ELECTRIFYED DRIVETRAIN FOR A VEHICLE

Abstract

Electrified powertrain (10) for one vehicle (100), comprising: a first electric machine (12), a second electric machine (14), a coupling (36), a coolant circuit (32), an HVAC (heating, ventilation and air conditioning) compressor (34) and a control system (50); wherein the second electric machine (14) is rotary-coupled to a gear train (30); wherein the first electric machine (12) is rotary-coupled with the HVAC compressor (34) and can be rotary-coupled with the transmission train (30) via the coupling (36); wherein the coupling (36) can be operated in a first state and in a second state; wherein the first electric machine (12) is rotary-coupled to the transmission train (30) when the clutch (36) is controlled to the first state; wherein the first electric machine (12) is decoupled from the transmission train (30) when the clutch (36) is controlled into the second state; wherein the control unit (50) is operationally connected to the first and second electric machine (12, 14), the coupling (36) and the HVAC compressor (34) to control the operation of the electrified drive train (10); further comprising a coolant circuit (32) with a first cooling jacket (16) which is in thermal contact with the first electric machine (12), a cabin heat exchanger (18) and a second cooling jacket (46) which is in thermal contact with a DC power source (44); wherein the control (50) can be operated in such a way as to control the first electric machine (12) so that thermal energy is generated which can be recovered through the coolant circuit (32) when the first electric machine (12) is operated in a regenerative braking state, while the second electric machine (14) is operated to generate a traction torque.

Description

INTRODUCTION

[0001] Vehicles with electrified powertrains require onboard equipment to provide additional functions, such as HVAC (heating, ventilation, and air conditioning) units with air conditioning compressors and heater cores. In internal combustion engine vehicles, these functions are provided by auxiliary components driven by auxiliary drive belts and coolant circuits, including radiators and other heat exchangers. In an electrified vehicle, coolant circuits and belt-driven auxiliary components can be eliminated, and these functions can be performed by standalone systems, such as a separate electric motor driving an air conditioning compressor and an electrically driven heater. Such standalone systems consume space, increase wiring complexity, add weight to the vehicle, and incur additional costs.

[0002] DE 11 2011 102 477 T5 describes a drive device for an electric vehicle, which has an output part that is connected to wheels in a driving manner and a compressor connection part that is connected to a compressor for an air conditioning system and which generates a driving force to be transmitted to the output part and the compressor connection part by means of a rotating electric machine.

[0003] DE 11 2011 102 566 T5 describes an electric vehicle drive system comprising an output component coupled to a wheel for drive purposes and a compressor connection component coupled to a compressor for an air conditioning system, wherein a drive power to be transferred to the output component and the compressor connection component is generated by a rotating electric machine.

[0004] DE 10 2017 223 114 A1 describes a method for the targeted heating of an electric vehicle. The actual temperature value in the electric vehicle is recorded and compared with a target temperature value. Furthermore, a heating device for an electric vehicle is described, which is designed to carry out the method.

[0005] DE 10 2009 031 645 A1 describes a drive unit for an electric vehicle in which at least one wheel is driven by an electric motor. The electric vehicle could, for example, be an electrically powered passenger car. SUMMARY

[0006] The concepts described here provide a creative arrangement of an electrified powertrain for a vehicle. According to the invention, an electrified powertrain for a vehicle is provided, comprising a first electric machine, a second electric machine, a coupling, an HVAC compressor, and a control unit. The second electric machine is rotary-coupled to a transmission, the first electric machine is rotary-coupled to the HVAC compressor and can be rotary-coupled to the transmission via the coupling, and the coupling can be operated in a first state and a second state.

[0007] The first electric motor is rotaryally coupled to the gear wheel when the clutch is engaged in the first state and is disengaged from the transmission when the clutch is engaged in the second state. The control unit is operationally linked to the first and second electric motors, the clutch, and the HVAC compressor to manage the operation of the electrified powertrain.The electrified powertrain further comprises a coolant circuit with a first cooling jacket in thermal contact with the first electric machine, a cabin heat exchanger and a second cooling jacket in thermal contact with a DC power source, wherein the control can be operated to control the first electric machine in such a way as to generate thermal energy which can be recovered through the coolant circuit when the first electric machine is operated in a regenerative braking state while the second electric machine is operated to generate traction torque.

