Description:ARRANGEMENT FOR DETERMINING ROTOR POSITION OF MOTOR
TECHNICAL FIELD
The present disclosure generally relates to a motor controls in electric vehicle. Particularly, the present disclosure relates to an arrangement for determining rotor position of a Permanent Magnet Synchronous Motor.
BACKGROUND
Recently, vehicles have become indispensable for personal transportation, commuting, and logistics which offer significant convenience by reducing travel time and providing flexibility. Additionally, electric and hybrid vehicles are gaining popularity due to environmental concerns and their fuel efficiency. Overall, electric vehicles play a crucial role in daily life, enhancing mobility and independence. Meanwhile, increasing usage of electric vehicles may also lead to an increase in demand for electric motors which are the heart of electric vehicles (EVs). The electric motors provide the fundamental driving force that propels electric vehicles.
Typically, the electric motors offer instant torque, delivering powerful acceleration from a standstill, which is one of the defining characteristics of EVs. This immediate response not only enhances driving performance but also contributes to a smoother and quieter ride. Also, for the better performance and efficiency of the motor and the vehicle, it is important to control the motor's performance precisely. Moreover, there is a need to manage two key things for improvement of electric motor performance which includes a flux (which is related to the magnetic field inside the motor) and a torque (which is the force that makes the motor turn).
Generally, in a typical AC motor, the flux (magnetic field) and the torque (rotational force) are inherently linked in the motor's stator (the stationary part of the motor), making it difficult to control them independently. Meanwhile, to address this challenge, motor drive systems commonly use Vector Control, also known as Field-Oriented Control (FOC) which allows the separate and precise control of both flux and torque of the motor. However, the accuracy in detection of rotor position of the motor rotor is mandatory to achieve independent closed-loop control of the flux and the torque. For these, the prior art generally uses an encoder installed on the motor to obtain the motor position information. In order to obtain the absolute position of the rotor of the motor, the most commonly used method is to use an absolute encoder. However, due to its complex internal structure and excessive cost, the application of absolute encoders is greatly restricted. Furthermore, as an alternative, the incremental encoder only outputs the number of pulses corresponding to the rotation of the motor, and has the advantages of simple internal structure, small size, and low cost. Moreover, a photoelectric encoder and a magnetic induction gear encoder are the two main forms of incremental encoders. However, the output signal of the incremental encoder may only reflect the incremental information of the position change of rotor of the motor. Furthermore, in order to realize the detection of absolute position information, a Z-pulse zero signal output by the incremental encoder is used to obtain the initial position. However, the Z-pulse position of the encoder is aligned with the rotor pole or a fixed angle deviation, then tighten the tightening screw of the encoder. These above requirements make the installation of the incremental encoder more difficult and time-consuming also labour-intensive. Furthermore, the data from received from the position encoder may have noise (interference) due to the electronic components such as traction inverter. Such noise may disturb the data. Moreover, a sensor less predictive analysis method in motor control involves estimating the future position of the motor's rotor based on current and past data, such as speed, angle, and electrical signals. By using mathematical models and algorithms, the system may anticipate the rotor's position in advance. This allows for real-time adjustments to the control inputs, ensuring precise synchronization between the rotor and the stator's magnetic field. However, the predictive analysis for detecting the rotor position has some of the imitations including sensitivity to model inaccuracies and noise in sensor data. Moreover, if the mathematical model used for prediction doesn't perfectly match the motor's real behaviour, errors may accumulate which leads to inaccurate predictions. Furthermore, the inaccuracies in position detection values of rotor may affects the accuracy of motor control.
Therefore, there exists a need for an improved mechanism of determining rotor position that overcomes the one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide an arrangement for determining rotor position of a Permanent Magnet Synchronous Motor.
In accordance with first aspect of the present disclosure, there is provided an arrangement for determining rotor position of a Permanent Magnet Synchronous Motor (PMSM). The arrangement comprises a traction inverter, a permanent magnet synchronous motor comprising a rotor, a motor control unit comprising a processing module, and a position sensor configured to determine change in position of rotor magnets with respect to the position sensor, to determine the rotor position.
The arrangement of the present disclosure is advantageous in terms of accurately determining rotor position of the motor. Furthermore, the arrangement of the present disclosure is advantageous in terms of removing noise from the sensor signal leading to accurate determination of the rotor position. The arrangement of the present disclosure offers significant advantages by improving the precision and control of rotor position information. The arrangement of the present disclosure is advantageous in terms of effectively reducing torque ripples and enhancing current control. The arrangement of the present disclosure ensures smoother operation and eliminates the risk of short circuits in the motor control. The arrangement of the present disclosure is enabling a more comfortable driving experience, increased efficiency, and extended component lifespan. Additionally, the arrangement of the present disclosure improves vehicle stability and safety by reducing the risk of unexpected breakdowns.
