DESC:TECHNICAL FIELD
[001] The embodiments herein generally relate to automobiles, and more particularly to hybrid automobile technology, and alternate propulsion architectures thereof.

BACKGROUND
[002] As non-renewable energy resources are decreasing, a reduction in fossil fuel consumption and emissions from vehicles powered by internal combustion engines is necessary. One way to achieve the aforesaid goal is through an electrically driven vehicle. However, such a vehicle has greater body weight and shorter running distance per charge as compared to the conventional vehicles. Such drawbacks can generally overcome by hybrid vehicles. Hybrid vehicles are vehicles with two different fuel sources, which utilize the advantages of an internal combustion engines (using a variety of fuels, generally gasoline or diesel engines) and an electric traction motor into one vehicle. The energy is stored in the fuel of the internal combustion engine and an electric battery set.
[003] Current hybrid vehicles with alternate propulsion have a decoupling mechanism. They may further be selectively driven by either an electric motor or an internal combustion engine acting independently of each other, or by both electric motor and internal combustion engine acting in unison.
[004] Existing systems provide hybrid electric vehicles including an internal combustion engine and an electric motor in which both the motor and the engine provide torque to drive the vehicle directly through a controllable torque transfer unit. Typically the electric motor alone drives the vehicle, using power stored in batteries when the vehicle is at low speeds or in traffic; both the engine and the motor provide torque to drive the vehicle under acceleration and during hill climbing situations; and the internal combustion engine alone drives the vehicle in steady state highway cruising. The internal combustion engine is sized to operate at or near its maximum fuel efficiency during highway cruising. The motor is operable as a generator to charge the batteries as needed and also for regenerative braking. The motor operates at significantly lower currents and higher voltages than conventional mode and has a rated power at least equal to that of the internal combustion engine. However, this concept works on the electric drive mode only under low speed modes as this does not employ any transmission assembly. This results in very low torques at high speeds, which is not sufficient for vehicle propulsion.

OBJECTS
[005] The principal object of the embodiments herein is to provide an alternate propulsion system for hybrid vehicles.
[006] Another object of the embodiments herein is to provide a propulsion system for hybrid vehicles without a decoupling mechanism in power sources used in the hybrid vehicle.
[007] Another object of the embodiments herein is to provide a mechanism to restart a power source in hybrid vehicles.
[008] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by five way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF FIGURES
[009] The embodiments of this invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0010] FIG. 1 depicts a diagrammatic view of an example hybrid powertrain system 100, according to embodiments as disclosed herein;
[0011] FIG. 2 depicts a flow diagram showing conditions under which e-crank mode can be activated, according to embodiments as disclosed herein;
[0012] FIG. 3 depicts an example graph defining operation of a hybrid vehicle in e-crank mode, according to embodiments as disclosed herein;
[0013] FIG. 4 depicts a flow diagram showing conditions under which e-idle mode can be activated, according to embodiments as disclosed herein;
[0014] FIG. 5 depicts an example graph defining operation of the hybrid vehicle in e-idle mode, according to embodiments as disclosed herein;
[0015] FIG. 6 depicts another example graph defining operation of the hybrid vehicle in e-idle mode, according to embodiments as disclosed herein;
[0016] FIG. 7 depicts a flow diagram showing conditions under which e-launch mode (without driver demand) can be activated, according to embodiments as disclosed herein;
[0017] FIG. 8 depicts an example graph defining operation of the hybrid vehicle in e-launch mode (without driver demand), according to embodiments as disclosed herein;
[0018] FIG. 9 depicts a flow diagram showing conditions under which e-launch function (with driver demand) can be activated, according to embodiments as disclosed herein;
[0019] FIG. 10 depicts an example graph defining operation of the hybrid vehicle in e-launch mode (without driver demand to with driver demand), according to embodiments as disclosed herein;
[0020] FIG. 11 depicts a flow diagram showing conditions under which e-sail mode can be activated, according to embodiments as disclosed herein; and
[0021] FIG. 12 depicts an example graph defining operation of the hybrid vehicle in e-sail mode, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0022] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0023] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
[0024] The embodiments herein provide systems and methods of alternate propulsion technique for hybrid vehicles, wherein the power sources are tightly coupled. The hybrid powertrain system for the hybrid vehicle enables control the cut-off of the fuel to a primary power source. This helps in reducing the drag of the primary power source. Further, the hybrid vehicle may be selectively driven by either of the power sources acting independently of each other, or by both the power sources acting in unison, wherein the speed of both power sources is always the same.