[0008] One aspect of the revelation includes that the first electric machine is rotary-coupled to the transmission train via the second electric machine when the coupling is controlled into the first state.

[0009] Another aspect of the revelation includes that the first electric machine is directly rotatably coupled to the transmission train when the clutch is controlled into the first state.

[0010] Another aspect of the revelation includes that the controller controls the first electric machine and an HVAC coupling to operate the HVAC compressor.

[0011] Another aspect of the revelation includes the fact that the control system drives the first electric machine in such a way that it generates a traction torque which is transferred to the drive train.

[0012] Another aspect of the disclosure includes a coolant circuit comprising a first cooling jacket in thermal contact with the first electric machine, a cabin heat exchanger, and a second cooling jacket in thermal contact with the DC power source, wherein the control can be operated to control the first electric machine to generate thermal energy that can be recovered through the coolant circuit.

[0013] Another aspect of the revelation includes the fact that the control system can be operated in such a way as to control the first electrical machine so that it generates thermal energy which can be recovered through the coolant circuit.

[0014] Another aspect of the revelation includes the fact that the control system directs the first electric machine to operate the HVAC compressor and generate a traction torque that is transferred to the drivetrain.

[0015] Another aspect of the revelation includes the fact that the control system directs the first electric machine to operate the HVAC compressor and generate thermal energy that can be recovered through the coolant circuit.

[0016] Another aspect of the revelation includes the fact that the control system controls the first electric machine in such a way that it generates a traction torque which is transferred to the drive train, and that it generates thermal energy which can be recovered through the coolant circuit.

[0017] Another aspect of the revelation includes that the control system controls the first electric machine to operate the HVAC compressor and generate a traction torque that is transferred to the drivetrain, and that it generates thermal energy that can be recovered through the coolant circuit.

[0018] Another aspect of the revelation includes the fact that the control system controls the first electric machine in an idle state.

[0019] The above features and advantages, as well as other features and advantages of the present teaching, are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the present teaching, as defined in the attached claims, when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are now described by way of example with reference to the attached drawing, in which: Fig. Figure 1 schematically shows an embodiment of an electrified powertrain for a vehicle, according to the disclosure.

[0021] It should be understood that the accompanying drawings are not necessarily to scale and represent a somewhat simplified depiction of various preferred features of the present disclosure as disclosed herein, including, for example, certain dimensions, orientations, positions, and shapes. Details associated with such features are partly determined by the specific intended application and operating environment. DETAILED DESCRIPTION

[0022] The components of the disclosed embodiments, as described and illustrated herein, can be arranged and implemented in a multitude of different configurations. Therefore, the following detailed description is not intended to limit the scope of the claimed disclosure, but is merely representative of possible embodiments thereof. Furthermore, while numerous specific details are included in the following description to facilitate a comprehensive understanding of the embodiments disclosed herein, some embodiments can also be implemented without some of these details. In addition, for the sake of clarity, a detailed description of certain technical matters that are self-evident in the related field has been omitted in order to avoid unnecessarily obscuring the disclosure.For the sake of simplicity and clarity only, directional terms such as above, below, left, right, over, above, under, behind, and in front are used in the drawings. These and similar directional terms are not to be interpreted as limiting the scope of the disclosure. Moreover, the disclosure, as presented and described herein, can be carried out even without any element not specifically disclosed herein. Furthermore, there is no intention of being bound by any express or implied theory presented in the preceding technical section, background, brief summary, or subsequent detailed description. It should also be understood that in the drawings, corresponding reference numbers point to identical or equivalent parts and features.The terms "first," "second," and the like are used to distinguish similar elements and do not denote order, quantity, priority, or importance. The terms "a" and "an," and the like, are used to indicate the presence of at least one of the referenced elements and do not denote quantity.

