DESC:FAULT PROTECTION IN ELECTRIC POWERTRAIN
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202421024546 filed on 27/03/2024, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to an electric powertrain. Particularly, the present disclosure relates to a powertrain unit of an electric vehicle.
BACKGROUND
Recently, there has been a rapid development in the automotive technologies. The automobiles contain a propulsion system that propels the vehicle from one position to another by generating power and transferring the generated power to the wheels of the vehicle.
Conventionally, the drivetrain unit in an electric vehicle converts electrical energy stored in the battery pack in to drive the motor, propelling the vehicle forward. This process is controlled by the power electronics and motor controller, ensuring efficient energy transfer. However, during regenerative braking, the motor operates as a generator, converting kinetic energy back into electrical energy. This process induces a back electromotive force (back emf), which feeds power back into the battery, effectively recharging the battery. While back emf is beneficial for energy recovery, excessive back emf may leads to voltage spikes, needs careful regulation through the vehicle's power management system to optimize efficiency and battery longevity. Furthermore, to regulate excessive back emf generation during regenerative braking, various techniques are employed to ensure safe voltage levels and prevent damage to power electronics and batteries. One of the common technique is dynamic braking, where excess energy is dissipated as heat through resistors when the battery cannot absorb more charge. Another technique involves active power electronics, such as DC-DC converters, which regulate the voltage by controlling energy flow between the motor and the battery. Additionally, some systems utilize ultracapacitors to temporarily store excess energy and release the same stored energy when needed, reducing strain on the battery. Despite the advantages, these techniques have some limitations which includes the dynamic braking leads to energy wastage as heat, reducing overall efficiency of the vehicle. Furthermore, the power electronics require complex control algorithms and robust components, increasing system cost and design complexity. The ultracapacitors, while effective, adds the weight on the powertrain system and requires additional space which makes the integration challenging in compact vehicle architectures. Moreover, the efficiency of energy recovery is limited by factors such as battery state of charge, thermal constraints, and real-time power demand, preventing full utilization of regenerative braking potential.
Therefore, there is a need to provide an improved arrangement for powertrain unit to overcome the one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide a powertrain unit of an electric vehicle.
In accordance with an aspect of the present disclosure, there is provided a powertrain unit of an electric vehicle. The powertrain unit comprises a traction motor, a traction inverter, electrically connected to the traction motor and a control unit communicably coupled with the traction motor and the traction inverter. The traction motor comprises a protection module to protect the traction inverter during back emf generation by the traction motor.
The present disclosure provides the powertrain unit of the electric vehicle. The powertrain unit as disclosed by present disclosure is advantageous in terms of providing an enhanced protection, operational efficiency, and the reliability of the powertrain unit. Beneficially, the powertrain unit safeguards the traction inverter from potential damage caused by back electromotive force (emf) generated during motor operation. Beneficially, the powertrain unit actively monitors and regulates the back emf, preventing potential voltage spikes that may damage critical power electronics components. Beneficially, the powertrain unit enables dynamic isolation of the traction motor from the inverter when back emf exceeds a predefined safety threshold. Furthermore, the powertrain unit beneficially safeguards the inverter and also enhances overall powertrain efficiency by mitigating energy losses due to uncontrolled voltage fluctuations. Furthermore, the powertrain unit significantly ensures the real-time detection and response which allows seamless operation without manual intervention. Overall, the powertrain unit improves vehicle safety, efficiency, and durability, making an effective solution for managing regenerative energy and protecting power electronics in modern electric vehicles.
Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 illustrates a block diagram of a powertrain unit of an electric vehicle, in accordance with an aspect of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognise that other embodiments for carrying out or practising the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a powertrain unit of an electric vehicle and is not intended to represent the only forms that may be developed or utilised. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimised to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail 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 alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings and which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “electric vehicle”, “EV”, and “EVs” are used interchangeably and refer to any vehicle having stored electrical energy, including the vehicle capable of being charged from an external electrical power source. This may include vehicles having batteries which are exclusively charged from an external power source, as well as hybrid-vehicles which may include batteries capable of being at least partially recharged via an external power source. Additionally, it is to be understood that the ‘electric vehicle’ as used herein includes electric two-wheeler, electric three-wheeler, electric four-wheeler, electric pickup trucks, electric trucks and so forth.
As used herein, the term “powertrain unit” refers to an integrated assembly of components responsible for converting and delivering power to drive a vehicle. In electric vehicle, the powertrain unit typically includes a traction motor, a traction inverter, a control unit, and associated electrical or mechanical components that facilitate the efficient transfer of electrical energy from an energy source (e.g., battery or power pack) to mechanical motion. The powertrain unit may further incorporate protective systems, such as a protection module, to regulate operational parameters and safeguard components from electrical anomalies like excessive back emf.
