Torque Ripple Reduction Research Articles

Advances in BLDC motor control: A thorough examination of torque ripple reduction and speed regulation techniques

Applications that depend on variable speed drives have one main concern: accurate and efficient control of Brushless Direct Current (BLDC) motors. This research explores the key factors that determine the performance of BLDC motors, including torque, motor speed and flux or electromagnetic back-emf fluctuation for optimal efficiency. Although optimal circumstances need continuous torque generation in BLDC motors with trapezoidal back emf, real-world situations result in pulsing torque because of elements such as changes in the motor's manufacturing structure and design, such as slot and teeth. Because of their efficiency, dependability and precise control capabilities, BLDC motors have acquired appeal across a wide range of applications. They are inherently prone to torque ripple and need sophisticated speed management for maximum performance. Torque ripple in BLDC motors is caused by the interaction of the rotor's permanent magnets with the stator's ferromagnetic teeth, which varies in strength throughout the magnetic field and causes unpredictable torque variations. This torque ripple can have a negative impact on speed-torque characteristics, causing noise, vibrations and probable problems in sensorless drives. This study provides a thorough examination of several approaches for decreasing torque ripple. The analysis demonstrates that torque ripple in BLDC motors can be reduced by boosting the input voltage during commutation, magnifying it fourfold compared to the back emf. In addition, the research examines alternative approaches for increasing input voltages throughout the commutation time. These discoveries contribute to the progress of BLDC motor control approaches, allowing for smoother operation and greater performance in a variety of applications.

A Novel Asymmetric Interior Permanent Magnet Machine with Auxiliary Flux Barriers

AbstractA novel asymmetric interior permanent magnet (AIPM) machine is proposed in this paper. The machine's rotor consists of asymmetric poles and auxiliary flux barriers. The torque ripple of the machine is weakened by the asymmetric design of the left and right sides of the magnetic poles. The magnetic‐field‐shifting (MFS) effect improves the electromagnetic torque after adding the auxiliary flux barrier to shift the magnetic axis. The influence of critical geometrical parameters on the electromagnetic performance of the machine is investigated under the condition that the stator and permanent magnet volume remain unchanged. The relevant geometrical parameters of the machine are optimized and designed through the improved Taguchi method. The performance of the AIPM machine and the conventional machine under no‐load and load conditions are further compared by simulation analysis with finite elements, verifying the increase in electromagnetic torque and the reduction in torque ripple. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Torque Ripple Reduction in Brushless Wound Rotor Vernier Machine Using Third-Harmonic Multi-Layer Winding

This article aims to realize the brushless operation of a wound rotor vernier machine (WRVM) by a third-harmonic field produced through stator auxiliary winding (X). In the conventional model, a third-harmonic current is generated by connecting a 4-pole armature and 12-pole excitation windings serially with a three-phase diode rectifier to develop a pulsating field in the airgap of a machine. However, in the proposed model, the ABC winding is supplied by a three-phase current source inverter, whereas the auxiliary winding (X) carries no current due to an open circuit. The fundamental MMF component developed in the machine airgap creates a four-pole stator field, while the third-harmonic MMF induces the harmonic current in the specialized rotor harmonic winding. The rotor on the other side contains the harmonic and the field windings connected through a full-bridge rectifier. The electromagnetic interaction of the stator and rotor fields generates torque. Due to the open-circuited winding pattern, the proposed machine results in a low torque ripple. A 2D model is designed using JMAG-Designer, and 2D field element analysis (FEA) is carried out to determine the output torque and machine’s efficiency. A comparative performance analysis of both the conventional and proposed topologies is discussed graphically. The quantitative analysis of the proposed topology shows better performance as compared to the recently developed third-harmonic-based brushless WRVM topology in terms of output torque and torque ripples.

