FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE OF THE INVENTION
A PARALLEL HYBRID CONFIGURATION WITH PLANETARY GEARBOX SYSTEM FOR HYBRID VEHICLE AND ITS METHOD
THEREOF
APPLICANT
TATA MOTORS LIMITED
an Indian Company
having its registered office at
Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001,
Maharashtra, INDIA.
INVENTORS
PRASAD BHAUSAHEB WARULE
An Indian National of
TATA MOTORS LIMITED
Bombay House,
24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001,
Maharashtra, INDIA.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is particularly performed.

FIELD OF THE INVENTION
The present invention generally relates to a parallel hybrid configuration of hybrid vehicles. More particularly it relates to a parallel hybrid configuration with planetary gearbox system for hybrid vehicle.
BACKGROUND OF THE INVENTION
Hybrid electric vehicle technology has a good potential to increase vehicle’s fuel economy, improve drivability and reduce emission. Most of the existing hybrid vehicle technologies suggest using two electric motors, complex and expensive planetary / CVT / AMT transmissions, which increases the overall cost of the vehicle significantly. Also packaging hybrid system in an engine compartment is another challenging task due to unavailability of sufficient space.
Most of the Hybrid electric vehicles use an air conditioning system where compressor is driven by separate electric motor, so that when I.C. engine shuts off (e.g. Engine stop during vehicle stop at signal etc.); the air conditioning system will still blow cold air. However electric motor driven compressors are expensive and also this demands increased battery size. This results in increase in vehicle cost and reduced fuel economy.
Due to Increase in vehicle cost, weight and complexity, hybrid vehicles are not gaining popularity.
OBJECTS OF THE INVENTION
One object of the present disclosure is to provide low cost and compact hybrid power train solution.
Another object of the present disclosure is to provide two speed planetary gearbox system for hybrid automatic transmission.

Yet another object of the present disclosure is to use of mechanically driven air conditioning compressor for parallel hybrid vehicle, which can be driven either by engine or by electric motor.
Also, yet another object of the present disclosure is to improve vehicle’s fuel economy, drivability and emissions.
Further object of the present disclosure is to provide hybrid power train that is easy to implement in hybrid configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
FIG. 1 illustrates a schematic representation of hybrid configuration showing engine and electric motor / generator (15) connected to two speed planetary gear box and illustrates air conditioning compressor connected to power-train, in one embodiment of the present disclosure.
FIG. 2 illustrates a schematic representation of hybrid configuration showing planetary carrier, sun gear and ring gear in one embodiment of the present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION
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. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. 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. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. 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.
According to present innovation two-speed planetary gear box is used to transmit power from engine and electric motor / generator (15) to vehicle wheels. Engine is connected to planetary carrier with a clutch and torque converter between them to separate engine from planetary carrier (transmission) as and when needed. Electric motor / generator (15) is connected to planetary carrier shaft after clutch. An air conditioning compressor is also connected to planetary carrier shaft after clutch and are parallel to the electric motor generator (15). There is a provision to lock planetary carrier and ring gear together through a clutch. Also there is a brake at ring gear to lock ring gear as and when needed. Planetary sun is on output shaft and it is connected to vehicle’s differential gear box. Vehicle can be driven in Pure Electric Vehicle (EV) mode and combined power (engine + electric motor / generator) hybrid mode to improve vehicle performance, fuel economy and

emissions. Also there is a provision to drive air conditioning compressor either by engine or traction electric motor through gear box depending on battery SOC and vehicle operating conditions.
A parallel hybrid configuration with planetary gearbox system for hybrid vehicle comprising
an internal combustion engine configured to be connected to at least one planetary carrier (5);
at least one torque converter (4) and at least one power transmission means (3) configured to connect and disconnect said internal combustion engine to and from said planetary carrier (5); at least one electric motor/generator (15) is configured to be connected to planetary carrier shaft after clutch; at least one air conditioning compressor is configured to be connected to planetary carrier shaft after clutch; at least one ring gear (14) of said planetary gear box configured to be in continuous meshing with planetary carrier gears; at least one power transmission means (11) mounted on said planetary carrier (5) and said ring gear (14) configured to connect and disconnect said planetary carrier (5) with ring gear (14) for changing the transmission ratio of the planetary gearbox system; at least one braking means (10) configured for locking / unlocking of said ring gear (14) of the planetary gear box for effecting change in the gear ratio; at least one planetary sun gear (2) of said planetary transmission system configured for mounting an output shaft wherein the other end of said output shaft is configured for mounting reduction gear (1) for connecting it to the vehicle differential gear box (8).
The planetary gearbox system comprises of a two speed planetary gear box hybrid power transmission unit.The power transmission means (3,11) are clutch. The planetary gearbox system is configured to run the system in electric vehicle (EV) mode, hybrid mode, idle battery charging mode, regenerative braking mode, hybrid air conditioning mode. The clutch (3) is configured to be fitted between said torque converter (4) and the planetary carrier (5) to selectively isolate from the transmission during pure EV mode of the vehicle and in engine stationary