As used herein, the term “traction motor” refers to a traction motor refers to an electric motor configured to generate mechanical torque for propelling a vehicle. The traction motor is operable to receive electrical energy from a power source, such as a battery or an external power supply, and convert the electrical energy into rotational motion to drive the vehicle’s wheels. Additionally, the traction motor may function as a generator during regenerative braking, converting kinetic energy into electrical energy for storage or reuse. The traction motor may be of various types, including but not limited to Permanent Magnet Synchronous Motors (PMSM), Induction Motors, or Switched Reluctance Motors (SRM), depending on the specific application and design of the vehicle’s powertrain system.
As used herein, the term “traction inverter” refers to an electronic power conversion device configured to control and regulate the electrical energy supplied to a traction motor in an electric vehicle. The traction inverter is electrically connected between a power source and the traction motor, wherein the traction inverter converts direct current (DC) from the power source into alternating current (AC) to drive the traction motor. Additionally, the traction inverter is configured to modulate the motor's speed, torque, and direction by adjusting the frequency and amplitude of the AC output.
As used herein, the term “control unit” refers to an electronic module configured to monitor, manage, and regulate various operational parameters of the powertrain unit. The control unit is responsible for coordinating the operation of the traction motor, traction inverter, and protection module. Its primary functions include monitoring, controlling, and optimizing power flow while ensuring safe and efficient operation of the drivetrain components. Based on the processed data, the control unit executes control algorithms to optimize the performance and safety of the system. Optionally, the control unit includes, but is not limited to, a microprocessor, a micro-controller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processing circuit. Furthermore, the term “processor” may refer to one or more individual processors, processing devices and various elements associated with a processing device that may be shared by other processing devices. Furthermore, the control unit may comprise ARM Cortex-M series processors, such as the Cortex-M4 or Cortex-M7, or any similar processor designed to handle real-time tasks with high performance and low power consumption. Furthermore, the control unit may comprise custom and/or proprietary processors.
As used herein, the term “communicably coupled” refers to a bi-directional connection between the various components of the system. The bi-directional connection between the various components of the system enables exchange of data between two or more components of the system. Similarly, bi-directional connection between the system and other elements/modules enables exchange of data between system and the other elements/modules.
As used herein, the term “protection module” refers to an electronic or electromechanical system integrated within the powertrain unit of an electric vehicle, configured to monitor, regulate, and mitigate the effects of excessive back electromotive force (back emf) generated by the traction motor. The protection module comprises one or more switching elements and associated components that selectively control electrical connectivity between the traction motor and the traction inverter.
As used herein, the term “back emf generation” refers to the phenomenon in which an electromotive force (emf) is induced in the windings of an electric motor when the motor operates in a generating mode or undergoes changes in rotational speed. The back emf occurs due to the relative motion between the magnetic field of the rotor and the stator windings, resulting in an induced voltage that opposes the applied voltage. In an electric vehicle powertrain, back emf generation primarily occurs during regenerative braking or sudden deceleration, where the traction motor acts as a generator and feeds electrical energy back into the system.
As used herein, the term “power pack”, “battery” and “battery pack” are used interchangeably and refer to source of electricity supply for charging of the electric vehicle. The power source may include wired AC power sources, wired DC power sources, wireless power sources, renewable energy-based power sources, non-renewable energy-based power sources and so forth.
As used herein, the term “star point” refers to a common electrical junction in a multi-phase motor, typically a three-phase motor, where the ends of all phase windings are connected together. This configuration is also known as a neutral point. The star point is not grounded and allows the star point to function as a floating node.
As used herein, the term “pair of switches” and “switches” are used interchangeably and refer to two electrically controllable switching elements that are configured to operate in coordination within a circuit. Each switch of the pair is capable of selectively opening or closing an electrical path based on a control signal. The pair of switches may be arranged in a series, parallel, or complementary configuration, depending on the functional requirements of the system. The switches may be implemented using semiconductor devices such as MOSFETs, IGBTs, or bidirectional-controlled switches, and may be operated independently or in synchronization to regulate current flow, voltage levels, or circuit protection.
As used herein, the term “predefined safety threshold” refers to a predetermined voltage or current limit set based on system design parameters, beyond which protective action is triggered to prevent potential damage to electrical components. The threshold value may be determined based on factors such as the rated operating voltage of the traction inverter, permissible back emf levels of the traction motor, thermal constraints, or regulatory safety standards.