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 an arrangement for determining rotor position of a Permanent Magnet Synchronous Motor, 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 an arrangement for determining rotor position 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 terms ‘processing module’ and ‘processor’ are used interchangeably and refer to a computational element that is operable to respond to and processes instructions that drive the system. Optionally, the data processing arrangement 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 data processing arrangement 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 data processing arrangement 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 “electric motor” refers to primary component of the traction system that converts electrical energy into mechanical torque.
As used herein, the term “traction inverter” refers to a power electronic device that converts DC (direct current) power from a battery or other energy storage system into AC (alternating current) power to drive the electric motor in an electric vehicle. It plays a crucial role in controlling the speed, torque, and direction of the electric motor, enabling the vehicle to accelerate, decelerate, and change direction. The key functions of the traction inverter include voltage conversion, frequency control, torque control and regenerative braking.
As used herein, the term “rotor” refers to rotating component of the motor that generates mechanical torque by interacting with a rotating magnetic field generated by the stator assembly.
As used herein, the term “motor control unit” refers to electronic control unit that manages the operation of an electric motor. It receives input signals from various sensors and control systems and processes them to determine the appropriate control signals for the motor. The key functions of the motor control unit includes motor speed control, torque control, rotor position control, fault detection and protection, and communication with other electronic control units of the vehicle. The motor control unit may comprise a processing module to process various information received and generate control signal.
As used herein, the term “position sensor” refers to device that measures the angular position of a rotating shaft or rotor. The position sensor may include at least one of: a resolver type sensor, an encoder type sensor and/or a magnetic sensor.
Figure 1, in accordance with an embodiment describes an arrangement 100 for determining rotor position of a Permanent Magnet Synchronous Motor (PMSM). The arrangement 100 comprises a traction inverter 102, a permanent magnet synchronous motor 104 comprising a rotor 104a, a motor control unit 106 comprising a processing module 108, and a position sensor 110 configured to determine change in position of rotor magnets with respect to the position sensor, to determine the rotor position.
The arrangement 100 of the present disclosure is advantageous in terms of accurately determining rotor position of the motor. Furthermore, the arrangement 100 of the present disclosure is advantageous in terms of removing noise from the sensor signal leading to accurate determination of the rotor position. The arrangement 100 of the present disclosure offers significant advantages by improving the precision and control of rotor position information. The arrangement 100 of the present disclosure is advantageous in terms of effectively reducing torque ripples and enhancing current control. The arrangement 100 of the present disclosure ensures smoother operation and eliminates the risk of short circuits in the motor control. The arrangement 100 of the present disclosure is enabling a more comfortable driving experience, increased efficiency, and extended component lifespan. Additionally, the arrangement 100 of the present disclosure improves vehicle stability and safety by reducing the risk of unexpected breakdowns.
In an embodiment, the processing module 108 is configured to receive the change in position of the rotor magnets as primary change angle. Beneficially, the change in position of the rotor magnets allows for more precise and accurate control of the electric motor. By using the change in position of the rotor magnets as the primary reference, the processing module 108 can more effectively calculate and adjust the motor's speed, torque, and other parameters. This leads to smoother and more efficient operation of the electric motor.
In an embodiment, the processing module 108 is configured to process the primary change angle with an offset angle to determine a secondary change angle. Beneficially, the determination of the secondary change angle allows for greater flexibility and adaptability in controlling the electric motor. By introducing an offset angle, the processing module 108 can effectively compensate for any variations or inaccuracies in the primary change angle measurement. This may help to improve the accuracy and precision of the motor's control, even in challenging operating conditions.
In an embodiment, the processing module 108 is configured to process the secondary change angle with a first filter comprising a range of first threshold values and output a first tertiary change angle when the secondary change angle is within the range of first threshold values. Beneficially, the processing module 108 may effectively eliminate or reduce the impact of noise and other unwanted signals that may be present in the secondary change angle measurement. This can lead to a more accurate and reliable determination of the rotor’s position and other parameters, resulting in improved overall system performance. Additionally, the use of a first filter may help to prevent false triggering or erroneous control actions that may be caused by spurious signals. This may enhance the system's stability and reliability, especially in challenging operating environments.
In an embodiment, the processing module 108 is configured to process the first tertiary change angle with a second filter comprising a range of second threshold values and output a second tertiary change angle when the first tertiary change angle is within the range of second threshold values. Beneficially, the second threshold values are lesser than the first threshold values to further reduce noise in the signal.
In an embodiment, the processing module 108 is configured to process the second tertiary change angle with a third filter comprising a range of third threshold values and output a third tertiary change angle when the second tertiary change angle is within the range of third threshold values. Beneficially, the third threshold values are lesser than the second threshold values to further reduce noise in the signal.
In an embodiment, the processing module 108 is configured to process the third tertiary change angle with a fourth filter comprising a range of fourth threshold values and output a fourth tertiary change angle when the third tertiary change angle is within the range of fourth threshold values. Beneficially, the fourth threshold values are lesser than the third threshold values to further reduce noise in the signal.
