A method and system for an integrated onboard charger of an electric vehicle

Abstract

Disclosed herein is a method of an integrated onboard charger 200 for charging an electric vehicle. The integrated onboard charger 200 comprises a traction converter (103, 202), a traction motor (203) and a battery (105, 204). The integrated onboard charger 200 determines if the vehicle (101) is in a traction mode or a charging mode. Further, based on the determination, receives a power supply (201). Further, operates the traction converter (103, 202) as a boost-buck converter to implement two or more traction motor windings as energy storage elements to charge the battery of the electric vehicle (101).

Description

A METHOD AND SYSTEM FOR AN INTEGRATED ONBOARD CHARGER OF AN ELECTRIC VEHICLETECHNICAL FIELD

[0001] The present invention generally relates to the field of conductive charging, and more particularly relates to a method and system for an integrated onboard charging.BACKGROUND

[0002] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] In recent years, electric vehicles are gaining prominence for their easy and economical maintenance, further they also aid in saving the carbon footprint. However, the electric vehicles face issues related to travelling range limitation, weight of the battery etc. Further, the existing electric vehicle charging can be broadly classified into conductive and wireless charging. Especially in onboard conductive chargers, they are realized with a dedicated power conversion system for charging purposes. Thus, it occupies an extra space and adds weight to the vehicle, limiting the vehicle’s power rating and prolonging the idle charging period.

[0004] Therefore, there is a need for a method and system that overcomes the limitations stated above to implement a reconfigurable integrated onboard charger.SUMMARY

[0005] The present disclosure overcomes one or more shortcomings of the prior art and provides additional advantages. Embodiments and aspects of the disclosure described in detail herein are considered a part of the claimed disclosure.

[0006] In one non-limiting embodiment of the present disclosure, the integrated onboard charger for an electric vehicle is disclosed, the onboard charger comprises a traction motor, a battery, a traction converter, wherein the traction converter is configured to determine a battery voltage and a type of connected input power supply to the vehicle.Further, the traction converter is configured to determine if the vehicle is in a traction mode or a charging mode. Based on the determination the traction converter receives a power supply and operates as one of a boost-buck converter, a boost-active power decoupling converter, a boost converter from the received power supply. Further, the traction converter implements two or more traction motor windings as energy storage elements, from one of the received inputs of the boost-buck converter, the boost-active decoupling converter, the boost converter. Lastly, the traction converter uses the two or more traction motor windings to charge the battery of the electric vehicle during the charging mode.

[0007] In another non-limiting embodiment of the present disclosure, the onboard charger further receives an alternating current (AC) or a direct current (DC) as the power supply.

[0008] In another non-limiting embodiment of the present disclosure, wherein the two or more traction motor windings are further configured to operate at a switching frequency of the traction converter, operates as a higher order ripple filter, by the switching frequency of the traction converter, supresses an electromagnetic torque during the charging mode, by a bidirectional bridgeless input of the traction converter.

[0009] In another non-limiting embodiment of the present disclosure, wherein the onboard charger further configured to transfer power from grid to vehicle (G2V), or a vehicle to grid (V2G) and a vehicle to vehicle (V2V).

[0010] In yet another non-limiting embodiment of the present disclosure, based on the determination that the vehicle is in traction mode the traction converter is further configured to operate as a traction motor controller to propel the vehicle, by receiving power supply from the battery.

[0011] In yet another embodiment of the present disclosure, a method for an integrated onboard charger of an electric vehicle, comprising determining a battery voltage and a type of connected input power supply to the vehicle and further determining if the vehicle is in a traction mode or a charging mode. Based on the determination that the vehicle is in the charging mode, the method further comprises receiving, by a traction converter, apower supply. Further operates as one of a boost-buck converter, a boost-active power decoupling converter, a boost converter, from the received power supply. Further, implements two or more traction motor windings as energy storage elements, from one of the received inputs of the boost-buck converter, the boost-active decoupling converter, the boost converter. Lastly, the method comprises charging, by the two or more traction motor windings, a battery of the electric vehicle during the charging mode.