[0025] Referring now to the drawings, and more particularly to FIGS. 1 through 12, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0026] Embodiments herein disclose a propulsion system for different operating mode of the vehicle on a powertrain arrangement, wherein there are two power sources. The powertrain system comprises of a primary power source which is a mechanical system producing output torque and a secondary power source which is a mechanical system different from the primary power source, which produces output torque. The primary power source and the secondary power source are rigidly coupled. The propulsion system is a zero emission mode and will be done without providing external means (either forced/external restart) to energize the primary power source and will lead to direct fuel saving at driver end. This can be done when the energy source for the secondary power source goes below a pre-defined threshold. The propulsion system is applicable to all operating modes of the vehicle. The propulsion system is implemented on a powertrain arrangement wherein the secondary power source is further connected to clutch mechanism, which further connects to the transmission. The propulsion system is implemented on a powertrain arrangement wherein the clutch mechanism may be manual mechanism controlled by the driver or the actuation may be automated as in an automatic transmission or an automated manual transmission. The transmission aids in the multiplication of torque from either one of the primary power source, the secondary power source or both together to the wheels. This function is implemented on a powertrain arrangement wherein the primary power source and the secondary power source always rotate at same relative rotational speed. The propulsion system is implemented on a powertrain arrangement wherein the flywheel between the primary power source and secondary power source may be a single mass flywheel or a dual mass flywheel. The propulsion system gets activated on the basis of factors such as the driver based trigger (crank trigger or torque demand), the charge level of secondary power source, vehicle velocity and engine speed. Classic handover happens between functions, such that primary source is not energized and is rotating in same relative speed of secondary source speed due energy to system energy of secondary source. The propulsion system enables fuel saving in the region where it gets activated and reduces the fuel consumption. The propulsion system also reduces the fuel supply to the primary power source and requests the secondary power source to supply the drag torque of the primary power source and the propulsion torque as per the requirement of activated function.
[0027] FIG. 1 depicts a diagrammatic view of an example hybrid powertrain system 100, according to embodiments as disclosed herein. The hybrid powertrain system 100 comprises of a primary power source 5, a flywheel damper arrangement 10, a secondary power source 15, an engine control unit 40 and a motor control unit 45, at least one energy storage device, a clutch assembly 55, at least one transmission unit 85 and a drivetrain which may further comprises of a propeller shaft 80, a differential assembly 105 and wheels 90.
[0028] The primary power source 5 functions as a prime mover of the hybrid vehicle by generating a torque output that is sufficient to drive one or more wheels 90 of the hybrid vehicle. The primary power source 5 can be an internal combustion engine, in which the internal combustion engine can be a spark ignition type or a compression ignition engine type and so on.
[0029] It should be noted at the outset that for purposes of this disclosure, the term hybrid, whether used alone or in combination with terms such as vehicle and/or drivetrain system and/or powertrain system, is used generally to refer to a vehicle having a drive system that includes more than one power source. According to an example embodiment, the hybrid powertrain system 100 utilizes the primary power source 5 and the secondary power source 15. According to other embodiments, the primary power source 5 can be an internal combustion engine or any other suitable power source and the internal combustion engine can be a spark ignition type or a compression ignition engine type or so on, which uses a suitable energy source such as petrol, diesel, CNG (Compressed Natural Gas), LPG (Liquified Petroleum Gas) or any other equivalent means..