[0023] Referring to the drawing, it shows Fig. Figure 1 schematically shows an embodiment of an electrified powertrain 10 for a vehicle 100. The vehicle 100 may comprise, but is not limited to, a mobile platform in the form of a commercial vehicle, an industrial vehicle, an agricultural vehicle, a passenger car, an aircraft, a watercraft, a train, an all-terrain vehicle, a personal mobility device, a robot, and the like, in order to fulfill the purposes of this disclosure.

[0024] The electrified powertrain 10 is mechanically rotary-coupled to a gearbox 30 to transmit mechanical power to one or more drive wheels 20 of the vehicle 100, and its operation is monitored and controlled by a controller 50. The controller 50 can be configured as a single controller or, alternatively, as a plurality of controllers arranged to monitor sensor inputs and execute algorithms to control actuators in response to operator commands. The electrical power is supplied by a high-voltage electrical system 40, which includes a DC power source 44 and a high-voltage bus 42.

[0025] The electrified drive train 10 comprises a first electric machine 12 and a second electric machine 14, wherein the second electric machine 14 is rotaryally coupled to the drive train 30 and the first electric machine 12 can be rotaryally coupled to the second electric machine 14 via the activation of the coupling C1 36 (represented by a solid line), or alternatively, the first electric machine 12 can be rotaryally coupled to the drive train 30 via the activation of the coupling C1 36 (represented by a dashed line). The coupling C1 36 can be operated in either a first state or a second state. When the coupling C1 36 is controlled in the first state, the first electric machine 12 is rotaryally coupled to the second electric machine 14. When the coupling C1 36 is controlled in the second state, the first electric machine 12 is decoupled from the second electric machine 14.In the alternative embodiment, when the clutch C1 36 is controlled to the first state, the first electric machine 12 is directly rotary-coupled to the gearbox 30, and when the clutch C1 36 is controlled to the second state, the first electric machine 12 is rotary-decoupled from the gearbox 30 and thus decoupled from the second electric machine 14.

[0026] The transmission train 30 comprises one or a combination of single gears, interlocking gears, differential gears, clutches, pulleys, chain drives, etc., arranged to enable speed and / or torque conversion between the first and second electric machines 12, 14 and a drive shaft 38.

[0027] The drive shaft 38 is arranged to transmit the traction torque between the transmission 30 and the drive wheel(s) 20 via an axle, differential, or other device. The drive shaft 38 can be arranged in a single-wheel configuration, a front-wheel drive configuration, a rear-wheel drive configuration, a four-wheel drive configuration, an all-wheel drive configuration, or another suitable configuration. The drive shaft 38 is configured to transmit the traction force between the first and / or second electric machine 12, 14, the transmission 30, and a road surface via the drive wheel(s) 20. The drive shaft 38 is for illustrative purposes only, and the concepts described here also apply to other drivetrain systems.

[0028] The first and second electric machines 12, 14 are configured as multiphase electric motors / generators and can comprise any motor / generator device capable of operating as a motor to generate torque or as a generator to produce electrical energy. For example, the first and second electric machines 12, 14 can be configured as multiphase brushless electric motor-generators or similar devices. In one embodiment, the second electric machine 14 is arranged to provide traction power for vehicle propulsion. In another embodiment, the first electric machine 12 is sized to provide auxiliary power. The first and second electric machines 12, 14 are electrically connected to appropriate inverters (not shown), which can be integrated or stand-alone devices.Each inverter can be configured with a controller and control circuitry that includes power transistors, such as integrated-gate bipolar transistors (IGBTs), for direct current (DC) to alternating current (AC) and AC to DC conversion. The controller can use pulse-width modulation (PWM) control of the IGBTs to convert stored DC electrical current from the DC power source 44 into AC electrical current to drive the respective first or second electric machine 12, 14 and generate torque. Similarly, the controller can use PWM control of the IGBTs to convert mechanical load applied to the respective first or second electric machine 12, 14 into DC electrical current to generate electrical energy that can be stored in the DC power source 44, also as part of a regenerative braking control strategy.The inverter's control unit receives motor control commands from the controller 50 and controls inverter states to achieve the desired motor drive operation or regenerative braking operation. The generated electrical energy can be stored in the DC power source 44 or supplied as current to power an electrical auxiliary system, such as a radiant heat exchanger. The first and second electrical machines 12, 14 can include other electrical devices, such as one or more motor position sensors, a temperature sensor, a current sensor, a voltage sensor, etc. The first and second electrical machines 12, 14 can include thermal management components to cool the first and second electrical machines 12, 14 and the electrical components, etc.In one embodiment, the thermal management components can comprise a first cooling jacket 16 arranged around an outer casing of the stator of the first electric machine 12.

