FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10; rule 13]
TITLE: “A SYSTEM FOR OPERATING A COMPRESSOR OF HVAC UNIT IN A
HYBRID VEHICLE”
Name and Address of the Applicant:
TATA MOTORS LIMITED; an Indian company having a registered address at Bombay
House, 24 Homi Mody Street, Hutatma Chowk, Mumbai - 400001 Maharashtra, India.
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure, in general, relates to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to operation of a Heating, Ventilating and Air conditioning (HVAC) unit in a hybrid vehicle. Further, embodiments of the present disclosure relate to a system and a method for operating a compressor of the HVAC unit in the hybrid vehicle having P-3 configuration.
BACKGROUND OF THE DISCLOSURE
Heating, Ventilation and Air conditioning (HVAC) units in the vehicles are generally used for improving comfort and to address requirement of controlling temperature within a passenger cabin and/or a driver cabin of the vehicle, relative to climate surrounding the vehicle. The HVAC unit is configured to regulate at least one of temperature and humidity within the passenger cabin and/or the driver cabin of the vehicle, even when the vehicle is in a state of rest or during state of motion. Generally, the HVAC unit includes a compressor, that may be coupled to a prime mover of the vehicle, where the compressor may be configured to assist in supplying heat treated fluid into the cabin of the vehicle to control the temperature within such cabin.
Conventionally in the hybrid vehicles, the compressor of the HVAC unit is directly coupled to an engine of the vehicle, to derives power from the engine. Further, the compressor may be operable to actuate the HVAC unit when the engine is in a running condition, while the compressor may be inoperative when the engine is in non-operative condition. With such configuration, the HVAC unit tends to be inoperative when the engine is in the non-operative condition, whereby rendering changes in desired ambience within the cabin of the vehicle. Also, in some configurations of the hybrid vehicles, operations of an electric motor in the hybrid vehicle and an auto start-stop function associated with the engine and the electric motor may be disabled, when the HVAC unit is being operated by the engine. Such configuration is to ensure that the HVAC unit remains operational and is being operated via the engine of the vehicle. However, when the vehicle is in halt position [or non-mobile condition], operating the engine to the running condition for operating the compressor and in-turn the HVAC unit, may result in high-fuel consumption, which may not be compensated with the auto start-stop module or the electric motor that would be disabled from operations.

To overcome such situation, with advent of technology, configuration for the hybrid vehicles have been developed where an auxiliary motor may be coupled to the compressor of the HVAC unit. The auxiliary motor may be configured to operate the compressor irrespective of condition of the engine, whereby addressing problems associated with high-fuel consumption rate. However, such configuration would require adequate space to accommodate the auxiliary motor, which renders the configuration bulky and heavy. Such limitations, generally, hinder performance and load carrying capacity of the hybrid vehicles. Additionally, the separate auxiliary motor for HVAC increases overall system cost. In addition, when the vehicle is in the halt position, operation of the auxiliary motor may drain the charge in the battery of the vehicle, whereby affecting operations of components such as, but not limited to, a headlight, the auto start-stop module, and the like, which generally are essential for the vehicle.
The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the conventional configuration of the hybrid vehicle for operating the HVAC unit.
SUMMARY OF THE DISCLOSURE
One or more shortcomings of the prior art are overcome by a system and a method as claimed and additional advantages are provided through the system and the method as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure a system for operating a compressor of a Heating, Ventilation and Air conditioning (HVAC) unit in a hybrid vehicle is disclosed. The hybrid vehicle includes a powertrain configuration including an engine, a transmission coupled to the engine, and a traction motor coupled to an output shaft of transmission. Further, the system includes a power transmission unit coupling the compressor to an output shaft of the traction motor. The system further includes an electronic control unit (ECU) as hybrid control unit, being communicatively coupled to a battery management unit, the engine, transmission, the traction motor, an auto start-stop module associated with the engine, a speed sensor, clutch arrangement, actuation unit, and second clutch. The electronic control unit is configured to