[0030] The primary power source 5 can be connected to the flywheel damper arrangement 10. The flywheel damper arrangement 10 may be a single mass flywheel or a dual mass flywheel or a flex plate or any other arrangement which serves the purpose of rotational energy storage.
[0031] The flywheel is further connected to the secondary power source 15. The secondary power source 15 can be provided to assist the primary power source 5 by reducing the driving load of the primary power source 5 (for example, by at least partially sharing the load, or any other suitable means) and/or by augmenting the power of the primary power source 5. In an example embodiment, the secondary power source 15 can be an electric motor generator assembly, powered by the energy storage device 75 and controlled by the motor control unit 45. The electric motor generator assembly can draw power for propulsion through the device 60 which draws energy from energy storage device 75. The device 60 can be at least one of a converter or inverter. The energy storage device 75 can be a battery. The energy storage device 75 can supply the stored electric energy to the secondary power source 15, and for receiving and storing electric energy from the secondary power source 15 when the secondary power source 15 is operated as the electric motor generator. The motor control unit 45 can be coupled with the electric motor generator for controlling the operation of the electric motor generator. The motor control unit 45 controls the electric motor generator based on output signals received from sensor 70, fuel injection quantity 120 and/or the engine control unit 40. The sensor 70 can be associated with the energy storage device 75, is provided to inform the motor control unit 45 about the status of the energy storage device. The status can be the charge level leftover in the energy storage device system.
[0032] The primary power source 5 can be controlled by the engine control unit 40 which operates based on various inputs like vehicle speed 95, engine speed 65, clutch position 200, gear engagement information 210 and accelerator pedal demand 35 and controlling the fuel quantity 25.
[0033] In an embodiment, the engine control unit 40 and the motor control unit 45 may include a controller configured to generate and/or receive one or more control signals for operating the primary power source 5 and the secondary power source 15 respectively. Each of the engine control unit 40 and the motor control unit 45 may further include one or more processors (for example, microcontrollers) and one or more computer readable media (for example, memory) configured to store various data utilized by the engine control unit 40 and the motor control unit 45 and/or instructions that may be executed by the processor(s) to perform various functions. The memory of the engine control unit 40 and the motor control unit 45 may include one or more modules (for example, software modules) including, but not limited to a motor control module and an energy management module. In an example embodiment, the motor control module may generate control signals based on one or more motor assistance profiles based on experimental and/or modeling results. The energy management module is configured to manage energy provided by the energy storage device 75. In an exemplary embodiment, the energy management module may be configured to determine the amount of available charge remaining in battery plus the charge that would become available as a result of regenerative braking and may be configured to change the control signals provided to the secondary power source 15 based on the available charge in the battery and/or other vehicle operating conditions.
[0034] In another example embodiment, the secondary power source 15 can be a hydraulic machine, controlled by the motor control unit 45. The hydraulic machine can draw power for propulsion through a device 60 which draws energy from energy storage device 75. The device 60 can be a valve or any other device which performs equivalent functionality. The energy storage device 75 can be a hydraulic accumulator.
[0035] Still referring to Fig. 1, the secondary power source 15 is further connected to the clutch assembly 55. The primary power source 5 and the secondary power source 15 are rigidly connected to the transmission unit 85 and rotate at same relative speed all the time. The clutch assembly 55 may be manually operated, automatic or can be automated version of the manual type.
[0036] The hybrid powertrain system 100 is provided to initiate an alternate propulsion technique for the hybrid vehicle to control the cut-off of the fuel to the primary power source 5. In an embodiment, the alternate propulsion technique has multiple alternate propulsion such as e-crank mode, e-idle mode, e-launch mode, e-sail mode and so on.
[0037] In the e-crank mode, the secondary power Source 15 can provide overall torque for cranking vehicle during crank phase. The secondary power Source 15 may also provide drag torque of the primary power source 5. The e-crank mode is explained in conjunction with Figs. 2 and 3.