[0012] In yet another embodiment of the present disclosure, wherein receiving the power supply comprises receiving an alternating current (AC) or a direct current (DC).

[0013] In yet another embodiment of the present disclosure, wherein the two or more traction motor windings are operated by a switching frequency of the traction converter, and the two or more traction motor windings are further operated as a higher order ripple filter, by the switching frequency of the traction converter. Further, the two or more traction motor windings are operated by a bidirectional bridgeless input of the traction converter to supress an electromagnetic torque during charging mode.

[0014] In yet another embodiment of the present disclosure, transferring power from a grid to vehicle (G2V), or a vehicle to grid (V2G) and a vehicle to vehicle (V2V).

[0015] In yet another embodiment of the present disclosure, based on the determination that the vehicle is in traction mode operates the traction converter as a traction motor controller to propel the vehicle, by receiving power supply from the battery.

[0016] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.BRIEF DESCRIPTION OF DRAWINGS

[0017] The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout. Some embodiments of system and / or methods in accordance with embodiments of thepresent subject matter are now described, by way of example only, and with reference to the accompanying Figs., in which:

[0018] Figure 1 depicts an exemplary environment for an integrated onboard charger, in accordance with embodiments of the present disclosure.

[0019] Figure 2 depicts an exemplary block diagram illustrating an integrated onboard charger, in accordance with embodiments of the present disclosure.

[0020] Figure 3 represents an exemplary mode(s) of operation of an integrated onboard charger, in accordance with embodiments of the present disclosure.

[0021] Figure 4 represents charging and propulsion architecture of an integrated onboard charger, Figure 4A and Figure 4B respectively, in accordance with embodiments of the present disclosure.

[0022] Figure 5A-Figure 5C represents simulation of the integrated onboard charger, in accordance with embodiments of the present disclosure.

[0023] Figure 6 represents a flowchart of an exemplary method for integrated onboard charger, in accordance with embodiments of the present disclosure.

[0024] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.DETAILED DESCRIPTION

[0025] The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure.

[0026] The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

[0027] As discussed earlier, onboard conductive chargers are realized with a dedicated power conversion system for charging purposes. Thus, it occupies the space and adds weight to the vehicle, limiting the charger’s power rating and prolonging the idle charging period. Therefore, the existing onboard conductive chargers are inefficient.

[0028] In order to overcome the above-mentioned challenges, the present disclosure provides technique(s) for a reconfigurable integrated onboard charger comprising a traction converter, a traction motor and its windings to implement traction converter as an onboard charger to charge an electric vehicle during charging mode or to propel the vehicle during propulsion mode. A detailed explanation of the proposed technique(s) is disclosed in the forthcoming paragraphs.

[0029] Figure 1 depicts an exemplary environment for an integrated onboard charger, in accordance with embodiments of the present disclosure. The exemplary environment 100 illustrates the electric vehicle 101, which may comprise an integrated onboard charger 102. The integrated onboard charger 102 may further comprise a traction converter 103, one or more traction motor windings 104 and a battery 105.

[0030] In a non-limiting example, the electric vehicle 101 may be a four-wheeler or a multiwheeled vehicle such as any car, jeep, pickup truck or a bus or truck or a two-wheeler etc. In a non-limiting example, the term “electric vehicle” or “vehicle” are interchangeably used in this disclosure. The integrated onboard charger 102 may charge the battery 105 of the vehicle 101 using the traction converter 103 and the traction motor windings 104. A detailed explanation of the reconfigurable integrated onboard charging system and the method of reconfiguring is provided in the forthcoming paragraphs in conjunction with Figures 2-6.