determine operational condition of the vehicle, which is at least one of an electric mode, a hybrid mode, and an engine mode. The ECU is further configured to receive, speed of the vehicle based on a signal from the speed sensor. Based on the speed of the vehicle, ECU is configured to determine state of the vehicle either standstill or running. Based on determined speed of the vehicle, the ECU is configured to operate an actuation unit to disengage the traction motor from the output shaft of the transmission, upon receiving a signal to operate the HVAC unit of the vehicle. Such an operation of the actuation unit is performed by the ECU when, the speed of the vehicle is zero (vehicle is at standstill) in the hybrid mode or the electric mode of operation of the vehicle, such that the traction motor drives the compressor of the HVAC unit.
In an embodiment of the present disclosure, the ECU is configured to monitor state of charge of a power source (traction battery) coupled to the traction motor, when the traction motor is driving the compressor of the HAVC unit, and when the speed of the vehicle is zero in the hybrid mode and the electric mode of operation of the vehicle. Further, the ECU is configured to operate the engine in an idle mode, to energize the power source, when state of the charge in the power source falls below a predetermined operational limit.
In an embodiment of the present disclosure, the engine is operated in the idle mode by disconnecting an output shaft of the engine, from the transmission.
In an embodiment of the present disclosure, the engine is coupled to the transmission through a clutch arrangement, for selectively disconnecting the engine from the transmission to operate the engine in the idle mode.
In an embodiment of the present disclosure, the power source is energized by operating a generator of a start-stop module coupled to the engine.
In an embodiment of the present disclosure, the traction motor is coupled to the output shaft of the transmission through actuation unit, at least one of a first clutch and an epicyclic gear assembly.
In an embodiment of the present disclosure, the compressor is coupled to the power transmission unit through a second clutch.

In an embodiment of the present disclosure, the power transmission unit is at least one of a belt drive, a gear drive and a chain drive.
In another non-limiting embodiment of the present disclosure, a method for operating a compressor of a Heating, Ventilation and Air conditioning (HVAC) unit in a hybrid vehicle is disclosed. The hybrid vehicle includes a powertrain configuration having an engine, a transmission coupled to the engine, and a traction motor coupled to an output shaft of the transmission, and wherein the compressor is coupled to an output shaft of the traction motor through a power transmission unit. The method includes steps of determining, by an electronic control unit (ECU), an operational condition of the vehicle, wherein the vehicle is operable in at least one of an electric mode, a hybrid mode, and an engine mode. The ECU is further configured to determine, speed of the vehicle based on a signal received from the speed sensor. Based on the speed of the vehicle, ECU is configured to determine state of the vehicle either standstill or running. Based on determined speed of the vehicle, the ECU is configured to operate an actuation unit to disengage the traction motor from the output shaft of the transmission, upon receiving a signal to operate the HVAC unit of the vehicle. Such an operation of the actuation unit is performed by the ECU when, the speed of the vehicle is zero in the hybrid mode and the electric mode of operation of the vehicle, such that the traction motor drives the compressor of the HVAC unit. When vehicle is in running state, either in hybrid or EV mode, traction motor remains coupled to output shaft of transmission. Compressor of HVAC unit will be coupled to traction motor upon receiving signal to operate HVAC unit of vehicle. HVAC unit is powered either by traction motor or by engine depending on hybrid mode or electric mode of vehicle operation.
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 THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. 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:
Figure 1 illustrates a schematic diagram of a system for operating a compressor of a HVAC unit, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates a schematic diagram of the system for operating a compressor of a HVAC unit, in accordance with another embodiment of the present disclosure.
Figure 3 is a flow chart illustrating sequence of steps involved in a method for operating the system of Figures 1 and 2.
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 and method illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof has been shown by the way of example in the figures and will be described below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, assembly, mechanism, system, method that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

Embodiments of the present disclosure disclose a system and method for operating a compressor of a Heating, Ventilation and Air conditioning (HVAC) unit in a hybrid vehicle is disclosed. In an embodiment the system and the method is applicable for hybrid vehicle with P-3 configuration. Such configuration of the hybrid vehicle includes a powertrain including an engine, a transmission coupled to the engine, and a traction motor coupled to an output shaft of transmission. The system according to various embodiments of the disclosure includes a power transmission unit coupling the compressor to an output shaft of the traction motor. An electronic control unit (ECU), being communicatively coupled to a battery management unit, the engine, transmission, the traction motor, an auto start-stop module associated with the engine, a speed sensor, clutch arrangement, actuation unit, and second clutch.. The electronic control unit is configured to determine operational condition of the vehicle, which is at least one of an electric mode, a hybrid mode, and an engine. The ECU is further configured to receive, speed of the vehicle based on a signal from the speed sensor. Based on speed of the vehicle ECU is configured to determine state of the vehicle either standstill or running. Based on determined speed of the vehicle, the ECU is configured to operate an actuation unit to disengage the traction motor from the output shaft of the transmission, upon receiving a signal to operate the HVAC unit of the vehicle. Such an operation of the actuation unit is performed by the ECU when, the speed of the vehicle is determined to be zero in the hybrid mode and the electric mode of operation of the vehicle, such that the traction motor drives the compressor of the HVAC unit. With such configuration, as the system may be configured to operate the HVAC unit with the traction motor, fuel consumed by the engine during operation of the HVAC unit may be regulated. Also, as the system couples the compressor of the HVAC unit to the traction motor which drives the vehicle, necessity for an auxiliary motors for operating the compressor is eliminated, while further mitigates additional cost and load of the auxiliary motor on the vehicle.
The disclosure is described in the following paragraphs with reference to Figures 1 and 3. In the figures, the same element or elements which have same functions are indicated by the same reference signs. It is to be noted that, the vehicle is not illustrated in the figures for the purpose of simplicity. One skilled in the art would appreciate that the system and the method as disclosed