state. The air conditioning compressor unit and said electric motor generator unit (15) connected to planetary carrier shaft are configured to be connected parallel to each other.
The torque converter (4) is configured to be closed lock up clutch to lock its impeller and turbine together avoiding power loss at torque converter during low load, high speed conditions. The electric motor / generator (15) is configured to be connected to said carrier gear (5) through reduction gear (12). The torque converter (4) is configured to amplify engine torque during low vehicle speed, improve gear shift quality and to reduce jerk. The reduction gear (12) is configured to be selected to fulfil vehicle gradient requirements during EV mode.
The electric motor/generator (15) is configured to run the vehicle with higher gear ratio or lower gear ratio in electric vehicle (EV) mode, with a predetermined speed and load by maintaining engine in switched off mode and clutch (3) open to isolate engine from transmission. The I.C. Engine and electric motor/ generator (15) are configured to provide power required at wheels in hybrid mode with clutch (3) in fully or partially closed to connect I.C. Engine to planetary carrier to run vehicle with higher gear ratio or lower gear ratio. The Hybrid mode said torque converter is configured to unlock up and clutch is configured to remain closed during vehicle take off and crawling.
The clutch (3) is configured to be closed for coupling engine to planetary carrier (5) by maintaining clutch (11) and brake (10) in open condition allowing ring gear (14) to rotate in Idle battery charging mode and planetary sun gear is configured to be locked due to wheels (6 &7) braking with stationary vehicle and said engine is configured to run and drive the generator to charge the battery with defined power wherein the torque converter (4) clutch remain locked to reduce coupling losses. The clutch (3) is configured to be opened to detach engine from transmission during braking and with battery state of charge (SOC) below predetermined threshold, hybrid system enters into regenerative braking to

provide said electric motor-generator (15) as a generator by charging battery while transmission remains in 1st gear or 2nd gear depending on vehicle speed.
The I.C. Engine or Electric motor / generator (15) or both are configured to drive the A/C compressor connected to the planetary carrier (5) through a gear (13) in vehicle running condition. The A/C compressor is configured to be run by electric motor / generator (15) at constant rpm at vehicle stationary, planetary sun locked through vehicle inertia and wheel braking, ring gear (14) configured to rotate in brake (10) and clutch (11) in opened condition with battery state of charge (SOC) is high. The A/C compressor (16) is configured to be run by I.C. engine coupled to planetary carrier (5) by closing said clutch (3), opening brake (10) and clutch (11) in vehicle stationary condition and with battery state of charge (SOC) low. The Electric motor / generator (15) is configured to be run by I.C. engine coupled to planetary carrier (5) by closing a clutch (3), opening brake (10) and clutch (11) in vehicle stationary condition for charging battery during battery state of charge (SOC) is low.
A Method of hybrid power transmission with two speed planetary gearbox system comprising the steps of:
• Locking planetary carrier (5) and ring gear (14) by closing clutch (11) and by opening the brake (10) connected to the ring gear at the same time for achieving higher gear ratio (1st gear) for planetary gearbox system;
• Locking the ring gear (14) by a closing the brake (10) connected to it and at the same time opening the clutch (11) between carrier gear (5) and ring gear (14) for achieving lower gear ratio (2nd gear) for planetary gearbox system;
• Opening clutch (3) to detach engine from transmission and engine will be switched off, engaging 1st or 2nd gear as explained in gear shifting, depending on vehicle operating condition to change the hybrid power transmission system from Hybrid mode to Electric Vehicle (EV) mode;
• For transition from EV mode to Hybrid mode cranking engine through its starter and engaging clutch (3) gradually during engine speed synchronization