Non-Weighted Two-Stage Model Predictive Control Strategy Based on Three-Level NPC Inverter

This paper investigates the asynchronous motors driven by a Three-Level Neutral-Point-Clamped Voltage Source Inverter (3L-NPC-VSI) and aims to achieve control without weight factors and reduce torque ripple. It puts forward a non-weighted two-stage Finite-Control-Set Model Predictive Control (FCS-MPC) strategy. First, a hierarchical optimization method is adopted to address the difficulty of setting weight factors in traditional FCS-MPC applications. The method offers stratified designs of three performance indices, voltage jump, common-mode voltage, and current tracking, obviating the need for weight factor setting and reducing the calculation load of predictions. Secondly, to further mitigate torque ripple, an optimal vector or vector combination is implemented at the current control layer by adhering to the principle of minimal current tracking error. During the selection of the optimal vector combination, the first vector of the combination is chosen to be the vector at the end of the present cycle. This ensures that there is at most one switch within each control period, reducing the switching losses of the two-stage FCS-MPC. Lastly, detailed simulation and experimental analyses are conducted to verify the feasibility and effectiveness of the proposed strategy.

Comparative assessment of a novel 8/18 multi-teeth with conventional 8/10 in-wheel SRM for an E-Scooter

Electric scooters are increasingly gaining popularity in India owing to rising global crude oil prices and rising levels of vehicular pollution. Most of them are currently powered by expensive in-wheel (IW) permanent magnet (PM) brushless DC motors. Owing to their simplicity, and ruggedness while being cost-effective (since they do not employ PMs), switched reluctance motors (SRMs) are a viable alternative. Despite these benefits, SRMs possess drawbacks such as low torque density and inferior efficiency. Recently, a multi-teeth (MT) SRM with an improved performance was reported. However, the design of MTSRM topologies and their electromagnetic performance have not been explored sufficiently. In this paper, a design formula governing the selection of the number of MT and rotor poles for MTSRMs has been proposed. Using this, a novel four-phase 8/18 IW-MTSRM is derived and proposed for an E-scooter. The characteristics of the proposed SRM are numerically compared with a conventional 8/10 SRM based on magnetic characteristics, efficiencies and steady-state operation for the complete torque-speed range. Results indicate that the proposed 8/18 MTSRM has a higher peak torque capacity, torque density, superior drive cycle efficiency and reduced torque ripple. Further, the FEA model is validated experimentally on a downsized 8/18 MTSRM prototype.

Sustainable power management in light electric vehicles with hybrid energy storage and machine learning control

This paper presents a cutting-edge Sustainable Power Management System for Light Electric Vehicles (LEVs) using a Hybrid Energy Storage Solution (HESS) integrated with Machine Learning (ML)-enhanced control. The system's central feature is its ability to harness renewable energy sources, such as Photovoltaic (PV) panels and supercapacitors, which overcome traditional battery-dependent constraints. The proposed control algorithm orchestrates power sharing among the battery, supercapacitor, and PV sources, optimizing the utilization of available renewable energy and ensuring stringent voltage regulation of the DC bus. Notably, the ML-based control ensures precise torque and speed regulation, resulting in significantly reduced torque ripple and transient response times. In practical terms, the system maintains the DC bus voltage within a mere 2.7% deviation from the nominal value under various operating conditions, a substantial improvement over existing systems. Furthermore, the supercapacitor excels at managing rapid variations in load power, while the battery adjusts smoothly to meet the demands. Simulation results confirm the system's robust performance. The HESS effectively maintains voltage stability, even under the most challenging conditions. Additionally, its torque response is exceptionally robust, with negligible steady-state torque ripple and fast transient response times. The system also handles speed reversal commands efficiently, a vital feature for real-world applications. By showcasing these capabilities, the paper lays the groundwork for a more sustainable and efficient future for LEVs, suggesting pathways for scalable and advanced electric mobility solutions.