[0031] Figure 2 depicts an exemplary block diagram illustrating an integrated onboard charger, in accordance with embodiments of the present disclosure. The integrated onboard charger 200 may receive an electric power supply to charge electric vehicle from a power supply 201. The integrated onboard charger 200 may comprise a traction converter 202, a traction motor 203, and a battery 204. In a non-limiting example, the onboard charger 200 may transfer power from grid to vehicle (G2V), or a vehicle to grid (V2G) and a vehicle to vehicle (V2V).

[0032] In the illustrated figure, the power supply 201 may supply the electric power such as an alternating current (AC) or a direct current (DC) from a power generation unit or a solar farm respectively. The utility power supply 201 may supply electric power to the traction converter 202. In a non-limiting example, the utility power supply 201 may be an electric grid.

[0033] In one implementation, the traction converter 202 may further comprise a switching circuit 202A. In a non-limiting example, the switching circuit 202A may be a bridgeless switching circuit and may comprise a SIC MOSFETs (silicon carbide MOSFETs), inductors and relays to perform switching. The switching circuit 202 A may receive power from power supply 201 to operate traction converter 202 as an integrated onboard charger. The traction converter 202 may determine the battery voltage and the type of connected input power supply to the vehicle. The traction converter 202 may further determine if the vehicle is in a traction mode or a charging mode. Based on the determination if the vehicle is in the charging mode, the traction converter 202 may operate as a charger. The traction converter 202 may operate as one of a boost-buck converter, a boost-active power decoupling converter, a boost converter from the received power supply 201. Furthermore, the traction converter 202 may operate as an active decoupling circuit, when the power supply is a single-phase AC to avoid heating of the vehicle battery during charging. Further, when the traction converter 202 determines that the vehicle is in propulsion mode, may operate as a traction motor controller to propel the vehicle, by receiving power supply from the battery (204). In a non-limiting example, the terms “integrated onboard charger”, or “onboard charger”, or “charger” are interchangeably used in this disclosure.

[0034] In one implementation, the traction motor 203 may be any electric motor such an alternating current (AC) or a direct current (DC) motor to propel the electric vehicle. In a non-limiting example, the electric motor or the traction motor may be an induction motor or a permanent magnet synchronous motor (PMSM) etc. The traction motor 203 may further comprise one or more traction motor windings 203A. The traction motor windings 203A may be implemented as energy storage elements, from the received input of the boost-buck converter (as discussed in earlier embodiment). The one or more traction motor windings 203 A are used to charge the battery (204) of the electric vehicle during the charging mode. Further, one or more traction motor windings 203A may operate by a switching frequency of the traction converter (202) and may also operate as a higher order ripple filter, by the switching frequency of the traction converter (202) and may further supress an electromagnetic torque during the charging mode, by a bidirectional bridgeless input of the traction converter (202).

[0035] In some implementations, the battery 204 may receive the voltage and power level adapted power supply from the two or more embodiments as discussed earlier and may charge the battery 204. In a non-limiting example, the battery 204 may be any battery that can be implemented in an electric vehicle such as a lithium-ion battery, or a lithiumpolymer battery etc.

[0036] Figure 3 represents an exemplary mode(s) of operation of an integrated onboard charger, in accordance with embodiments of the present disclosure. In an exemplary embodiment, the exemplary mode(s) of operation 300 of the integrated onboard charger are illustrated as 3OOA-3OOD. The exemplary mode 300A may illustrate propulsion mode to operate an integrated onboard charger to propel an electric vehicle. The integrated onboard charger may consume power from battery of the vehicle and may act as a traction motor controller to propel the vehicle.

[0037] In an exemplary embodiment, the exemplary mode 300B is a direct current (DC) charging mode. The power source may be a DC power supply and the integrated onboard charger may receive the DC power supply and may charge the electric vehicle battery.

[0038] In an exemplary embodiment, the exemplary mode 300C is an alternating current (AC) charging mode. The power source may be an AC power supply and the integratedonboard charger may receive the AC power supply and the integrated onboard charger may receive the AC power supply and may charge the electric vehicle battery. Further, in another exemplary embodiment, the exemplary mode 300D is an AC charging mode with active decoupling to charge the electric vehicle battery as described in the earlier embodiments in connection with figure 2.