In an embodiment, the processing module 108 is configured to process the fourth tertiary change angle with a fifth filter comprising a range of fifth threshold values and output a fifth tertiary change angle indicating the rotor position when the fourth tertiary change angle is within the range of fifth threshold values. Beneficially, the fifth threshold values are lesser than the fourth threshold values to further reduce noise in the signal.
In an embodiment, the processing module 108 is configured to bypass at least one of: the first filter, the second filter, the third filter, the fourth filter and the fifth filter when the output is not received from the particular filter. Beneficially, the processing module 108 does utilize previous value of the angle at the next step if the output is not received from the at least one of: the first filter, the second filter, the third filter, the fourth filter and the fifth filter due to respective value being outside the threshold range.
In an embodiment, the motor control unit 106 is configured to adjust motor performance based on the fifth tertiary change angle indicating the rotor position. Beneficially, the motor control unit 106 enables fine adjustments to the motor's speed, torque, and other parameters based on the exact position of the rotor.
In an embodiment, the arrangement 100 comprises the traction inverter 102, the permanent magnet synchronous motor 104 comprising the rotor 104a, the motor control unit 106 comprising the processing module 108, and the position sensor 110 configured to determine change in position of rotor magnets with respect to the position sensor, to determine the rotor position. Furthermore, the processing module 108 is configured to receive the change in position of the rotor magnets as primary change angle. Furthermore, the processing module 108 is configured to process the primary change angle with an offset angle to determine a secondary change angle. Furthermore, the processing module 108 is configured to process the secondary change angle with a first filter comprising a range of first threshold values and output a first tertiary change angle when the secondary change angle is within the range of first threshold values. Furthermore, the processing module 108 is configured to process the first tertiary change angle with a second filter comprising a range of second threshold values and output a second tertiary change angle when the first tertiary change angle is within the range of second threshold values. Furthermore, the processing module 108 is configured to process the second tertiary change angle with a third filter comprising a range of third threshold values and output a third tertiary change angle when the second tertiary change angle is within the range of third threshold values. Furthermore, the processing module 108 is configured to process the third tertiary change angle with a fourth filter comprising a range of fourth threshold values and output a fourth tertiary change angle when the third tertiary change angle is within the range of fourth threshold values. Furthermore, the processing module 108 is configured to process the fourth tertiary change angle with a fifth filter comprising a range of fifth threshold values and output a fifth tertiary change angle indicating the rotor position when the fourth tertiary change angle is within the range of fifth threshold values. Furthermore, the processing module 108 is configured to bypass at least one of: the first filter, the second filter, the third filter, the fourth filter and the fifth filter when the output is not received from the particular filter. Furthermore, the motor control unit 106 is configured to adjust motor performance based on the fifth tertiary change angle indicating the rotor position.
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. An arrangement (100) for determining rotor position of a Permanent Magnet Synchronous Motor (PMSM), the arrangement (100) comprises:
- a traction inverter (102);
- a permanent magnet synchronous motor (104) comprising a rotor (104a);
- a motor control unit (106) comprising a processing module (108); and
- a position sensor (110) configured to determine change in position of rotor magnets with respect to the position sensor, to determine the rotor position.
2. The arrangement (100) as claimed in claim 1, wherein the processing module (108) is configured to receive the change in position of the rotor magnets as primary change angle.
3. The arrangement (100) as claimed in claim 2, wherein the processing module (108) is configured to process the primary change angle with an offset angle to determine a secondary change angle.
4. The arrangement (100) as claimed in claim 3, wherein the processing module (108) is configured to process the secondary change angle with a first filter comprising a range of first threshold values and output a first tertiary change angle when the secondary change angle is within the range of first threshold values.
5. The arrangement (100) as claimed in claim 4, wherein the processing module (108) is configured to process the first tertiary change angle with a second filter comprising a range of second threshold values and output a second tertiary change angle when the first tertiary change angle is within the range of second threshold values.
6. The arrangement (100) as claimed in claim 5, wherein the processing module (108) is configured to process the second tertiary change angle with a third filter comprising a range of third threshold values and output a third tertiary change angle when the second tertiary change angle is within the range of third threshold values.
7. The arrangement (100) as claimed in claim 6, wherein the processing module (108) is configured to process the third tertiary change angle with a fourth filter comprising a range of fourth threshold values and output a fourth tertiary change angle when the third tertiary change angle is within the range of fourth threshold values.
8. The arrangement (100) as claimed in claim 7, wherein the processing module (108) is configured to process the fourth tertiary change angle with a fifth filter comprising a range of fifth threshold values and output a fifth tertiary change angle indicating the rotor position when the fourth tertiary change angle is within the range of fifth threshold values.
9. The arrangement (100) as claimed in claim 8, wherein processing module (108) is configured to bypass at least one of: the first filter, the second filter, the third filter, the fourth filter and the fifth filter when the output is not received from the particular filter.
10. The arrangement (100) as claimed in claim 8, wherein the motor control unit (106) is configured to adjust motor performance based on the fifth tertiary change angle indicating the rotor position.