As used herein, the term, “bidirectional -controlled switch” refers to an electronic switching device capable of selectively allowing or blocking current flow in both directions under the control of an external signal. The switch is configured to regulate bidirectional current conduction while providing controlled operation based on predefined conditions, such as voltage, current, or system requirements. The bidirectional-controlled switches typically comprises semiconductor components such as MOSFETs, IGBTs, TRIAC or wide-bandgap devices (SiC/GaN transistors), arranged in a topology that enables independent control of current flow in forward and reverse directions. The bidirectional-controlled switch may be employed in power electronics applications, including motor control, regenerative braking, battery management systems, and protection circuits, to ensure efficient energy transfer, mitigate voltage spikes, and enhance system safety.
Figure 1, in accordance with an embodiment describes a powertrain unit 100 of an electric vehicle. The powertrain unit 100 comprises a traction motor 102, a traction inverter 104, electrically connected to the traction motor 102 and a control unit 106 communicably coupled with the traction motor 102 and the traction inverter 104. The traction motor 102 comprises a protection module 108 to protect the traction inverter 104 during back emf generation by the traction motor 102.
The present disclosure provides the powertrain unit 100 of the electric vehicle. The powertrain unit 100 as disclosed by present disclosure is advantageous in terms of providing enhanced safety, reliability, and efficiency of the traction motor 102. Beneficially, the integration of the protection module 108 within the traction motor 102 provides a robust mechanism to safeguard the traction inverter 104 from excessive back emf generation, thereby preventing the potential damage to the power electronics. Furthermore, by utilizing the protection module 108 integrated with the star point 110, the powertrain unit 100 ensures a compact and efficient design, reducing additional wiring complexity and space requirements. Furthermore, the control unit 106 as disclosed by present disclosure is advantageous for actively monitoring the back emf levels and dynamically operates the pair of switches 112 adding an intelligent layer of control. Beneficially, the dynamic adjustment of the pair of switches 112 allows the real-time response to voltage fluctuations. Beneficially, the use of pair of switches 112 in the protection module 108 enables precise and efficient handling of bidirectional current flow, ensuring smooth operation in regenerative and motoring modes. Moreover, the ability of the control unit 106 to disconnect the traction motor 102 from the traction inverter 104 when back emf exceeds a predefined safety threshold beneficially prevents overvoltage stress, enhancing the longevity and operational reliability of the powertrain unit 100. Moreover, the provision to re-establish the connection when back emf is within safe limits significantly ensures the seamless power transmission without unnecessary interruptions proving self-recovery from the fault.
In an embodiment, the powertrain unit 100 comprises a power pack 108. The power pack 108 may be electrically connected to the traction inverter 104, which supplies controlled electrical power to the traction motor 102 for vehicle propulsion. The power pack 108 may include a battery pack, ultracapacitors, or a hybrid energy storage system. Beneficially, the integration of the power pack 108 within the powertrain unit 100 ensures optimized energy delivery for both motoring and regenerative braking operations.
In an embodiment, the traction motor 102 comprises a star point 110, wherein the protection module 108 is integrated with the star point 110 of the traction motor 102. The integration of the protection module 108 with the star point 110 allows efficient and centralized control of voltage levels across the motor windings, which ensures the balanced phase operation and optimized energy dissipation.
In an embodiment, the control unit 106 is communicably coupled with the protection module 108 to control the operation of the protection module 108. The control unit 106 continuously monitors the operating conditions of the traction motor 102 and detects the back emf levels. Based on predefined safety thresholds, the control unit 106 dynamically controls the protection module 108 to either allow or restrict electrical connection between the traction motor 102 and the traction inverter 104. Beneficially, the powertrain unit 100 ensures real-time protection of power electronics which significantly enhances the reliability and prevents the potential component failures caused by excessive voltage generation, thereby improving the overall performance and longevity of the electric vehicle powertrain unit 100.
In an embodiment, the protection module 108 comprises a pair of switches 112, wherein each switch of the pair of switches 112 is connected with a phase of the traction motor 102. Furthermore, the control unit 106 is configured to detect the back emf generation by the traction motor 102 and configured to determine whether the detected back emf exceeds a predefined safety threshold. Furthermore, the opening of the pair of switches 112 breaks electrical connection between the traction motor 102 and the traction inverter 104 to protect the traction inverter 104. During the operation of the traction motor 102, the control unit 106 continuously monitors the voltage levels, particularly the back emf generated in regenerative braking or high-speed conditions. When the control unit 106 detects that the back emf exceeds a predefined safety threshold, the control unit 106 sends a control signal to open the pair of switches 112. The operation of the pair of switches 112 breaks the electrical connection between the traction motor 102 and the traction inverter 104, thereby protecting the traction inverter 104 from potential overvoltage conditions. Beneficially, the implementation of the pair of switches 112 in the protection module 108 ensures the effective and rapid response to fluctuating back emf levels, thereby enhancing the safety, durability, and reliability of the powertrain unit 100.