with planetary carrier(5), engaging 1st or 2nd gear as explained above in gear shifting, depending on vehicle operating condition, alternatively engine can be cranked by electric motor and by opening brake (10) and clutch (11) and gradually engaging clutch (3), lock up clutch in torque converter (4) remains open to amplify Electric motor torque during engine cranking, engaging clutch (3) with started engine, engaging 1st or 2nd gear as explained in gear shifting, depending on vehicle operating condition, lock up clutch in torque converter (4) will be closed after engine cranking, depending on vehicle operating conditions like load and speed.
As shown in fig. 1, two speed planetary gear box is used as a hybrid power transmission unit. Its planetary sun (2) acts as an output shaft, which is connected to the vehicle’s differential gear box (8) through reduction gears (1). Brake (10) is connected to the Ring gear (14) of the planetary gear box, so that ring gear can be locked / unlocked as and when needed to change the gear ratio. Clutch (11) on planetary gear box is used to lock / unlock planetary Carrier (5) and ring gear (14) together as and when needed to change the gear ratio. Internal combustion engine (I.C. Engine) is connected to the planetary carrier of planetary gear box through torque converter (4) and clutch (3). Torque converter (4) has a normally closed lock up clutch to lock its impeller and turbine together to avoid power loss at torque converter during low load, high speed conditions. Torque converter (4) amplifies engine torque during low vehicle speed. Also it improves gear shift quality and reduces jerk. Clutch (3) is fitted between Torque converter (4) and the planetary carrier (5), so that engine and torque converter can be isolated from the transmission during pure Electric Vehicle (EV) mode of the vehicle and when engine is not running. Electric motor / generator is connected to the carrier gear (5) through reduction gear (12).The reduction gear is selected to fulfil vehicle gradient requirements during Electric Vehicle (EV) mode. Gear shifting:
Higher gear ratio (1st gear) is achieved through locking planetary carrier (5) and ring gear (14) by closing clutch (11) and by opening the brake (10) connected to

the ring gear at the same time. Lower gear ratio (2nd gear) is achieved through locking the ring gear (14) by a closing the brake (10) connected to it and at the same time opening the clutch (11) between carrier gear (5) and ring gear (14).
Hybrid modes:
1) Pure Electric Vehicle EV mode: When battery State of Charge (SOC) is sufficiently high, vehicle can run in pure Electric Vehicle (EV) mode up to certain speed and load. Engine is switched off during Pure Electric Vehicle (EV) mode. Clutch (3) remains open during pure Electric Vehicle (EV) mode, to isolate engine from transmission. Vehicle can run with higher gear ratio or lower gear ratio as explained above, depending on vehicle operating conditions.
2) Hybrid mode: When battery State of Charge (SOC) is low or load is high or vehicle is running at a speed above certain threshold, both, I.C. Engine and electric motor/ generator will provide power required at wheels. During Hybrid mode clutch (3) will remain fully or partially closed so that I.C. Engine will remain connected to planetary carrier as per requirement. Vehicle can run with higher gear ratio or lower gear ratio as explained above, depending on vehicle operating conditions. During Hybrid mode, engine output energy can be used to drive vehicle and also to charge the battery if required. During vehicle take off and crawling torque converter lock up clutch remains open.
3) Idle battery charging: if battery State of Charge (SOC) is very low, it can be charged during idling. During this mode, clutch (3) is closed so that engine can be coupled to planetary carrier (5). Clutch (11) remains open and brake (10) is also open allowing ring gear (14) to rotate. Planetary sun gear is locked due to wheels (6 &7) braking with stationary vehicle. Engine drives the generator to charge the battery with defined power. Torque converter (4) clutch remain locked to reduce coupling losses.
4) Regenerative braking: During braking and if battery State of Charge (SOC) is not above certain threshold, hybrid system enters into regenerative braking. Clutch (3) will be opened to detach engine from transmission. Electric