Modified switching control of SRM drives for electric vehicles application with torque ripple reduction

The switched reluctance motor (SRM) offers extensive prospects, particularly within the realm of electric vehicles (EVs). Its robust construction, wide speed range, high torque density, and efficiency provide significant advantages that surpass other motors. Nonetheless, controlling these motors is more intricate when compared to conventional DC brushed or AC motors. This complexity arises due to the non-linear inductance characteristics of SRMs, resulting in undesirable effects like torque ripple, vibrations, and noise. Using the conventional full-bridge inverter, three switching approaches are highlighted for various operating modes of an EV. This aims to reduce costs and the number of switching pulses, leading to a more compact system, elimination of dead time, and switching losses. The MATLAB/Simulink platform was utilized to examine the operational effectiveness of a three-phase 6/4 poles SRM drive. Additionally, this paper focuses on mitigating torque ripple concerns by employing an adaptive neuro-fuzzy inference system (ANFIS) controller that has better efficiency and superior responses compared to conventional controllers such as fuzzy logic control (FLC) and proportional integral (PI) control. The results of the simulation encourage the practical implementation of the system, which is the next step in the author’s research.

Windage Loss and Torque Ripple Reduction in Stator-Permanent Magnet Flux-Switching Machines Using Quasi-Cylindrical Function Contour Rotor

Windage Loss and Torque Ripple Reduction in Stator-Permanent Magnet Flux-Switching Machines Using Quasi-Cylindrical Function Contour Rotor

Fuzzy Logic Control of Asynchronous Machine Drives With a Fractional Calculus Technique

—This paper proposes the use of fractional-order fuzzy logic (FOFL) to control the rotational speed of asynchronous machines (AMs) using the pulse width modulation and compares the results with field-oriented command (FOC). The contributions of this paper are to use FOFL instead of proportional-integral (PI) controller to control torque and flux and prove that it can reduce torque ripple and increase durability of control system. This work reveals that this strategy is very suitable to efficiently control systems without knowing their mathematical model, as is the case with FOC. The FOFL is tested with numerical simulations conducted in Matlab software under the different tests, where the obtained results are compared with FOC. The simulation results showed that the FOFL provided a clearly better performance in decreasing the torque, current, and flux ripples, where, compared to the FOC, the ripple reduction ratio was estimated at 44.44%, 51.72%, and 80.95% for torque, current, and flux, respectively. In addition, the FOFL reduces the time responses for changes in the speed, flux, and torque, where, compared to FOC, the FOFL minimized the time response by rates estimated at 4.47%, 94.77%, and 89.44% for each of the speed, flux, and torque, respectively.

MPC Based Position Sensorless SRM Drive for Light Electric Vehicles With Optimized Voltage Vectors and Reduced Torque Ripple

MPC Based Position Sensorless SRM Drive for Light Electric Vehicles With Optimized Voltage Vectors and Reduced Torque Ripple

Advanced Torque Sharing Function Strategy With Sliding Mode Control for Switched Reluctance Motors

In this paper, an improved torque sharing function control (TSF) using sliding mode control (SMC) is proposed for switched reluctance motor (SRM). First, as for TSF control strategy, due to low increase rate of inductance in the commutation interval, the latter phase is compensated with torque error for torque ripple reduction. Second, SMC is applied in design of speed controller and disturbance observer for better comprehensive performance. Regarding speed controller, the novel sliding mode reaching law is proposed to further suppress the torque ripple and accelerate approaching speed. With respect to the disturbance observer, a modified super-twisting algorithm is employed to enhance the anti-interference ability. Finally, the simulation and experiments are carried out, which verify that the proposed control method behaves better in aspects of the dynamic response and torque ripple suppression, and anti-interference ability.

Trade-off between torque ripple and vibration in an IPMSM by examining the temporal and spatial harmonics of flux density

Despite continuous effort to minimize torque ripple, the reduction of vibration has not been yet achieved due to the lack of link between these two performances. The difficulty of investigating the relationship stems from the fact that torque is solely influenced by tangential force whereas vibration is directly tied to radial force. In this paper, the correlation between torque ripple and vibration in an IPMSM (Interior Permanent Magnet Synchronous Motor) is established by examining the air-gap flux density in both radial and tangential directions. Its temporal and spatial harmonics are analyzed. A six-pole nine-slot IPMSM is used as a base configuration, and the air-gap flux density is varied by changing the height of a stator tooth tip. In the previous study, the same approach has been done to observe how to reduce torque ripple effectively. In this study, however, it is found that the trend of torque ripple is not the same as that of vibration with respect to the height of a pole tip, and the relation between the two is thoroughly observed and explained.

