSE 104 is connected based upon a signal level at one or more of the CP and PP pins at the inlet of the charging device 102. For example, signals at the PP and/or CP pins may be driven high or low when the connector of the EVSE 104 is plugged into the inlet of the charging device 102. Similarly, the first interface circuit 302 may detect that the electric vehicle 106 is connected based upon a signal level at one or more of CC1, S+ and S- pins at the connector of the charging device 102. For example, signals at the CC1, S+ and S- pins may be driven high or low when the connector of the charging device 102 is plugged into the inlet of the electric vehicle 106.
[0095] At step 604, protocols associated with the EVSE 104 and the electric vehicle 106 are identified. The protocol analysis module 306 identifies the protocols associated with the EVSE 104 and the electric vehicle 106 using one or more of the signal analysis and protocol analysis algorithm as described earlier. In an embodiment, the protocol analysis module 306 may identify that the electric vehicle 106 complies with the first protocol and the EVSE 104 complies with the second protocol, which is different than the first protocol. In an exemplary implementation, the first protocol is the Bharat DC 001 protocol and the second protocol is the CCS Type 2 protocol.
[0096] At step 606, a communication link between the EVSE 104 and the electric vehicle 106 is established using the respective protocols. In an embodiment, the EVSE 104 and the electric vehicle 106 may exchange a plurality of messages with each other to establish the communication link as per requirements of the respective protocols. The first interface circuit 302 and the second interface circuit 304 receive the messages over respective communication interfaces and forward the received messages to the protocol translation module 402. The protocol translation module 402 translates the messages into the appropriate protocol. The translated messages are delivered to the EVSE 104 or the electric vehicle 106 as appropriate. For example, the protocol translation module 402 translates messages in the first protocol received from the electric vehicle 106 into corresponding messages in the second protocol and transmits these translated messages to the EVSE 104. Similarly, the protocol translation module 402 translates messages in the second protocol received from the EVSE 104 into corresponding messages in the first protocol and transmits these translated messages to the electric vehicle 106. An embodiment of a method for translating the messages in the first protocol to the second protocol and vice versa is explained in Fig. 7. Thus, the protocol translation module 402 ensures a seamless communication link between the EVSE 104 and the electric vehicle 106 despite the difference between the protocols followed by the EVSE 104 and the electric vehicle 106.
[0097] At step 608, a charging request message is received by the protocol translation module 402 from the electric vehicle 106 according to the first protocol. The charging request message may specify charging requirements of the electric vehicle 106. The charging requirements may include one or more of: a demand voltage, a demand current and a demand power. According to an embodiment, the charging request message includes the demand voltage and the demand current. In an example implementation, the charging requirements may be provided in the BCP message and/or the BCL message as per the Bharat DC 001 protocol. In one example, the demand voltage may be 96V. The charging requirements are sent by the protocol translation module 402 to the power control module 404. The demand voltage and the demand current may be received by the power control module 404 from the protocol translation module 402.
[0098] At step 610, a translated charging request message is transmitted by the protocol translation module 402 to the EVSE 104 according to the second protocol. The translated charging request message in the second protocol corresponds to the charging request message in the first protocol. The protocol translation module 402 determines the translated charging request message in a similar manner as described earlier. The translated charging request message includes the demand voltage. The translated charging request message may also indicate to provide the demand voltage at the maximum possible current. In an exemplary implementation, the protocol translation module 402 sends the charging requirements to EVSE 104 (e.g., to the power control unit 210 of the EVSE 104) using the Current Demand Request message as per the CCS Type 2 protocol. In an embodiment, a control message may be generated by the power control module 404 upon receiving the demand voltage and the demand current. The control message is sent to the protocol translation module 402. The translated charging request message may be transmitted by the protocol translation module 402 in response to receiving the control message. The control message may include the demand voltage.
[0099] At step 612, at least one control signal is generated by the power control module 404. The power control module 404 sends the at least one control signal to the power unit 220. The at least one control signal controls the power unit 220 to provide power to the electric vehicle 106 based upon the power signal provided by the EVSE 104.
[00100] At step 614, the demand voltage in the translated charging request message is received by the power control unit 210 via the SECC 212. The demand voltage is compared with the voltage range of the EVSE 104 by the power control unit 210.
[00101] At step 616, it is determined by the power control unit 210 that the demand voltage is less than the minimum voltage of the voltage range of the EVSE 104. For example, the power control module 404 determines that the demand voltage (e.g., 96V) is lower than the minimum voltage (e.g., 200V).