[0038] In the e-idle mode, the secondary power Source 15 can provide the drag torque of the primary power source 5 as well as torque for other accessories and systems present the vehicle when the vehicle is in standstill condition and the engine of the vehicle is in idle condition. The e-idle mode is explained in conjunction with Figs. 4, 5 and 6.
[0039] In the e-launch mode, the secondary power source 15 can provide the drag torque of the primary power source 5 as well as torque for the launch of the vehicle from the standstill condition. In an embodiment, the e-launch mode can further divided into vehicle launch without driver demanded torque function and vehicle launch with driver demanded torque function. The e-launch mode is explained in conjunction with Figs. 7, 8, 9 and 10.
[0040] In the e-sail mode, the secondary power Source 15 can provide the drag torque of the primary power source 5 as well as torque for the propulsion of the vehicle. In the e-sail mode, the vehicle is in running condition. The e-sail mode is explained in conjunction with Figs. 11 and 12.
[0041] FIG. 2 depicts a flow diagram showing conditions under which the e-crank mode can be activated, according to embodiments as disclosed herein. As shown, in step 201, the power train system 100 determines plurality of parameters. In an embodiment, the e-crank mode is enabled on receiving the e-crank trigger from the engine control unit 40 and the motor control unit 45. The e-crank mode can be activated when all the conditions provided below are satisfied. The conditions are based on certain parameters including the gear engagement position 210, the engine speed 65, the vehicle speed 95, the clutch position 200, value of the sensor 70 .The conditions for activating the e-crank mode are
• if the engine control unit 40, the motor control unit 45, the device 60, the energy storage device are operational;
• if value of the gear engagement position 210 is less than G;
• if the engine speed 65 is less than A1 RPM;
• if the vehicle speed 95 is less than B1kmph;
• if the clutch position 200 is less than H; and
• if the value of sensor 70 is less than F1%;
where, values of parameters A1, B1,G, H and F1 can be any suitable predefined value. In an example embodiment, the secondary power source 15 can crank the powertrain from a configurable speed A1 RPM to a configurable speed N RPM, above/below the defined idle speed of the hybrid powertrain system 100 without injecting charge into the primary power source 5.
[0042] FIG. 3 depicts an example graph defining operation of the hybrid vehicle in e-crank mode, according to embodiments as disclosed herein. As shown in the graph, parameter 110 refers to velocity of the vehicle, parameter 120 refers to the fuel injection quantity, parameter 130 refers to speed of the primary power source 5, parameter 140 refers to accelerator pedal during vehicle drive, parameter 200 refers to the clutch position, the parameter 210 refers to the gear engagement information, parameter 190 refers to charge level of the energy storage device 75, parameter 240 shows the trigger for e-crank, parameter 220 refers to output torque of the secondary power source 15 and parameter 230 refers to output torque of the primary power source 5. Region 160 and 180 depicts the region where e-crank function gets activated based on the conditions satisfied as described in figure 2. Region 250 depicts the region for transition from e-crank mode to e-idle mode without energizing the primary power source 5. In the region 160 wherein the e-crank function gets activated, the fuel injection is stopped as per curve 120 thus for a duration of time under 160, the vehicle operates purely on the secondary power source 15 which draws power from 75.
[0043] In another embodiment, once the e-crank mode has been activated and if any of the conditions mentioned in FIG. 2 is not satisfied, the fueling 120 is resumed and hence without a restart mechanism the primary power source 5 starts operation normally.