[0039] Figure 4 represents charging and propulsion control architecture of an integrated onboard charger, Figure 4A and Figure 4B respectively, in accordance with embodiments of the present disclosure. Figure 4A may comprise two controllers to realize the boost and buck functionalities. The inner loop controller (403 A, 404 A) may monitor the input current. The outer voltage loop controller (401 A, 402 A) may monitor the output battery voltage. The switching pulses for the integrated onboard charger are generated in the PWM generator (405A) using the boost / buck duty cycles. Figure 4B illustrates the control architecture of the integrated onboard charger in traction mode, which controls the speed of the traction motor by controlling the switching pulses of the reconfigurable power converter (405B).

[0040] Figure 5A-Figure 5C represents simulation of the integrated onboard charger, in accordance with embodiments of the present disclosure. In an exemplary embodiment, figure 5A illustrates simulation result of an integrated onboard charger a) voltage is 250v, b) voltage is 400v and c) constant current (CC) and constant voltage (cv). In another embodiment, figure 5B illustrates test results of proposed integrated onboard charger at 250v and power output of 1.3kw, 400v and 1.3kw respectively. In another embodiment, figure 5C illustrates total harmonic distortion (THD) and maintaining power factor of the integrated onboard converter at wide output voltage range.

[0041] Figure 6 represents a flowchart of an exemplary method for integrated onboard charger, in accordance with embodiments of the present disclosure. The order in which the method 600 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. However, for ease of explanation, in the embodiments described below, the method 600may be considered to be implemented by integrated onboard charger 200 of the of Fig. 2.

[0042] At step 601, the method 600 may include determining a battery voltage and a type of connected input power supply to the vehicle (101). The traction converter (103, 202) of the integrated onboard charger 200 may determine the battery voltage and the type of connected input power supply, as discussed in figure2.

[0043] At step 602, the method 600 may include determining if a vehicle is in a traction mode or a charging mode. The traction converter (103, 202) of the integrated onboard charger 200 may determine if the vehicle is in a traction mode or a charging mode, as discussed in figure2.

[0044] At step 603, the method 600 may include, based on the determination that the vehicle (101) is in the charging mode, the traction converter (103, 202) may receive a power supply, as discussed in figure 2.

[0045] At step 604, the method 600 may operate the traction converter (103, 202) operates as one of a boost-buck converter, a boost-active power decoupling converter, a boost converter, from the received power supply, as discussed in figure 2.

[0046] At step 605, the method 600 may comprise implementing one or more traction motor windings (104, 203 A) as energy storage elements, from one of the received inputs of the boost-buck converter, the boost-active decoupling converter, the boost converter, as discussed in figure 2.

[0047] At step 606, the method 600 may charge a battery 204 of the vehicle, by the one or more traction motor windings (104, 203A), as discussed in figure 2.

[0048] The order in which the method 600 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described.

[0049] The illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. These examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0050] Alternatives will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the disclosed embodiments.

[0051] In a non-limiting embodiment, the integrated onboard charger 200 may include one or more processors (not shown) and one or more memory (not shown) coupled to one or more hardware and or software components to implement the present disclosure.

[0052] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer- readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer- readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., are non-transitory. Examples include random access memory, read-only memory, volatile memory, non-volatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, and any other known physical storage media.

[0053] Suitable processors include, by way of example, a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor, a graphic processing unit, a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits, Field Programmable Gate Arrays circuits, any other type of integrated circuit, and / or a state machine.

[0054] Advantages of the embodiment of the present disclosure are illustrated herein-As previously indicated, the present disclosure facilitates an efficient onboard conductive charging of the electric vehicles. The present disclosure may reconfigure the traction converter to use traction motor windings as energy storage elements to charge the electric vehicle battery. The proposed integrated onboard charger without need of any additional components or devices charges the electric vehicle in charging and also acts as a motor controller to propel the vehicle during traction mode. The integrated onboard charger effectively integrates propulsion and charging systems. The integrated onboard charger can also maintain power factor and supresses harmonics and electromagnetic torque of the traction motor during charging.