[0029] The DC power source 44 is arranged to supply electrical current at a suitable voltage level and may, for example, comprise a multi-cell lithium-ion device, an ultracapacitor, or another device. Monitored parameters relating to the DC power source 44 may include the state of charge (SOC), the device temperature, etc. In one embodiment, the DC power source 44 can be electrically connected to a remote, external power source via a vehicle battery charger to charge the vehicle while stationary. The DC power source 44 may, in one embodiment, be configured with a nominal DC voltage level of 48 volts. Alternatively, the DC power source 44 may be configured with a nominal DC voltage level of 300 volts or another suitable voltage level, as may be selected.

[0030] The components of the thermal management system are elements of a coolant circuit 32, which in one embodiment comprises the first cooling jacket 16, which is in thermal contact with the first electric machine 12, a cabin heat exchanger 18, and a second cooling jacket 46, which is in thermal contact with the DC power source 44. The first cooling jacket 16 is fluidically connected to the cabin heat exchanger 18 and the second cooling jacket 46, which is arranged at the DC power source 44, via a fluidic coolant circuit 32. In one embodiment, the fluidic coolant circuit 32 comprises a fluidic pump 26 and a reservoir for circulating the fluidic coolant therein.

[0031] The first electric machine 12 is rotaryally coupled to an HVAC compressor 34 and can be rotaryally coupled to the transmission train 30 either directly or alternatively via the second electric machine 14 via the coupling 36. The HVAC compressor 34 is an element of an HVAC system 35 and is designed in one embodiment as a mechanical scroll compressor or in another possible embodiment as a piston compressor. The operation of the HVAC compressor 34 is controlled via a controllable coupling 33, which is controlled by the controller 50. The HVAC compressor 34 is rotatably coupled to the first electric machine 12 via a rotatable shaft, a gear drive, a belt drive, or another torque transmission device.

[0032] The controller 50 can communicate with an operator interface (not shown) and serves for the hierarchical control of a variety of control devices to effect the operational control of individual elements, including, for example, the first and second electric machines 12, 14, the DC power source 44, the coupling C1 36, and the HVAC coupling 33, either directly or via a communication bus to monitor and control their operation. The first electric machine 12 can be a multi-purpose electric motor that can be used as a traction motor coupled to the drive train 38, as a compressor motor coupled to the HVAC compressor 34, and as an electric heating device via the coolant circuit 32, either simultaneously, individually, or in any combination.

[0033] The control unit 50 is operationally connected to the first and second electric machines 12, 14, the coupling 36 and the HVAC coupling 33 to control the operation of the electrified drive train 10 depending on specified conditions.

[0034] The control unit 50 controls the first electric machine 12 so that it generates a torque and activates the HVAC coupling 33 so that the HVAC compressor 34 is operated under a predetermined condition.

[0035] The control unit 50 controls the first electric machine 12 so that it generates a torque which is transmitted via the drive train 30 to the drive shaft 38 under a predetermined condition.