[0044] FIG. 4 depicts a flow diagram showing conditions under which the e-idle mode can be activated, according to embodiments as disclosed herein. As shown, in step 401, the power train system 100 determines plurality of parameters. The e-idle mode can be activated when all the conditions provided below are satisfied. The conditions are based on certain parameters including the gear engagement position 210, the engine speed 65, the vehicle speed 95, the clutch position 200, value of sensor 70 .The conditions for activating the e-crank mode are
• if the engine control unit 40, the motor control unit 45, the device 60, the energy storage device are operational;
• if value of the gear engagement position 210 is less than G;
• if the engine speed 65 is less than A2 RPM;
• if the vehicle speed 95 is less than B2 kmph;
• if the clutch position 200 is less than H;
• if the value of sensor 70 is less than F1%; and
• if e-crank mode was activated previously or if powertrain rotational speed is reducing and reaching idle;
where, values of parameters A2, B2,G, H and F1 can be any suitable predefined value. In an example embodiment, during the e-idle mode, the secondary power source 15 can maintain overall powertrain at configurable rotational speed (say, N RPM) above/below the defined idle speed for powertrain without injecting charge into the primary power source 5.
[0045] Referring to Figs. 5 and 6 that depicts two example graphs defining operation of the hybrid vehicle in the e-idle mode, according to embodiments as disclosed herein. The parameter 110 refers to the velocity of the vehicle, parameter 120 refers to the injection quantity, the parameter 130 refers to speed of the primary power source 5, parameter 140 refers to the accelerator pedal during vehicle drive, parameter 200 refers to the clutch position, the parameter 210 refers to the gear engagement information, the parameter 190 refers to the charge level of energy storage device 75, parameter 240 shows the trigger for the e-crank mode, parameter 220 refers to the output torque of the secondary power source 15 and parameter 230 refers to output torque of the primary power source 5. The region 160, 180 depicts the region where e-crank mode gets activated based on the satisfied conditions in figure 2. The region 250 depicts the region for transition from e-crank to e-idle without energizing the primary power source 5. In the region 160 and 180 wherein the e-idle function gets activated, the fuel injection is stopped as per curve 120 thus for a duration of time under 160 the vehicle operates purely on the secondary power source 15 which draws power from 75.
[0046] In an embodiment, if any of the conditions mentioned in the Fig. 4 is not satisfied after the mode has been activated, the fueling 120 is resumed with a configurable slope and both the primary power source 5 and the secondary power source 15 can energize the hybrid powertrain system 100 in which the former power contribution will be increasing and the later power contribution will be decreasing till a configurable time. The primary power source 5 can provide the overall required torque afterwards and hence the primary power source 5 starts operation normally without a restart mechanism.
[0047] FIG. 7 depicts a flow diagram showing conditions under which the e-launch mode (without driver demand) can be activated, according to embodiments as disclosed herein. As shown, in step 701, the power train system 100 determines plurality of parameters. The e-launch mode can be activated when all the conditions provided below are satisfied. The conditions are based on certain parameters including the gear engagement position 210, the engine speed 65, the accelerator pedal demand 35, the clutch position 200, value of sensor 70 .The conditions for activating the e-launch mode without driver demand are
• if the engine control unit 40, the motor control unit 45, the device 60, the energy storage device are operational;
• if the accelerator pedal demand 35 is less than X%;
• if the engine speed 65 is less than Y RPM;
• if value of the gear engagement position 210 is equal to V;
• if the clutch position 200 is equal to W; and
• if the value of sensor 70 is greater than Z%;
where, values of parameters X, Y,V, W and Z can be any suitable predefined value. In an example embodiment, during the e-idle mode, the secondary power source 15 can maintain overall powertrain at configurable rotational speed (say, N RPM) above/below the defined idle speed for powertrain without injecting charge into the primary power source 5.
[0048] FIG. 8 depicts an example graph defining operation of the hybrid vehicle in the e-launch mode (without driver demand), according to embodiments as disclosed herein. The parameter 110 refers to velocity of the vehicle, parameter 120 refers to the injection quantity, parameter 130 refers to speed of the primary power source 5, parameter 140 refers to accelerator pedal during vehicle drive, parameter 200 refers to the clutch position, parameter 210 refers to the gear engagement information and parameter 190 refers to the charge level of energy storage device 75. The region 160 wherein the e-launch mode (without driver demand) gets activated, the fuel injection is stopped and the vehicle operates purely on the secondary power source 15 which draws power from 75.