motor-generator acts as a generator. Either 1st gear or 2nd gear will be selected so
that generator can charge battery with maximum possible electric energy.
5) Hybrid Mode transitions:
a) Transition from Hybrid mode to Electric Vehicle (EV) mode: During this transition, clutch (3) will be opened to detach engine from transmission and engine will be switched off. 1st or 2nd gear will be engaged as explained in gear shifting, depending on vehicle operating condition.
b) Transition from Electric Vehicle (EV) mode to Hybrid mode: During this transition, engine will be cranked through its starter and then clutch (3) will be gradually engaged during speed synchronization with planetary carrier of transmission. 1st or 2nd gear will be engaged as explained above, depending on vehicle operating condition. Alternatively engine can be cranked by electric motor also by opening brake (10), opening clutch (11) and gradually engaging clutch (3). Torque converter (4) lock up clutch remains open to amplify Electric motor torque during engine cranking. Electric motor will provide the torque necessary to crank the engine. Once engine started with clutch (3) engaged, 1st or 2nd gear will be engaged as explained in gear shifting, depending on vehicle operating condition. Torque converter lock up clutch (4) will be closed after engine cranking, depending on vehicle operating conditions like load and speed.
Hybrid Air conditioning:
Mechanically driven A/C compressor (16) is connected to the planetary carrier (5)
through a gear (13). Whenever vehicle is running, carrier gear gets the power from
power unit (either I.C. Engine or Electric motor / generator or both), which can be
used to drive A/C compressor (16) as well.
When vehicle is stationary, planetary sun gets locked through vehicle inertia and
wheel braking; Ring gear (14) is allowed to rotate by opening the brake (10) at
ring gear (14). Clutch (11) remains open. If battery State of Charge (SOC) is high,
electric motor / generator will run provide the power just sufficient to fulfil A/C
compressor (16) power requirement. If battery SOC is low, I.C. engine will be
coupled to planetary carrier (5) by closing a clutch (3) and run in IDLE speed

control mode and provide the power to run A/C compressor (16). Thus mechanical A/C compressor (16) is used to fulfil air-conditioning requirements of Hybrid electric vehicle in all operating conditions. Air conditioning works in similar way during idle battery charging. Lock up clutch of torque converter remains closed when A/C is on while vehicle is stationary.
Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition,

even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

We Claim:
1. A parallel hybrid configuration with planetary gearbox system for hybrid
vehicle comprising
an internal combustion engine configured to be connected to at least one planetary carrier (5);
at least one torque converter (4) and at least one power transmission means (3) configured to connect and disconnect said internal combustion engine to and from said planetary carrier (5);
at least one electric motor/generator (15) is configured to be connected to planetary carrier shaft after clutch;
at least one air conditioning compressor (16) is configured to be connected to planetary carrier shaft after clutch;
at least one ring gear (14) of said planetary gear box configured to be in continuous meshing with planetary carrier gears;
at least one power transmission means (11) mounted on said planetary carrier (5) and said ring gear (14) configured to connect and disconnect said planetary carrier (5) with ring gear (14) for changing the transmission ratio of the planetary gearbox system;
at least one braking means (10) configured for locking / unlocking of said ring gear (14) of the planetary gear box for effecting change in the gear ratio;
at least one planetary sun gear (2) of said planetary transmission system configured for mounting an output shaft wherein the other end of said output shaft is configured for mounting reduction gear (1) for connecting it to the vehicle differential gear box (8).
2. A parallel hybrid configuration with planetary gearbox system for hybrid
vehicle as claimed in claim 1 wherein said planetary gearbox system
comprises of a two speed planetary gear box hybrid power transmission unit.

3. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said at least one power transmission means (3,11) are clutch.
4. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said planetary gearbox system is configured to run the system in electric vehicle (EV) mode, hybrid mode, idle battery charging mode, regenerative braking mode, hybrid air conditioning mode.
5. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said clutch (3) is configured to be fitted between said torque converter (4) and the planetary carrier (5) to selectively isolate from the transmission during pure EV mode of the vehicle and in engine stationary state.
6. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said air conditioning compressor unit (16) and said electric motor generator unit (15) connected to planetary carrier shaft are configured to be connected parallel to each other.
7. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said torque converter (4) is configured with a closed lock up clutch to lock its impeller and turbine together avoiding power loss at torque converter during low load, high speed conditions.
8. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said electric motor / generator (15) is configured to be connected to said carrier gear (5) through reduction gear (12).

9. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said torque converter (4) is configured to amplify engine torque during low vehicle speed, improve gear shift quality and to reduce jerk.
10. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said reduction gear (12) is configured to be selected to fulfil vehicle gradient requirements during EV mode.
11. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said electric motor/generator (15) is configured to run the vehicle with higher gear ratio or lower gear ratio in electric vehicle (EV) mode, with a predetermined speed and load by maintaining engine in switched off mode and clutch (3) open to isolate engine from transmission.
12. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said I.C. Engine and electric motor/ generator (15) are configured to provide power required at wheels in hybrid mode with clutch (3) in fully or partially closed to connect I.C. Engine to planetary carrier to run vehicle with higher gear ratio or lower gear ratio.
13. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein in said Hybrid mode said torque converter is configured with normally closed lock up clutch to keep it open during engine cranking through electric motor/generator (15), vehicle take off and crawling.
14. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said clutch (3) is configured to be closed for coupling engine to planetary carrier (5) by maintaining clutch (11)

and brake (10) in open condition allowing ring gear (14) to rotate in Idle battery charging mode and planetary sun gear is configured to be locked due to wheels (6 &7) braking with stationary vehicle and said engine is configured to drive the generator to charge the battery with defined power wherein the torque converter (4) lock up clutch remain locked to reduce coupling losses inside torque converter.
15. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said clutch (3) is configured to be opened to detach engine from transmission during braking and with battery state of charge (SOC) below predetermined threshold, hybrid system enters into regenerative braking to provide said electric motor-generator (15) as a generator by charging in 1st gear or 2nd gear.
16. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said I.C. Engine or Electric motor / generator (15) or both are configured to drive the A/C compressor (16) connected to the planetary carrier (5) through a gear (13) in vehicle running condition.
17. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said A/C compressor (16) is configured to be run by electric motor / generator (15) at constant rpm at vehicle stationary, planetary sun locked through vehicle inertia and wheel braking, ring gear (14) configured to rotate in brake (10) and clutch (11) in opened condition with battery state of charge (SOC) is high.
18. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said A/C compressor (16) is configured to be run by I.C. engine coupled to planetary carrier (5) by closing said clutch

(3), opening brake (10) and clutch (11) in vehicle stationary condition and with battery state of charge (SOC) low.
19. A parallel hybrid configuration with planetary gearbox system for hybrid vehicle as claimed in claim 1 wherein said Electric motor / generator (15) is configured to be run by I.C. engine coupled to planetary carrier (5) by closing a clutch (3), opening brake (10) and clutch (11) in vehicle stationary condition for charging battery during battery state of charge SOC is low.
20. A Method of hybrid power transmission with two speed planetary gearbox system comprising the steps of:

• Locking planetary carrier (5) and ring gear (14) by closing clutch (11) and by opening the brake (10) connected to the ring gear at the same time for achieving higher gear ratio (1st gear) by gear shifting for planetary gearbox system;
• Locking the ring gear (14) by a closing the brake (10) connected to it and at the same time opening the clutch (11) between carrier gear (5) and ring gear (14) for achieving lower gear ratio (2nd gear) by gear shifting for planetary gearbox system;
• Opening clutch (3) to detach engine from transmission and engine will be switched off, engaging 1st or 2nd gear as explained in gear shifting, depending on vehicle operating condition to change the hybrid power transmission system from Hybrid mode to Electric Vehicle (EV) mode;
• Cranking engine through its starter and engaging clutch (3) gradually during speed synchronization with planetary carrier (5), engaging 1st or 2nd gear as explained above in gear shifting, depending on vehicle operating condition, alternatively cranking engine by electric motor and by opening brake (10) and clutch (11) gradually engaging clutch (3), lock-up clutch of torque converter (4) in open condition to amplify electric motor torque during engine cranking, engageing clutch (3) with started engine, engaging 1st or 2nd gear as explained in gear shifting,

depending on vehicle operating condition, lock-up clutch of torque converter(4) in close condition after engine cranking, depending on vehicle operating conditions like load and speed to change the transition from Electric Vehicle (EV) mode to Hybrid mode.