Torque Ripple Minimization Research Articles

Torque Ripple Minimization and Radial Force Reduction for Switched Reluctance Motor Drive Using Offline Gaussian Torque Sharing Function

Torque Ripple Minimization and Radial Force Reduction for Switched Reluctance Motor Drive Using Offline Gaussian Torque Sharing Function

A Novel Universal Torque Control of Switched Reluctance Motors for Electric Vehicles

Due to their advantages, switched reluctance motors (SRMs) are interesting solutions for electric vehicle (EV) propulsion. However, they have the main drawback of high torque ripple. This paper develops a universal torque control (UTC) technique for SRM that can fulfill all vehicle requirements under a wide range of speeds. The developed UTC involves two different control techniques. It utilizes the direct instantaneous torque control (DITC) strategy in a low speed region, and the average torque control (ATC) strategy in high speeds. The selection of DITC and ATC is made based on their performance regarding torque ripple, torque/current ratio, and efficiency. Moreover, a novel transition control between the two control techniques is introduced. The results show the ability of the proposed UTC to achieve vehicle requirements while obtaining all the benefits of torque control over the possible range of speeds. The proposed UTC provides the best performance regarding minimum torque ripple, maximum torque/current ratio, and maximum efficiency over the whole speed range. The transition control achieves a smooth operation without any disturbances. The transition control helps to simplify the overall control algorithm, aiming to have a feasible and practical UTC without a complicated control structure.

Investigation on torque ripple minimization in switched reluctance motor by using different techniques associated with TSF taking into account of magnetic saturation effects

In this work, three control techniques of minimization of torque ripple in SRM are proposed and compared to the classical control technic names as Hysteresis control proposed in [1]. The principle of these methods is based on the Torque Sharing Function (TSF) fixing the reference torque in each phase. In the literature review, the classical method used in the reduction of torque ripples in SRM is the TSF-Hysteresis Controller (TSF-H). The first proposed method is the TSF-Predictive control (TSF-P), here the objective is to find the voltage to be applied to the machine minimizing the error of the current through a prediction algorithm on the supply current. The second proposed method is the sliding mode control (TSF-SMC-PSO) whose parameters are optimized by the particle swarm algorithm (PSO). Finally, the third proposed method is the sliding mode controller whose parameters are optimized by fuzzy logic controller (TSF-SMFC). The finite element method (FEM) through the magnetic field calculation software FEMM was used to calculate the flux and torque in static system and to take into account magnetic saturation circuit of the SRM. The results obtained show that the TSF-SMC-PSO control methods have better performance compared to the other proposed methods mentioned above.

Minimization of torque ripples in PMSM drive using PI- resonant controller-based model predictive control

Minimization of torque ripples in PMSM drive using PI- resonant controller-based model predictive control

Instantaneous Torque Modeling and Torque Ripple Reduction Strategy for Flux Modulated Doubly-Salient Reluctance Motor Drives

In this article, a novel instantaneous electromagnetic torque modeling technique and current component distribution strategy are proposed for torque ripple reduction in three-phase flux modulated doubly-salient reluctance motor (FMDRM) drives. First, the analytical model of the instantaneous electromagnetic torque of a three-phase FMDRM is established, where the contributions of current components and harmonic inductance components are considered. The generation mechanisms of the average torque and torque ripple components are investigated in detail. Furthermore, based on the analytical instantaneous electromagnetic torque model, a simplified current component distribution strategy is proposed to further reduce the torque ripple of the FMDRM. Taking the torque ripple minimization as the optimization objective, the current advanced angle is optimized and the corresponding current component distribution strategy is carried out to reduce the torque ripple. The magnetic circuit saturation effect is also taken into account. Compared to the conventional scheme, the control freedom degree of the three-dimensional current controller in the FMDRM drive is fully utilized and the torque ripple of the FMDRM can be significantly reduced without the sacrifice of output torque capability and system efficiency. Experimental results are carried out on a three-phase 12/8 FMDRM prototype to verify the effectiveness of the proposed control strategy.

PMSM Torque Ripple Minimization Based on Novel Low Carrier Ratio PWM Technique

Harmonic injection is commonly used in permanent magnet synchronous motor torque ripple minimization (TRM) of electric vehicle. Traditional inverter switching frequency limits TRM application at high speed due to harmonic modulation accuracy and inverter loss. To achieve TRM in the whole speed range and reduce inverter loss, a novel online calculated low carrier ratio pulsewidth modulation (LCRPWM) is proposed in this article. The carrier ratio determining regular according to the injected harmonics is established first. The relationship between injected harmonics and LCRPWM switching angle is revealed and a set of nonlinear equations is established. Thus, the problem is transformed from solving nonlinear equations into optimization by establishing a cost function. The analytical solutions of nonlinear equations are obtained, which avoids iterative operation and plunging into local minimum. Therefore, the switch angle solution method is suitable for online calculation. The LCRPWM is verified in simulation compared with the traditional regularly sampled space vector PWM, which achieves better results in voltage harmonic injection and flux tracking at a much lower switching frequency. At last, the LCRPWM is used in a test bench experiment that shows good TRM effects. The influence of sideband harmonics on torque ripple is analyzed.