[0049] Fig. 9 depicts a flow diagram showing conditions under which the e-launch mode (with driver demand) can be activated, according to embodiments as disclosed herein. As shown, in step 901, the power train system 100 determines plurality of parameters. The e-launch mode can be activated when all the conditions provided below are satisfied. The conditions are based on certain parameters including the gear engagement position 210, the engine speed 65, the accelerator pedal demand 35, the clutch position 200, value of sensor 70. The conditions for activating the e-launch mode with driver demand are
• if the engine control unit 40, the motor control unit 45, the device 60, the energy storage device are operational;
• if the accelerator pedal demand 35 is greater than X1%;
• if the engine speed 65 is greater than Y1 RPM;
• if value of the gear engagement position 210 is equal to V1;
• if the clutch position 200 is equal to W1; and
• if the value of sensor 70 is greater than Z1%;
where, values of parameters X1, Y1,V1, W1 and Z1 can be any suitable predefined value.
[0050] FIG. 10 depicts an example graph defining operation of the hybrid vehicle in the e-launch mode (without driver demand to with driver demand), according to embodiments as disclosed herein. The parameter 110 refers to velocity of the vehicle, parameter 120 refers to the injection quantity, parameter 130 refers to speed of the primary power source 5, parameter 140 refers to accelerator pedal during vehicle drive, parameter 200 refers to the clutch position, parameter 210 refers to the gear engagement information and parameter 190 refers to the charge level of energy storage device 75. The region 160 wherein the e-launch mode (without driver demand) gets activated, the fuel injection is stopped and the vehicle operates purely on the secondary power source 15 which draws power from 75. In an embodiment, if any of the conditions under Fig. 7 or 9 is not satisfied after the e-launch mode has been activated, the fueling 120 is resumed with a configurable slope and both the primary power source 5 and the secondary power source 15 can energize the hybrid powertrain system 100 in which the former power contribution will be increasing and the later power contribution will be decreasing till a configurable time. The primary power source 5 can provide the overall required torque afterwards and hence the primary power source 5 starts operation normally without a restart mechanism.
[0051] Fig. 11 depicts a flow diagram showing conditions under which the e-sail mode can be activated, according to embodiments as disclosed herein. As shown, in step 1101, the power train system 100 determines plurality of parameters. The e-sail mode can be activated when all the conditions provided below are satisfied. The conditions are based on certain parameters including the accelerator pedal demand 35, the vehicle speed 95, value of sensor 70. The conditions for activating the e-sail mode with driver demand are;
• if the engine control unit 40, the motor control unit 45, the device 60, the energy storage device are operational;
• if the accelerator pedal demand variation is less than or equal to A;
• if the vehicle speed 95 is greater than the lower limit of B kmph and lesser than the higher limit of C kmph;
• if value of the accelerator pedal demand 35 is greater than the lower limit of D% and lesser than the higher limit of E%; and
• if the value of sensor 70 is greater than F%;
where, values of parameters A, B, C, D, E and F can be any suitable predefined value.
[0052] FIG. 12 depicts an example graph defining operation of the hybrid vehicle in the e-sail mode, according to embodiments as disclosed herein. Parameter 110 refers to the vehicle velocity, parameter 120 refers to the injection quantity, parameter 130 refers to speed of the primary power source 5, parameter 140 refers to the accelerator pedal during vehicle drive and 190 refers to the battery charge level. The region 160 and 180 depicts where the e sail mode get activated based on the conditions satisfied in figure 11. In region 160 and 180, the e-sail mode gets activated, the fuel injection is stopped as per curve 150 and 170 and thus for a short duration of time under 160 and 180 the vehicle operates purely on the secondary power source 15 which draws power from 75. In an embodiment, if any of the conditions mentioned in Fig. 11 is not satisfied after the e-sail mode has been activated, the fueling 120 is resumed with a configurable slope and both the primary power source 5 and the secondary power source 15 can energize the hybrid powertrain system 100 in which the former power contribution will be increasing and the later power contribution will be decreasing till a configurable time. The primary power source 5 can provide the overall required torque afterwards and hence the primary power source 5 starts operation normally without a restart mechanism. The fuel saving from the e-sail mode is shown as per curve 150 and 170.