[00102] In response to determining that the demand voltage is less than the minimum voltage, at step 618, the operating mode is set to the low power mode.
[00103] At step 620, a power signal having the demand voltage is output by the power control unit 210 according to the low power mode. In an embodiment, the power control unit 210 provides the power signal having the demand voltage at the maximum possible current at the DC+ and DC- pins of the EVSE 104. The maximum possible current may be determined by the power control unit 210 based upon one or more factors such as the demand voltage, maximum power that can be delivered by the EVSE 104, safety margin on the possible current to prevent overloading, etc.
[00104] At step 622, the power signal output by the power control unit 210 is received, for example, by the power unit 220 at the inputs 506a and 506b of the power unit 220.
[00105] At step 624, the power signal is transferred by the power unit 220 to the electric vehicle 106 based upon the at least one control signal. For example, the power unit 220 transfers the received power signals at the inputs 506a and 506b to the outputs 508a and 508b based upon the at least one control signal. The power control module 404 may ensure proper timing requirements so that the power unit 220 operates when the power signal is received.
[00106] Fig. 7 depicts a flowchart of a method 700 for translating messages between the EVSE 104 and the electric vehicle 106 compliant with different protocols, in accordance with an embodiment of the present disclosure. In an embodiment, the electric vehicle 106 is compliant with the first protocol (e.g., the Bharat DC 001 protocol) and the EVSE 104 is compliant with the second protocol (e.g., the CCS Type 2 protocol). Though one or more steps of the method 700 below as being performed by various modules of the communication unit 216 and/or the control unit 218, the steps may be performed by other modules of the communication unit 216 and/or of the control unit 218.
[00107] At step 702, a message is received from one of the EVSE 104 and the electric vehicle 106 by the protocol translation module 402 via an appropriate interface unit of the communication unit 216. In an embodiment, a message from the electric vehicle 106 (hereinafter, a first message) is received via the first interface circuit 302 and a message from the EVSE 104 (hereinafter, a second message) is received by the second interface circuit 304. The first message and the second message are according to the first protocol and the second protocol, respectively. The first message includes a first header and a first payload. The second message includes a second header and a second payload.
[00108] According to an embodiment, a protocol associated with the message is identified by the protocol analysis module 306 and a corresponding bit sequence is formed by the bit sequence recognition module 308. The protocol translation module 402 may receive the first message and the second message in the form of corresponding bit sequences from the bit sequence recognition module 308. In an embodiment, the protocol analysis module 306 analyses received signals corresponding to the message and identifies the protocol associated with the message based upon the analysis as explained earlier. In an embodiment, the protocol analysis module 306 may identify that the second message from the EVSE 104 is compliant with the second protocol. Similarly, the protocol analysis module 306 may identify that the first message from the electric vehicle 106 is compliant with the first protocol.
[00109] In an embodiment, the bit sequence corresponding to the first message is formed according to the first protocol and the bit sequence corresponding to the second message is formed according to the second protocol by the bit sequence recognition module 308. The bit sequences are sent by the bit sequence recognition module 308 to the protocol translation module 402.
[00110] At step 704, the message is identified by the protocol translation module 402 based upon the corresponding bit sequence. According to an embodiment, a header and a payload of the message is identified by the protocol translation module 402 based upon the bit sequence as per the identified protocol as explained earlier. In an embodiment, the first header of the first message is identified according to the first protocol and the second header of the second message is identified according to the second protocol. Further, the first payload of the first message is identified based upon the first header. Similarly, the second payload of the second message is identified.
[00111] The message is then identified by the protocol translation module 402 based upon the corresponding header using, for example, a look-up table including a mapping of all messages of the identified protocol and corresponding headers as described earlier. Thus, the first message is identified based upon the first header as per the first protocol and the second message is identified based upon the second header as per the second protocol. Further, the first payload of the first message is analyzed by the protocol translation module 402 and the information in the first payload is determined. Similarly, the second payload of the second message is analyzed by the protocol translation module 402 and the information in the second payload is determined.