[0036] The control unit 50 controls the first electric machine 12 so that it generates thermal energy under a prescribed condition, which can be recovered through the coolant circuit 32. This can include, as non-limiting examples, the operation of the first electric machine 12 under suboptimal electrical flow conditions, the operation of the compressor in an idle state, and the control of the first electric machine 12 in a regenerative braking state while the second electric machine 14 is operated to generate a traction torque.

[0037] The control unit 50, by activating the HVAC coupling 33, controls the first electric machine 12 so that it drives the HVAC compressor 34 and simultaneously controls the second electric machine 14 so that it generates a traction torque which is transmitted via the transmission 30 to the drive shaft 38 under a predetermined condition.

[0038] The control unit 50 controls the first electric machine 12 by activating the HVAC coupling 33 so that it drives the HVAC compressor 34 and simultaneously controls the first electric machine 12 so that it generates thermal energy which can be recovered through the coolant circuit 32 under a prescribed condition.

[0039] The control unit 50 controls the second electric machine 14 so that it generates a torque which is transmitted via the gear train 30 to the drive shaft 38, and simultaneously controls the first electric machine 12 so that it generates thermal energy which can be recovered under a given condition through the coolant circuit 32.

[0040] The control unit 50, by activating the HVAC clutch 33, controls the first electric machine 12 to drive the HVAC compressor 34, simultaneously controls the first electric machine 12 to generate a traction torque that is transmitted to the drive shaft 38 via the transmission 30, and simultaneously controls the first electric machine 12 to generate thermal energy that can be recovered through the coolant circuit 32 under a predetermined condition. In this way, the control unit 50 mediates between a requirement for traction force, a requirement for thermal heat generation in the cabin, and a requirement for compressor operation, e.g., for defrosting. It also mediates between the first and second electric machines 12, 14 to provide the vehicle's traction force in a manner that optimizes system efficiency.

[0041] The control unit 50 controls the first electric machine 12 in the free-running state under a predetermined condition, whereby the entire mechanical torque for the drive shaft 38 and the HVAC compressor 34, including parasitic losses, is provided by the first electric machine 12.

[0042] A possible outcome of the configuration and control of the electrified powertrain 10 described here is an expected improvement in vehicle operating range at cold ambient temperatures as a result of improved component and system heating using regenerative braking energy that would otherwise be lost when the DC power source 44 is in a high state of charge (SOC). This includes operating the first electric machine 12 as a heat pump to provide cabin heating. Furthermore, when the vehicle 100 is in an auto-stop state, the first clutch 36 can be controlled to the first state, and the current flow from the first electric machine 12 is controlled so that it becomes a heating element, transferring the heat to the coolant circuit 32.When the vehicle 100 is operated with the DC power source 44 at a high state of charge (SOC) under cold ambient temperature conditions, the second electric machine 14 is controlled to recover energy that would otherwise be wasted. Another possible result of the configuration and control of the electrified powertrain 10, as described here, includes an expected improvement in the vehicle's operating range at mild ambient temperatures.

[0043] The term "controller" and related terms such as microcontroller, control module, module, controller, control unit, processor and similar terms refer to one or more combinations of application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), electronic circuits, central processing units, e.g. microprocessors and associated non-transient memory components in the form of storage and memory devices (read-only, programmable read-only, random access, hard disk drive, etc.).The non-transitory memory component is capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuits, input / output circuits and devices, signal conditioning, buffer circuits, and other components that can be accessed and executed by one or more processors to provide a described functionality. Input / output circuits and devices include analog-to-digital converters and related devices that monitor sensor inputs, either at a preset sampling rate or in response to a triggering event. Software, firmware, programs, instructions, control routines, code, algorithms, and similar terms refer to sets of instructions executable by controllers, including calibrations and lookup tables.Each controller executes control routine(s) to provide desired functions. These routines can be executed at regular intervals, for example, every 100 microseconds during operation. Alternatively, they can be executed in response to a triggering event. Communication between controllers, actuators, and / or sensors can occur via a directly wired point-to-point connection, a networked communication bus connection, a wireless connection, or another suitable communication link. This communication involves the exchange of data signals in a suitable form, such as electrical signals over a conductive medium, electromagnetic signals over air, optical signals over fiber optics, and the like. The data signals can include discrete analog or digitized analog signals representing sensor inputs, actuator commands, and communication between controllers.