[0055] REFERENCE NUMERALS

Claims

We Claim:

1. An integrated onboard charger (102, 200) for an electric vehicle (101), the onboard charger (102, 200) comprises: a traction motor (203); a battery (105, 204); and a traction converter (103, 202), wherein the traction converter (103, 202) is configured to: determine a battery voltage and a type of connected input power supply to the vehicle (101); and determine if the vehicle (101) is in a traction mode or a charging mode; and based on the determination that the vehicle (101) is in the charging mode, the traction converter (103, 202) is configured to: receive a power supply (201); operate as one of a boost-buck converter, a boost-active power decoupling converter, a boost converter from the received power supply; implement two or more traction motor windings (104, 203 A) as energy storage elements, from one of the received inputs of the boost-buck converter, the boost-active decoupling converter, the buck converter; and use the two or more traction motor windings (104, 203A) to charge the battery (105, 204) of the electric vehicle (101) during the charging mode.

2. The onboard charger (102, 200) as claimed in claim 1, further configured to: receive an alternating current (AC) or a direct current (DC) as the power supply.

3. The onboard charger (102, 200) as claimed in claim 1, wherein the two or more traction motor windings (104, 203 A) are further configured to: operate at a switching frequency of the traction converter (103, 202); operate as a higher order ripple filter, by the switching frequency of the traction converter (103, 202); and supress an electromagnetic torque during the charging mode, by a bidirectional bridgeless input of the traction converter (103, 202).

4. The onboard charger (102, 200) as claimed in claim 1, further configured to: transfer power from a grid to vehicle (G2V), or a vehicle to grid (V2G) and a vehicle to vehicle (V2V).

5. The onboard charger (102, 200) as claimed in claim 1, based on the determination that the vehicle (101) is in traction mode: the traction converter (103, 202) is further configured to operate as a traction motor controller to propel the vehicle (101), by receiving power supply from the battery (105, 204).

6. A method (600) for an integrated onboard charger (102, 200) of an electric vehicle (101), comprising: determining (601) a battery voltage and a type of connected input power supply to the vehicle (101); determining (602) if the vehicle (101) is in a traction mode or a charging mode; based on the determination that the vehicle (101) is in the charging mode: receiving (603), by a traction converter (103, 202), a power supply; operating (604), by the traction converter (103, 202), as one of a boostbuck converter, a boost-active power decoupling converter, a buck converter, from the received power supply; implementing (605), by two or more traction motor windings (104, 203 A), as energy storage elements, from one of the received inputs of the boostbuck converter, the boost-active decoupling converter, the buck converter; and charging (606), by the two or more traction motor windings (104, 203 A), the battery (105, 204) of the electric vehicle (101) during the charging mode.

7. The method as claimed in claim 7, wherein receiving the power supply comprises receiving an alternating current (AC) or a direct current (DC).

8. The method as claimed in claim 7, wherein the two or more traction motor windings (104, 203A) are operated at a switching frequency of the traction converter (103, 202); wherein the two or more traction motor windings (104, 203 A) are further operated as a higher order ripple filter, by the switching frequency of the traction converter (103, 202);wherein the two or more traction motor windings (104, 203 A) are operated by a bidirectional bridgeless input of the traction converter (103, 202) to supress an electromagnetic torque during charging mode.

9. The method as claimed in claim 7, further comprises: transferring power from a grid to vehicle (G2V), or a vehicle to grid (V2G) and a vehicle to vehicle (V2V).

10. The method as claimed in claim 7, based on the determination that the vehicle (101) is in traction mode: operating the traction converter (103, 202) as a traction motor controller to propel the vehicle (101), by receiving power supply from the battery (105, 204).

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