in the present disclosure may be used in any hybrid vehicle including but not liming to heavy and light commercial vehicles, load carrying vehicles, and the like.
Figure 1 is an exemplary embodiment of the present disclosure which illustrates a system (100) for operating a compressor (1) of a Heating, Ventilation and Air conditioning (HVAC) unit (200) in a hybrid vehicle. The compressor (1) may be coupled to a reservoir and/or a fluid supplying unit, for extracting and circulating a fluid that may adaptably modify and/or regulate ambience in a cabin of the hybrid vehicle [hereafter referred to as “the vehicle”]. In an embodiment, the cabin may be at least one of a passenger cabin, a driver cabin, a localized space within the passenger cabin, and any other location confined by Body-in-white and windshields of the vehicle. Further, the fluid may modify and/or regulate at least one of temperature and moisture within the cabin, as per required ranges set by a user or an operator to set ambiance in the cabin to a predefined value. The predefined value may be set by operating selective actuation console [not shown in Figures] on an instrument panel in the cabin, where the actuation console may be either physically or remotely operated by the user for actuating the HVAC unit.
In an embodiment, the vehicle may include a powertrain, of which components may be arranged in a myriad of configurations, where components of the powertrain may include, but may not be limited to, an engine (2), a traction motor (4), a transmission (3), and a differential unit. Configurations of the powertrain may be defined based on position and/or location of the traction motor (4) in the powertrain, relative to position of the engine (2) therein. In the exemplary embodiment, configuration of the powertrain includes the transmission (3) being coupled to the engine (2) and the traction motor (4) being coupled to an output shaft of the transmission (3), where the engine (2) and the traction motor (4) are off-set about operational axes. Such configuration of the powertrain in the vehicle are generally termed as P3-configuration, where no direction and/or axial relation persists between the engine (2) and the traction motor (4), while both the engine (2) and the traction motor (4) are capable of individually and in combination supply power to wheels of the vehicle, via the transmission (3) and the differential unit. Further, the traction motor (4) may be offset from operational axis of the engine (2) and connected to the output shaft of the transmission (3) by means of a drive mechanism. The driving mechanism (14) may be including, but not limited to, a chain drive, a

belt drive, a gear drive and any other mechanism that may aid in off-setting operation axis of the engine (2) and the traction motor (4).
The system (100) of the exemplary embodiment may also be operable in a configuration of the powertrain where the traction motor (4) may be coupled to the output shaft of the transmission (3) and that the traction motor (4) is in-line with the engine (2). Also, with such configuration of the powertrain, the vehicle may be operable in various modes such as, an electric mode, an engine (2) mode and a hybrid mode. In the electric mode, the vehicle may be operable only by the traction motor (4), i.e. power may be deliverable to wheels of the vehicle, via the transmission (3) and the differential unit, by operation of the traction motor (4) alone and disengagement of clutch arrangement (15). In the engine (2) mode, the vehicle may be operable only by the engine (2), i.e. power may be deliverable to wheels of the vehicle, via the transmission (3) and the differential unit, by operation of the engine (2) alone and engagement of clutch arrangement (15). In the hybrid mode, the vehicle may be operable by combined operation of the traction motor (4) and the engine (2). Further, the vehicle may attain mobility in each mode upon engagement/disengagement of a clutch arrangement (15) associated with the powertrain or operation of gears in the transmission (3).
Again referring to Figure 1, the compressor (1) of the HVAC unit in the system (100) may be coupled to the powertrain so that, power required for operation of the compressor (1) and in-turn the HVAC unit (200) may be received from the powertrain. In the exemplary embodiment, the compressor (1) is coupled to an output shaft of the traction motor (4) via a power transmission unit (6), where the power transmission unit (6) may be positioned between the traction motor (4) and the driving mechanism (14) connecting the output shaft of the transmission (3) with the traction motor (4). An actuation unit (12) may be positioned between the output shaft of the transmission (3) and the power transmission unit (6) so that, the compressor (1) may be operable by the traction motor (4) alone or in combination with the engine (2), based on operation of the actuation unit (12). A second clutch (13) may be coupled between the power transmission unit (6) and the compressor (1) such that, power from the traction motor (4) may be selectively supplied to the compressor (1). The second clutch (13) may also ensure that the compressor (1) may be disengaged from the traction motor (4) during operation the vehicle in the engine (2) mode or when HVAC operation is not required. The