[0053] The propulsion system does not require a separate or an assisted restart of the primary power source. The propulsion system does not require any Front End Auxiliary Drive (FEAD) electrification as the FEAD torque is supplied by the secondary power source. The propulsion system prevents a feeling of any momentary torque loss to the driver during function transitions. The propulsion system does not cause any judder or jerk during the function entry or exit (transitions). The propulsion system implementation does not require additional cost for the function implementation for a Zero Emission Mode. In yet another embodiment, the low voltage board net is optimized to ensure the charge of the energy storage system is depleted to minimum extent.
[0054] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:CLAIMS
What is claimed is:
1. A propulsion system for a vehicle, the propulsion system comprising:
a primary power source and a secondary power source, wherein
the primary power source and the secondary power source are rigidly coupled, such that the primary power source and the secondary power source rotate at same relative speed; and
the primary power source does not require an external means to energize, when a power supply to the secondary power source is below a pre-defined threshold.
2. The propulsion system, as claimed in claim 1, wherein the primary power source and the secondary power source are mechanical systems, wherein the primary power source is different from the secondary power source.
3. The propulsion system, as claimed in claim 1, wherein Front End Auxiliary Drive in the vehicle is not electrified.
4. The propulsion system, as claimed in claim 1, wherein the propulsion system is further configured for
enabling the secondary power source to provide overall torque, when the vehicle is being cranked; and
enabling the secondary power source to provide drag torque to the primary power source.
5. The propulsion system, as claimed in claim 1, wherein the propulsion system is further configured for enabling the secondary power source to provide drag torque to the primary power source and torque for accessories and systems present in the vehicle, when the vehicle is in standstill condition and the vehicle is in idle condition.
6. The propulsion system, as claimed in claim 1, wherein the propulsion system is further configured for
7. The propulsion system, as claimed in claim 1, wherein the propulsion system is further configured for enabling the secondary power source to provide the drag torque of the primary power source and torque for launch of the vehicle, from a standstill condition.
8. The propulsion system, as claimed in claim 1, wherein the propulsion system is further configured for enabling the secondary power source to provide drag torque of the primary power source and torque required for propulsion of the vehicle.
9. A vehicle comprising a propulsion system, the propulsion system comprising:
a primary power source and a secondary power source, wherein
the primary power source and the secondary power source are rigidly coupled, such that the primary power source and the secondary power source rotate at same relative speed; and
the primary power source does not require an external means to energize, when a power supply to the secondary power source is below a pre-defined threshold.
10. The vehicle, as claimed in claim 9, wherein the primary power source and the secondary power source are mechanical systems, wherein the primary power source is different from the secondary power source.
11. The vehicle, as claimed in claim 9, wherein Front End Auxiliary Drive in the vehicle is not electrified.
12. The vehicle, as claimed in claim 9, wherein the propulsion system is further configured for
enabling the secondary power source to provide overall torque, when the vehicle is being cranked; and
enabling the secondary power source to provide drag torque to the primary power source.
13. The vehicle, as claimed in claim 9, wherein the propulsion system is further configured for enabling the secondary power source to provide drag torque to the primary power source and torque for accessories and systems present in the vehicle, when the vehicle is in standstill condition and the vehicle is in idle condition.
14. The vehicle, as claimed in claim 9, wherein the propulsion system is further configured for
15. The vehicle, as claimed in claim 9, wherein the propulsion system is further configured for enabling the secondary power source to provide the drag torque of the primary power source and torque for launch of the vehicle, from a standstill condition.
16. The vehicle, as claimed in claim 9, wherein the propulsion system is further configured for enabling the secondary power source to provide drag torque of the primary power source and torque required for propulsion of the vehicle.