[0044] The term "signal" refers to a physically perceptible indicator that transmits information and can be a suitable waveform (e.g., electrical, optical, magnetic, mechanical, or electromagnetic), such as direct current, alternating current, sine wave, triangle wave, square wave, vibration, and the like, which can propagate through a medium.

[0045] A parameter is defined as a measurable quantity that represents a physical property of a device or other element, detectable by one or more sensors and / or a physical model. A parameter can have a discrete value, e.g., either "1" or "0", or it can have a continuously variable value.

[0046] The detailed description and the drawings or figures are supporting and descriptive of the present teaching, but the scope of the present teaching is defined exclusively by the claims. While some of the best modes and other embodiments for carrying out the present teaching have been described in detail, various alternative designs and embodiments exist for implementing the present teaching as defined in the appended claims.

Claims

[1] Electrified powertrain (10) for a vehicle (100), comprising: a first electric machine (12), a second electric machine (14), a coupling (36), a coolant circuit (32), an HVAC (heating, ventilation and air conditioning) compressor (34) and a control system (50); wherein the second electric machine (14) is rotary-coupled to a gear train (30); wherein the first electric machine (12) is rotary-coupled with the HVAC compressor (34) and can be rotary-coupled with the transmission train (30) via the coupling (36); wherein the coupling (36) can be operated in a first state and in a second state; wherein the first electric machine (12) is rotary-coupled to the transmission train (30) when the clutch (36) is controlled to the first state; wherein the first electric machine (12) is decoupled from the transmission train (30) when the clutch (36) is controlled into the second state; wherein the control unit (50) is operationally connected to the first and second electric machine (12, 14), the coupling (36) and the HVAC compressor (34) to control the operation of the electrified drive train (10); further comprising a coolant circuit (32) with a first cooling jacket (16) which is in thermal contact with the first electric machine (12), a cabin heat exchanger (18) and a second cooling jacket (46) which is in thermal contact with a DC power source (44); wherein the control (50) can be operated in such a way as to control the first electric machine (12) so that thermal energy is generated which can be recovered through the coolant circuit (32) when the first electric machine (12) is operated in a regenerative braking state, while the second electric machine (14) is operated to generate a traction torque. [2] Electrified drive train (10) according to claim 1, wherein the first electric machine (12) is rotary-coupled to the transmission train (30) via the second electric machine (14) when the clutch (36) is controlled to the first state. [3] Electrified drive train (10) according to claim 1, wherein the first electric machine (12) is directly rotary-coupled to the transmission train (30) when the clutch (36) is controlled into the first state. [4] Electrified drive train (10) according to claim 1, wherein the control unit (50) controls the first electric machine (12) and an HVAC coupling (33) for operating the HVAC compressor (34). [5] Electrified drive train (10) according to claim 1, wherein the control unit (50) controls the first electric machine (12) such that it generates a traction torque which is transferred to the transmission train (30). [6] Electrified drive train according to claim 1, wherein the control can be operated such that it controls the first electric machine to operate the HVAC compressor in an idle state. [7] Electrified drive train (10) according to claim 1, wherein the control unit (50) controls the first electric machine (12) to operate the HVAC compressor (34) and generate a traction torque which is transferred to the transmission train (30). [8] Electrified powertrain (10) according to claim 1, wherein the control unit (50) controls the first electric machine (12) to operate the HVAC compressor (34) and generate thermal energy which can be recovered through the coolant circuit (32). [9] Electrified drive train (10) according to claim 1, wherein the control unit (50) controls the first electric machine (12) such that it generates a traction torque which is transferred to the transmission train (30) and that it generates thermal energy which can be recovered through the coolant circuit (32).

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