compressor (1) upon receiving power from the traction motor (4) through the power transmission unit (6) or from the engine (2) through the transmission (3), operates HVAC fluid supplying unit, for extracting and circulating a fluid that may adaptably modify and/or regulate ambience in a cabin of the vehicle
The system (100) further includes an electronic control unit [hereafter referred to as ECU (7)], which may be communicatively coupled to a battery management unit (8) in the vehicle, an auto start-stop module (9) associated with the engine (2), a speed sensor (10) associated with the transmission (3), the engine (2), and the traction motor (4), for suitably operating the compressor (1). To optimize performance of the vehicle, the ECU (7) may be configured to determine operational condition of the vehicle, which may be at least one of the electric mode, the hybrid mode, and the engine (2) mode. The ECU (7) may further determine speed of the vehicle based on a signal received from the speed sensor (10). The operational condition of the vehicle and speed of the vehicle may be determined when a request or input for operating the HVAC unit (200) is received by the ECU (7), for regulating temperature in the cabin of the vehicle. Further, the ECU (7) may selectively operate the compressor (1) based on the operational condition of the vehicle and the speed of the vehicle.
For example, when the speed of the vehicle is zero [that is, vehicle is at halt or standstill] with operational condition of the vehicle may either be the electric mode or the hybrid mode, and a request for operating the HVAC unit (200) may be received by the ECU (7), then the ECU (7) may be configured to operate an actuation unit (12) to disengage the traction motor (4) from the output shaft of the transmission (3). The traction motor (4) on disengagement with the transmission (3) may drive the compressor (1) of the HVAC unit (200), via the power transmission unit (6). With such operation, the ECU (7) may be configured to mitigate operation of the engine (2), whereby reducing fuel consumption and also, eliminating wear off of components in the transmission (3) and/or the engine (2). Additionally, for operating of the compressor (1), the traction motor (4) may derive power from a power source (11) coupled thereto, where the ECU (7) may be configured to monitor a state of charge of the power source (11), by one or more signal from the battery management unit (8) in the vehicle. The ECU (7) may further compare the state of charge of the power source (11) with a predetermined operational limit set therein, so that the ECU (7) may operate the engine (2) in an idle mode, to

energize the power source (11), when state of the charge in the power source (11) falls below the predetermined operational limit. The idle mode of the engine (2) may be referred to as a condition of the powertrain where, an output shaft of the engine (2) may be disconnected from the transmission (3) [that is, no power is supplied to the transmission (3) from the engine (2)]. In an embodiment, the clutch arrangement (15) between the engine (2) and the transmission (3) may be de-coupled to disconnect the engine (2) and the transmission (3) for operating the engine (2) in the idle mode. Also, the engine (2) may be configured to energize the power source (11) via a generator (5) of start-stop module coupled to the engine (2) and the power source (11), where rotation motion produced by the engine (2) may be converted to electrical energy by the generator (5), for energizing the power source (11). During energizing of the power source (11), the ECU (7) may operate the engine (2) at a predetermined rpm, for optimizing rate of energizing of the power source (11) and fuel consumption. The ECU (7) may further turn-off the engine (2), when the state of charge of the power source (11) may be equal to or at a defined value greater than the predetermined operational limit so that, consumption of fuel by the engine (2) may be mitigated.
In another example where, the speed of the vehicle is non-zero [that is, vehicle is mobile and not at standstill] and operational condition of the vehicle may be the electric mode [that is, the traction motor (4) is engaged or connected to the output shaft of the transmission (3), via the actuation unit (12), for mobility of the vehicle], and request for operating the HVAC unit (200) may be received by the ECU (7). At this juncture, the ECU (7) may be configured to operate the actuation unit (12) to continue engagement of the traction motor (4) with the output shaft of the transmission (3). In an embodiment, the actuation unit (12) may be a first clutch, which may selectively disengage the transmission (3) and the traction motor (4). With such configuration, the second clutch (13) may be operated to connect the compressor (1) and the power transmission unit (6) such that, the compressor (1) and in-turn the HVAC unit (200) may be operated by the traction motor (4) via the power transmission unit (6), along with operating the transmission (3) of the vehicle. Also, when the operational condition of the vehicle may be the hybrid mode [that is, mobility of the vehicle is imparted by both the traction motor (1) and the engine (2)], then the ECU (7) may be configured to operate the actuation unit (12) to couple the traction motor (4) with the output shaft of the transmission (3) so that, the traction motor (4)