In an embodiment, the control unit 106 is configured to close the pair of switches 112 of the protection module 108 when the detected back emf is under the predefined safety threshold. During the operation of the traction motor 102, the control unit 106 detects the back emf generated and compares the back emf against the predefined safety threshold. When the detected back emf is within the predefined safety threshold, the control unit 106 may be configured to close the pair of switches 112 present in the protection module 108. The closing of the pair of switches 112 facilitates the electrical connectivity between the traction motor 102 and the traction inverter 104, enabling normal power transmission for the operation of the traction motor 102. Beneficially, the controlling of the pair of switches 112 ensures that the traction inverter 104 remains protected while allowing efficient power flow when back emf is within safe operating limits. Additionally, the automatic operation of the protection module 108 by the control unit 106 enhances the reliability of the powertrain unit 100 and prevents unnecessary disconnection of the traction motor 102, thereby maintaining optimal vehicle performance.
In an embodiment, each of the switch is a bidirectional-controlled switch. The bidirectional-controlled switches are connected with the phases of the traction motor 102 and are operable to regulate energy flow between the traction motor 102 and the traction inverter 104. The bidirectional nature of the pair of switches 112 allows for controlled conduction and blocking of current in both directions, ensuring efficient handling of regenerative braking energy and suppressing excessive back emf. The bidirectional-controlled switch may be a Back-to-Back MOSFETs, an IGBT-Based Bidirectional Switches, TRIAC (Triode for Alternating Current) etc.
In an embodiment, the powertrain unit 100 of the electric vehicle. The powertrain unit 100 comprises the traction motor 102, the traction inverter 104, electrically connected to the traction motor 102 and the control unit 106 communicably coupled with the traction motor 102 and the traction inverter 104. The traction motor 102 comprises the protection module 108 to protect the traction inverter 104 during back emf generation by the traction motor 102. Furthermore, the powertrain unit 100 comprises the power pack 108. Furthermore, the traction motor 102 comprises the star point 110, wherein the protection module 108 is integrated with the star point 110 of the traction motor 102. Furthermore, the control unit 106 is communicably coupled with the protection module 108 to control the operation of the protection module 108. Furthermore, the protection module 108 comprises the pair of switches 112, wherein each switch of the pair of the pair of switches 112 is connected with the phase of the traction motor 102. Furthermore, the control unit 106 is configured to detect the back emf generation by the traction motor 102 and configured to determine whether the detected back emf exceeds the predefined safety threshold. Furthermore, the opening of the pair of switches 112 breaks electrical connection between the traction motor 102 and the traction inverter 104 to protect the traction inverter 104. Furthermore, the control unit 106 is configured to close the pair of switches 112 of the protection module 108 when the detected back emf is under the predefined safety threshold. Furthermore, each of the switch is a bidirectional-controlled switch.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combination of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non- exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:WE CLAIM:
1. A powertrain unit (100) of an electric vehicle, wherein the powertrain unit (100) comprises:
- a traction motor (102);
- a traction inverter (104), electrically connected to the traction motor (102); and
- a control unit (106) communicably coupled with the traction motor (102) and the traction inverter (104),
wherein the traction motor (102) comprises a protection module (108) to protect the traction inverter (104) during back emf generation by the traction motor (102).
2. The powertrain unit (100) as claimed in claim 1, wherein the powertrain unit (100) comprises a power pack (108).
3. The powertrain unit (100) as claimed in claim 1, wherein the traction motor (102) comprises a star point (110), wherein the protection module (108) is integrated with the star point (110) of the traction motor (102).
4. The powertrain unit (100) as claimed in claim 1, wherein the control unit (106) is communicably coupled with the protection module (108) to control the operation of the protection module (108).
5. The powertrain unit (100) as claimed in claim 1, wherein the protection module (108) comprises a pair of switches (112), wherein each switch of the pair of switches (112) is connected with a phase of the traction motor (102).
6. The powertrain unit (100) as claimed in claim 1, wherein the control unit (106) is configured to detect the back emf generation by the traction motor (102) and configured to determine whether the detected back emf exceeds a predefined safety threshold.
7. The powertrain unit (100) as claimed in claim 6, wherein the control unit (106) is configured to open the pair of switches (112) of the protection module (108) when the detected back emf exceeds the predefined safety threshold.
8. The powertrain unit (100) as claimed in claim 7, wherein the opening of the pair of switches (112) breaks electrical connection between the traction motor (102) and the traction inverter (104) to protect the traction inverter (104).
9. The powertrain unit (100) as claimed in claim 6, wherein the control unit (106) is configured to close the pair of switches (112) of the protection module (108) when the detected back emf is under the predefined safety threshold.
10. The powertrain unit (100) as claimed in claim 5, wherein each of the switch is a bidirectional-controlled switch.