[00112] At step 706, a message (hereinafter, a translated message) corresponding to the received message is identified by the protocol translation module 402. The translated message is compliant with a protocol different than the protocol of the received message. In an embodiment, when the first message is received, a translated first message corresponding to the first message is identified by the protocol translation module 402, wherein the translated first message is according to the second protocol. Similarly, in an embodiment, when the second message is received, a translated second message corresponding to the second message is identified by the protocol translation module 402, wherein the translated second message is according to the first protocol. According to an embodiment, the protocol translation module 402 uses a look-up table having a mapping of messages in the first protocol with corresponding messages in the second protocol to identify the translated first message and the translated second message. An exemplary look-up table is illustrated in Table 1 earlier.
[00113] At step 708, the translated message compliant with the other protocol is formed. The translated message includes a translated header and a translated payload. In an embodiment, when the first message is received, the corresponding translated first message is formed by the protocol translation module 402 according to the second protocol. The translated first message includes a translated first header and a translated first payload. The translated first header and the translated first payload correspond to the first header and the first payload, respectively. In an embodiment, the translated first header is formed based upon a packet structure defined for the translated first message according to the second protocol. Further, the translated first payload is formed based upon the information in the first message and the packet structure of the translated first message.
[00114] Similarly, in an embodiment, when the second message is received, the corresponding translated second message is formed by the protocol translation module 402 according to the first protocol. The translated second message includes a translated second header and a translated second payload corresponding to the second header and the second payload, respectively. In an embodiment, the translated second header is formed based upon a packet structure defined for the translated second message according to the first protocol. Further, the translated second payload is formed based upon the information in the second message and the packet structure of the translated second message.
[00115] At step 710, the translated message is transmitted to appropriate one of the EVSE 104 and the electric vehicle 106. According to an embodiment, the translated first message is sent by the protocol translation module 402 to the EVSE 104 via a communication interface associated with the second protocol (e.g., the PLC interface for the CCS Type 2 protocol). Similarly, the translated second message is sent by the protocol translation module to the electric vehicle via a communication interface associated with the first protocol (e.g., the CAN interface for the Bharat DC 001 protocol). In an embodiment, the protocol translation module 402 sends the translated first message and the translated second message to the signal conditioning circuit 310. The signal conditioning circuit 310 may form signals corresponding to the translated first message and the translated second message and condition various parameters of the signals, e.g., a voltage, a current, an amplitude, a frequency, a duty cycle, a modulation, a signaling rate, etc. according to the requirements of the appropriate protocol. The signal conditioning circuit 310 transmits the translated message (the translated first message or the translated second message) via an appropriate interface circuit over an appropriate interface. In an example implementation, the translated first message is sent to the EVSE 104 via the second interface circuit 304 over the PLC interface and the translated second message is sent to the electric vehicle 106 via the first interface circuit 302 over the CAN interface.
[00116] The scope of the invention is only limited by the appended patent claims. 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 teachings of the present invention is/are used. ,CLAIMS:WE CLAIM
1. A system (100) for charging an electric vehicle, the system (100) comprising:
a charging device (102) coupled to an electric vehicle supply equipment (EVSE) (104) and an electric vehicle (106), the charging device (102) comprising:
a. a protocol translation module (402), executed by a first processor (412), configured to
i. receive a charging request message from the electric vehicle (106) according to a first charging protocol associated with the electric vehicle (106), the charging request message comprising a demand voltage; and
ii. transmit a translated charging request message comprising the demand voltage, to the EVSE (104) according to a second charging protocol associated with the EVSE (104);
b. a power control module (404), communicatively coupled to the protocol translation module (402) and executed by the first processor (412), configured to:
i. receive the demand voltage from the protocol translation module (402); and
ii. generate at least one control signal; and
c. a power unit (220) comprising inputs (506a, 506b) coupled to the EVSE (104) and outputs (508a, 508b) coupled to the electric vehicle (106), the power unit (220) configured to:
i. receive the at least one control signal;
ii. receive a power signal having the demand voltage from the EVSE (104) at the inputs (506a, 506b); and
iii. transfer the power signal to the outputs (508a, 508b) based upon the at least one control signal; and
a power control unit (210) provided in the EVSE (104) and communicatively coupled with the protocol translation module (402), the power control unit (210) configured to:
a. receive the demand voltage in translated charging request message;
b. determine that the demand voltage is less than a minimum voltage of a voltage range of the EVSE (104);
c. in response to determining that the demand voltage is less than the minimum voltage, set an operating mode to a low power mode; and
d. output the power signal having the demand voltage according to the low power mode.
2. The system (100) as claimed in claim 1, wherein the first charging protocol is Bharat DC 001 and the second charging protocol is Combined Charging System (CCS) Type 2.