may transmit power to the transmission (3) and operate the compressor (1) of the HVAC unit (200), simultaneously. Additionally, during movement of the vehicle in the hybrid mode and the electric mode, the ECU (7) may be configured to monitor the state of charge of the power source (11) such that, the generator (5) of start-stop module (9) may be selectively operated to energize the power source (11), when the state of charge falls below the predetermined operational limit. With such configuration, the ECU (7) may ensure that the state of charge of the power source (11) may be maintained at an optimum state, whereby reducing requirement of replacement and/or servicing of the power source (11). Also, when the vehicle may be operated in the engine mode [that is, the engine (2) is connected to the transmission (3) through the clutch arrangement (15) for mobility of the vehicle], then the actuation unit (12) may be operated by the ECU (7) to disconnect the traction motor (4) and transmission (3) to compressor (1) through actuation unit (12), power transmission unit (6), and second clutch (13) whereby transmitting power from the output shaft of the transmission (3) to the compressor (1). Also when vehicle may be operating in regeneration mode [that is, the wheels (not shown in figure) drive the traction motor for recuperation of the energy] or when state of charge of the power source (11) is at optimum state making regeneration not possible or when vehicle may be coasting down, then the ECU (7) may be configured to operate the actuation unit (12) to couple the traction motor (4) with the output shaft of the transmission (3), so that wheels can operate the compressor (1) of HVAC unit (200) through differential (not shown), output shaft of the transmission (3), actuation unit (12), power transmission unit (6), and second clutch (13) along with driving the traction motor (3).
In an embodiment, the actuation unit (12) may also be an epicyclic gear assembly, as best seen in Figure 2. The epicyclic gear assembly may include a plurality of gear sets selectively meshed with one another and a brake assembly to regulate speed transmitted therethrough. Further, the epicyclic gear assembly may be configured such that, rotational input [also known as torque input] may be selectively amplified based on gear ratio therein. The epicyclic gear assembly may receive torque input from the traction motor (4), where torque input from the traction motor (4) may be amplified by the epicyclic gear assembly so that, adequate power may be delivered to the transmission (3) and in-turn wheels of the vehicle, during operation of the vehicle in the electric mode. The brake assembly in the epicyclic gear assembly may be configured to

selectively regulate power received from the traction motor (4) based on gear ratio such that, power derived from the power source (11), by the traction motor (4), may be reduce for imparting mobility and/or enhancing speed of the vehicle.
In an embodiment, speed of the vehicle may be determined by the ECU (7) based on the speed sensor (10) or a transmission module [now shown in figures] associated with the transmission (3), where the speed sensor (10) may be coupled to at least one of a gear in the differential, wheel axel from differential, wheel of the vehicle, and any other component in the vehicle that may suggest in speed of the vehicle.
In an embodiment, the auto start-stop module (9) includes the generator (5) connected to the engine (2) through a belt drive assembly. Further, the generator (5) of start-stop module (9) is coupled to the power source (11), where rotation motion produced by the engine (2) may be converted to electrical energy by the generator (5), for energizing the power source (11). Also, the auto start-stop module (9) may be configured to enable the ECU (7) in selectively operating the actuation unit (12) and the generator (5), for suitably driving the compressor (1) either by the engine (2) or the traction motor (4). The generator (5) of start-stop module (9) may act as a motor to perform hybrid vehicle functions like engine start-stop, recuperation, and torque assist.
In an embodiment, the power source (11) may be a DC battery.
In an embodiment, the ECU (7) may be a centralized control unit of the vehicle or may be a dedicated control unit to the system (100) associated with the centralized control unit of the vehicle. The ECU (7) may also be associated with other control units including, but not limited to, body control unit, engine (2) control unit, and the like. The ECU (7) may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing program components for executing user- or system (100)-generated requests. The processing unit may be a specialized processing unit such as integrated system (100) (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron or other line of processors, etc. The processing unit may be