A novel auxetic stator winding to improve the performance of permanent magnet synchronous electric motors

High efficiency and torque density in permanent magnet synchronous motors (PMSMs) have contributed to their increasing popularity. Nonetheless, these advantages are compromised by higher vibration levels resulting from the torque ripple issue and magnetic flux density in the stator, causing magnetic forces on the stator surface. In this study, a new smart shape for the stator winding is proposed which reduces unwanted torque vibration and the overall magnetic flux density while keeping the same motor efficiency. The proposed windings shape is designed based on the auxetic principle and a locally resonant mechanism (LRM). Afterward, the proposed and original PMSM models are compared by looking at the average torque, total losses, torque ripple, flux density, output power, and motor efficiency under different speed operating conditions. In addition, the sensitivity analyses of the proposed model reveal the influence of auxetic structural parameters and initial mechanical angle on the system’s performance, which can be utilized to control the physical and mechanical properties of the system. According to the results, the designed model reduces torque ripple and magnetic flux density in the stator region by 41.38% and 4.70%, respectively, while the motor efficiency remains unaffected. The present work offers a potentially robust and affordable solution for regulating the vibration behavior of electric motors without impacting power efficiency.

A Review on the Fault-Tolerant Method of PMSM using Finite Element Method by Modifying Phase Angle for EV Applications

Abstract: The present research reviews a fault-tolerant technique for Permanent Magnet Synchronous Motors (PMSMs) that involves phase angle adjustment. Fault tolerance standards for the motor used in electric vehicles are necessary due to the rapid development of these vehicles. The primary option for electric vehicle drive motors is increasingly being replaced with permanent magnet synchronous motors (PMSM), which have minimal torque ripple, great durability, and other benefits. After comparing a six-phase PMSM to a conventional three-phase PMSM, the performance following a phase open is examined. A fault-tolerant technique for modifying the left phase current's phase angle to reduce torque ripple following a phase open is then described. The finite element simulation indicates that the six-phase PMSM's output torque ripple is reduced, and the fault-tolerant technique that is being described can further reduce the torque ripple.

An enhanced predictive current control technique for interior permanent magnet synchronous motor drives with extended voltage space vectors for electric vehicles

SummaryPermanent magnet synchronous motors (PMSM) are widely employed in the application of electric vehicles (EVs) due to their simplicity of operation. Model predictive current control (MPCC) is an advanced technique used to control the PMSM owing advantages like multi‐variable cost function and good dynamic performance. Cost function of predictive current control (PCC) does not require the flux weighting factor; hence, it is simple in the selection of suitable voltage vector (VV). The conventional PCC (C‐PCC) applied to interior PMSM (IPMSM) contains more torque and flux ripples as it includes only one set of voltage vectors for all speed ranges. In proposed PCC (P‐PCC), the magnitude and location of voltage vectors is to be selected as large and small VVs to reduce torque ripples. The P‐PCC in this article utilizes two set of extended voltage vectors (large and small VVs) based on the applied speed change in dynamic conditions and hence reduces the ripple content. Incorporating maximum torque per ampere (MTPA) control in this article serves the purpose of optimizing the machine performance. By adding MTPA to the proposed method, it is aimed to enhance the machine performance with less ripples and improved torque response. Simulation results are presented for conventional and P‐PCC to highlight the effectiveness and efficacy of the P‐PCC. The P‐PCC is experimentally verified with 3.7 kW PMSM using d‐SPACE controller.

Prior Computation of the Stator Current Dynamic Response for Torque Ripple Reduction in AC Motor Drives

In electric vehicles, the performance of the electric motor drive system depends on the characteristics of the control scheme applied. This paper discusses the torque ripple in an induction motor drive scheme exclusively and also proposes a new scheme to minimize it. The major cause of the torque ripple in induction motor drive is the presence of a high stator torque component (q-axis current) ripple. In the proposed scheme, the inverter is switched with the optimal duty ratio for the minimum q-axis current ripple. This leads to a decrease in q-axis current error and eventually torque ripple reduction. The distortion of the stator current waveform is also limited and gives rise to lower total harmonic distortion (THD). The feasibility of this proposed duty ratio modulated (DRM) improved torque and flux control scheme is studied using the MATLAB/Simulink computation tool and validated through appropriate experimentation.