3. The system (100) as claimed in claim 1, wherein the power unit (220) comprises a switching circuit (502) coupled to the inputs (506a, 506b) and the outputs (508a, 508b), the switching circuit (502) configured to transfer the power signal at the inputs (506a, 506b) to the outputs (508a, 508b) based upon the at least one control signal.
4. The system (100) as claimed in claim 3, wherein the power signal is an AC power signal having the demand voltage, wherein the power unit (220) comprises AC-DC converter circuitry coupled to the inputs (506a, 506b) and configured to:
a. convert the AC power signal at the inputs (506a, 506b) to a DC power signal having the demand voltage; and
b. provide the DC power signal to the switching circuit (502).
5. The system (100) as claimed in claim 1, wherein the charging device (102) comprises an auxiliary power circuit configured to:
a. receive, via at least one pin, auxiliary power from the electric vehicle (106); and
b. generate at least one power supply signal having a pre-defined voltage based at least upon the auxiliary power.
6. The system (100) as claimed in claim 1, wherein the charging device (102) comprises:
a. a connector corresponding to the first charging protocol, the connector having a plurality of pins complementary to corresponding pins of a vehicle inlet of the electric vehicle (106); and
b. an inlet corresponding to the second charging protocol, the inlet having a plurality of pins complementary to corresponding pins of a connector of the EVSE (104).
7. The system (100) as claimed in claim 1, wherein the protocol translation module (402) is configured to:
a. receive a first message from the electric vehicle (106) according to the first charging protocol, the first message comprising a first header and a first payload;
b. form a corresponding translated first message according to the second charging protocol, the translated first message comprising a translated first header and a translated first payload;
c. transmit the translated first message to the EVSE (104);
d. receive a second message from the EVSE (104) according to the second charging protocol, the second message comprising a second header and a second payload;
e. form a corresponding translated second message according to the first charging protocol, the translated second message comprising a translated second header and a translated second payload; and
f. transmit the translated second message to the electric vehicle (106).
8. A method for charging an electric vehicle, the method comprising:
a. receiving, by a protocol translation module (402), a charging request message from an electric vehicle (106) according to a first charging protocol associated with the electric vehicle (106), the charging request message comprising a demand voltage;
b. transmitting, by the protocol translation module (402), a translated charging request message comprising the demand voltage, to an electric vehicle supply equipment (EVSE) (104) according to a second charging protocol associated with the EVSE (104);
c. generating, by a power control module (404), at least one control signal;
d. receiving, by a power control unit (210) provided in the EVSE (104), the demand voltage in the translated charging request message;
e. determining, by the power control unit (210), that the demand voltage is less than a minimum voltage of a voltage range of the EVSE (104);
f. in response to determining that the demand voltage is less than the minimum voltage, setting, by the power control unit (210), an operating mode to a low power mode; and
g. outputting, by the power control unit (210), a power signal having the demand voltage according to the low power mode;
h. receiving, by a power unit (220), the power signal;
i. transferring, by the power unit (220), the received power signal to the electric vehicle (106) based upon the at least one control signal.
9. The method as claimed in claim 8, wherein the first charging protocol is Bharat DC 001 and the second charging protocol is Combined Charging System (CCS) Type 2.
10. The method as claimed in claim 8, wherein the method comprises:
a. receiving, by the power control module (404), the demand voltage from the protocol translation module (402); and
b. sending, by the power control module (404), a control message to the protocol translation module (402), the control message comprising the demand voltage;
c. wherein the translated charging request message is transmitted by the protocol translation module (402) in response to receiving the control message.
11. The method as claimed in claim 8, wherein the method comprises:
a. receiving, by the protocol translation module (402), a first message from the electric vehicle (106) according to the first charging protocol, the first message comprising a first header and a first payload;
b. forming, by the protocol translation module (402), a corresponding translated first message according to the second charging protocol, the translated first message comprising a translated first header and a translated first payload;
c. transmitting, by the protocol translation module (402), the translated first message to the EVSE (104);
d. receiving, by the protocol translation module (402), a second message from the EVSE (104) according to the second charging protocol, the second message comprising a second header and a second payload;
e. forming, by the protocol translation module (402), a corresponding translated second message according to the first charging protocol, the translated second message comprising a translated second header and a translated second payload; and
f. transmitting, by the protocol translation module (402), the translated second message to the electric vehicle (106).