implemented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc.
The ECU (7) may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory devices including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fiber channel, small computing system (100) interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, redundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.
Referring now to Figure 3 which is an exemplary embodiment of the present disclosure illustrating a flow chart of a method for operating a compressor (1) of a Heating, Ventilating and Air conditioning (HVAC) unit (200) in a hybrid vehicle. In an embodiment, the method may be implemented in any hybrid vehicle including, but not limited to, a cars, trucks, and the like.
The method may describe in the general context of processor executable instructions in the ECU (7). Generally, the executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.
The order in which the method 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 scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.
At block 301, the ECU (7) may be configured to determine operation condition of the vehicle which may be at least one of the electric mode, the engine mode and the hybrid mode. When

the vehicle is operated in the electric mode, then the engine (2) may be disconnected from the transmission (3) while, the traction motor (4) may be connected to the transmission (3) for driving the vehicle. Additionally, when the vehicle is operated in the hybrid mode, then both the engine (2) and the traction motor (4) may be connected with the transmission (3) for driving the vehicle. With the engine (2) mode and the hybrid mode, power from traction motor (4) is derived for operating the compressor (1) of the HVAC unit (200), whereby reducing fuel consumption of the engine (2) during operation of the HVAC unit (200).
Further, on determining operating condition of the vehicle, the ECU (7) may be configured to determine speed of the vehicle, as at block 302. The speed of the vehicle may be determined by the speed sensor (10) associated with at least one of the transmission (3) and wheels of the vehicle, where the speed sensor (10) may be configured to indicate either zero speed of the vehicle or motion of the vehicle, to the ECU (7). Based on speed of the vehicle ECU (7) may be configured to determine state of the vehicle either standstill or running, as at block 303.
The ECU (7), upon determining that the speed of the vehicle to be zero and that the vehicle is operated in the electric mode or the hybrid mode, is configured to operate the actuation unit (12), as at block 304. The actuation unit (12) may be operated to disconnect the traction motor (4) from the transmission (3) so that, the compressor (1) is driven by the traction motor (4) and no power is derived from the engine (2) for operating the compressor (1).
In an embodiment, as the traction motor (4) may derive power from a power source (11) to operate the compressor (1), the ECU (7) may be configured to monitor the state of charge of the power source (11), through the battery management unit (8). The ECU (7) may compare the state of charge of the power source (11) with a predetermined operational limit set in the battery management unit (8), so that the ECU (7) may operate the engine (2) in an idle mode, to energize the power source (11), when state of the charge in the power source (11) falls below the predetermined operational limit. Also, the engine (2) may be configured to energize the power source (11) via a generator (5) of start-stop module (9) coupled to the engine (2) and the power source (11), where rotation motion produced by the engine (2) may be converted to electrical energy by the generator (5), for energizing the power source (11). The ECU (7) may further turn-off the engine (2), when the state of charge of the power source (11) may be equal

to or at a defined value greater than the predetermined operational limit so that, consumption of fuel by the engine (2) may be mitigated.
In an embodiment, the method and the system reduces fuel consumption by the engine (2) in operating the compressor (1) of the HVAC unit (200), during operation of the vehicle in either of the electric mode and the hybrid mode, when the vehicle may be at halt or during mobility.
In an embodiment, the system may be configured to operate the HVAC unit (200) even when the vehicle tends to move from halt, and when being operated in either the electric mode or the hybrid mode.
In an embodiment, the system may be configured to re-energize the power source (11) in real-time based on signals from the battery management unit (8), whereby mitigating necessity for regular maintenance or replacement of the power source (11).
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 (100) 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 (100) 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.”
In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
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.