Winding-MMF-based design and investigation of dual-winding hybrid-tooth vernier permanent magnet motor with reduced torque ripple and improved power factor

In this paper, in order to further reduce torque ripple and improve power factor, a new vernier permanent magnet motor is proposed, in which the design concept of dual-winding hybrid-tooth configuration is incorporated. In order to clarify motor torque ripple and power factor, the winding-magnetomotive-force-based design and analysis method is proposed, in which harmonic characteristics are considered as key factors during the magnetic field modulation process. The relationship between harmonics generated by winding MMF, torque ripple, and power factor are investigated. In addition, the split-tooth vernier permanent magnet motor is also investigated as a referenced motor. Detailed comparisons between the DWHT-VPM motor and ST-VPM motor are carried out, including air gap magnetic field, torque, and power factor. Both theoretical and simulation results verify the reasonability of the proposed DWHT-VPM motor, and the effectiveness of the proposed winding-MMF-based analysis method, which provide a new potential research path for the design and analysis of flux modulation motors.

Analytical Torque Ripple Reduction Strategy for Flux Modulated Doubly-Salient Reluctance Motor Drives Based on ZSC Harmonic Regulation

Compared to the conventional doubly-salient reluctance motor (DRM) drives, the novel flux modulated DRM (FMDRM) drives can achieve a better overall torque performance due to the dc-biased sinusoidal current excitation. However, previous investigations only focus on the dc-biased and fundamental current components, and the contributions of current harmonics to the torque production are not clear. This paper proposes an analytical torque ripple reduction strategy for open-winding FMDRM drives based on zero-sequence current (ZSC) harmonic regulation. Firstly, the contribution of third-order ZSC harmonic to the electromagnetic torque is investigated together with the dc-biased sinusoidal current components. Secondly, an alternative torque component cancellation method is put forward, where the additional third-order ZSC is utilized to counteract the dominating part of the alternative torque generated by the dc-biased sinusoidal current for torque ripple reduction. Both the amplitude and initial phase angle of the additional third-order ZSC are calculated by the analytical equation of electromagnetic torque. Moreover, the corresponding three-dimensional current distribution is investigated to achieve the desired ZSC regulation. With the proposed scheme, the torque ripple can be effectively suppressed while maintaining high output torque capability and efficiency. Furthermore, experimental results are presented on a three-phase FMDRM prototype to verify the proposed strategy. <fn fn-type="other" id="fn3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> </fn>

A Novel Harmonic Current Control Method for Torque Ripple Reduction of SPMSM Considering DC-Link Voltage Limit

A Novel Harmonic Current Control Method for Torque Ripple Reduction of SPMSM Considering DC-Link Voltage Limit

Investigation on ANFIS-GA controller for speed control of a BLDC fed hybrid source electric vehicle

The BLDC (Brushless DC Motor) is utilized in electric vehicles, space missions, and mechanical applications. Neural Network Inference System reduces torque ripple for hybrid electric vehicle (PV-Battery) along with BLDC drive to achieve efficient speed performance and stability. A hybrid input source methodology is thus put forwarded to drive the stator currents giving exactly the expressed electromagnetic torque and counter-EMF harmonics. The torque and speed control technique are directed to neural network interference system, and H6 Voltage Source Inverter (H6 VSI) drives BLDC with a gate pulse signal. We examine how an ANFIS-GA torque controller may eliminate BLDC torque ripples under uninterrupted hybrid power supply in this work. MATLAB (Simulink) results show that Genetic Algorithm (GA) improves training of ANFIS better with varying set speed conditions. The ANFIS-GA controller outperforms challenging controllers under various BLDC motor driving load conditions, proving its efficiency.