Particular Numeral
Compressor 1
Engine 2
Transmission 3
Traction motor 4
Generator 5
Power transmission unit 6
ECU 7
Battery management unit 8
Start-Stop module 9
Speed sensor 10
Power source 11
Actuation unit 12
Second clutch 13
Driving mechanism 14
Clutch arrangement 15
System 100
HVAC unit 200

We claim:
1. A system (100) for operating a compressor (1) of a Heating, Ventilating and Air
conditioning (HVAC) unit (200) in a hybrid vehicle, wherein a powertrain configuration
of the hybrid vehicle comprises an engine (2), a transmission (3) coupled to the engine (2),
and a traction motor (4) coupled to an output shaft of the transmission (3), the system (100)
comprising:
a power transmission unit (6) coupling the compressor (1) to an output shaft of the traction motor (4); and
an electronic control unit (200) (ECU) (7), communicatively coupled to a battery management unit (8), the engine (2), the traction motor (4), an auto start-stop module (9) associated with the engine (2), and a speed sensor (10), wherein the electronic control unit (200) is configured to:
determine, operational condition of the vehicle, wherein the vehicle is
operable in at least one of an electric mode, a hybrid mode, and an engine mode;
determine, speed of the vehicle based on a signal received from the speed sensor (10); and
operate, an actuation unit (12), to disengage the traction motor (4) from the output shaft of the transmission (3), upon receiving a signal to operate the HVAC unit (200) of the vehicle, when the speed of the vehicle is determined to be zero in the hybrid mode and the electric mode of operation of the vehicle, such that the traction motor (4) drives the compressor (1) of the HVAC unit (200).
2. The system (100) as claimed in claim 1,wherein the ECU (7) is configured to monitor state of charge of a power source (11) coupled to the traction motor (4), when the traction motor (4) is driving the compressor (1) of the HAVC unit (200), and when the speed of the vehicle is zero in the hybrid mode and the electric mode of operation of the vehicle.
3. The system (100) as claimed in claim 2, wherein the ECU (7) is configured to operate the engine (2) in an idle mode, to energize the power source (11), when the state of the charge in the power source (11) falls below a predetermined operational limit.

4. The system (100) as claimed in claim 3, wherein the engine (2) is operated in the idle mode by disconnecting an output shaft of the engine (2), from the transmission (3).
5. The system (100) as claimed in claim 4, wherein the engine (2) is coupled to the transmission (3) through a clutch arrangement (15), for selectively operating the engine (2) in the idle mode.
6. The system (100) as claimed in claim 3, wherein, the power source (11) is energized by operating a generator (5) coupled to the engine (2).
7. The system (100) as claimed in claim 1, wherein the traction motor (4) is coupled to the output shaft of the transmission (3) through at least one of a first clutch and an epicyclic gear assembly.
8. The system (100) as claimed in claim 1, wherein the compressor (1) is coupled to the power transmission unit (6) through a second clutch (13).
9. The system (100) as claimed in claim 1, wherein the power transmission unit (6) is at least one of a belt drive, a gear drive and a chain drive.
10. A method for operating a compressor (1) of a Heating, Ventilating and Air conditioning (HVAC) unit (200) in a hybrid vehicle, wherein a powertrain configuration of the hybrid vehicle comprises an engine (2), a transmission (3) coupled to the engine (2), and a traction motor (4) coupled to an output shaft of the transmission (3), and wherein the compressor (1) is coupled to an output shaft of the traction motor (4) through a power transmission unit (6), the method comprising:
determining, by an electronic control unit (ECU) (7), an operational condition of the vehicle, wherein the vehicle is operable in at least one of an electric mode, a hybrid mode, and an engine mode;
determining, by the ECU (7), speed of the vehicle based on a signal received from the speed sensor (10); and
operating, by the ECU (7), an actuation unit (12) to disengage the traction motor (4) from the output shaft of the transmission (3), upon receiving a signal to operate the

HVAC unit (200) of the vehicle, when the speed of the vehicle is determined to be zero in the hybrid mode and the electric mode of operation of the vehicle, such that the traction motor (4) drives the compressor (1) of the HVAC unit (200).
11. The method as claimed in claim 10, comprises monitoring, by the ECU (7), state of charge of a power source (11) coupled to the traction motor (4), when the traction motor (4) is driving the compressor (1) of the HAVC unit (200), and when the speed of the vehicle is zero in the hybrid mode and the electric mode of operation of the vehicle.
12. The method as claimed in claim 10, wherein operating, by the ECU (7), the engine (2) in an idle mode to energize the power source (11), when state of the charge in the power source (11) falls below a predetermined operational limit.
13. A vehicle comprising a system (100), as claimed in claim 1.