Four-Quadrant Model Following Sliding Mode Cruise Control for SRM With DITC Applied to Transportation Electrification

The ability of the four-quadrant operation is essential for transportation electrification applications. Switched reluctance machines (SRMs) have been increasingly considered an option for electric vehicles’ traction. However, achieving higher efficiency and low torque ripple may be a challenge for this type of machine, especially at low speeds. This article proposes a cruise control for SRM with the four-quadrant operation for extended autonomy. The cruise control is realized with a model following sliding mode speed controller and direct instantaneous torque control (DITC) for direct torque control. The proposed generating mode DITC aims for higher efficiency. An asymptotic stable model is developed for mode transition. The developed control system is Lyapunov stable in motoring, generating, and transition modes. Furthermore, an online multiobjective optimum point tracker (OPTPT) based on the steepest descent method is proposed aiming for efficiency maximization and torque ripple minimization. The experimental results show that the OPTPT convergence time is 1.25 s for a speed step and 1.2 s for a load step. The proposed control was submitted to an EUDC driving schedule, showing good speed regulation. The speed MAE of the cruise controller was 1.1344%. The transition between operation modes (motor–generator) occurs smoothly, which substantiates the proposed system for four-quadrant transportation electrification applications.

Investigation on Torque Sharing Function for Torque Ripple Minimization of Switched Reluctance Motor: A Flower Pollination Algorithm Based Approach

ABSTRACT Switched reluctance motor (SRM) drive has outstanding features like robust construction, double saliency, fault tolerance capability, and heat withstanding capability. Despite these, torque ripple is an intrinsic characteristic of SRM because of double salient geometry, air gap length, and switching sequence of motor phase currents, making it unsuitable for slick torque and high dynamic performances applications. This paper discusses the novel Torque Sharing Function (TSF) implementation and the flower pollination algorithm-based intelligent controller to minimize the torque ripples in Switched Reluctance Motor (SRM). TSF values depend on commutation angles during turn on, turn off, and overlapping angles. The proposed TSF and flower pollination algorithm evaluates the performance parameters using the machine model and controls the torque ripples for a wide range of speeds. Additionally, optimal results are obtained using three TSFs functions with valuable guidance provided for TSF selection. The proposed TSF with flower pollination algorithm-based intelligent controller finds its suitability for online evaluation of optimal turn on, turn off, and overlapping angles. The performance of the proposed method has effectively reduced the torque ripple in SRM than the Differential Evolution (DE) algorithm.

An Enhanced Fault-Tolerant Control of a Five-Phase Synchronous Reluctance Motor Fed From a Three-to-Five-Phase Matrix Converter

A five-phase fault-tolerant combined star-pentagon synchronous reluctance machine (SynRM) can provide a high torque density, minimal torque ripple, and superior fault tolerance. To enhance the performance of SynRM in the case of an open-circuit fault, this article proposes an optimal current angle to maximize the torque and minimize the torque ripple under the fault condition. The drive system consists of a five-phase combined star-pentagon SynRM fed from a three-to-five-phase matrix converter (MC). When determining the operating point of maximum torque per ampere (MTPA), the influence of fault and saturation on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$d$ </tex-math></inline-formula> - and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis inductances is considered. The healthy phases’ currents are reconstructed to guarantee a null value of zero-sequence current. Space vector modulation is applied to control the MC under the fault condition. Under the fault condition, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$z$ </tex-math></inline-formula> -subspace is properly controlled to reduce the overall harmonic distortions of current. Moreover, the performance of the drive system is analyzed using the finite element method (FEM) simulation and MATLAB program. Finally, the experimental tests validate the effectiveness of the suggested approach on a SynRM prototype drive system with a three-to-five-phase MC.

Minimization of torque ripples with optimized controller based four quadrant operation & control of BLDC motor

BLDC motors are widely utilized because of their qualities such as compact size, longer lifespan, and improved efficiency. In addition, BLDC motor available in a wide range of applications including aircraft, automation, computers, military, domestic appliances, and traction. These motors require an effective control method and also the controlling a BLDC motor in four quadrants are critical. Hence, An APID controller aimed at the speed regulation of the BLDC motor using multiple functions has been proposed in this paper. The curiosity of the proposed strategy is that it gives improved capacity, decreases improper irregular generation and can potential to change difficult optimization issues. Optimal benefit parameters are required to lessen torque ripples and regulate the speed of the BLDC motor by utilizing the APID controller. The hybrid method is the combination of the HHO and BWO based Luo converter. The proposed technique is straightforward in structure and heartiness to limit the issues of scientific figuring's. At the beginning, the optimization algorithms inspired by the nature of HHO and BWO are resolved to discover the problem in the work. Furthermore, the proficient hybrid HHO-BWO technique, which turns into the integrated strategy for the effective methodology, is executed to control the error values to provide the best optimal gain values. Here the control system, torque ripples have been diminished by regulating speed. EMF, stator current, torque, and speed are estimated based on the proposed regulation technique. The exhibition of the proposed system is implemented in the MATLAB/Simulink platform and compares with existing techniques such as HHO and BWO with APID control techniques.

Model Predictive Direct Torque Control and Fuzzy Logic Energy Management for Multi Power Source Electric Vehicles.

This paper proposes a novel Fuzzy-MPDTC control applied to a fuel cell battery electric vehicle whose traction is ensured using a permanent magnet synchronous motor (PMSM). On the traction side, model predictive direct torque control (MPDTC) is used to control PMSM torque, and guarantee minimum torque and current ripples while ensuring satisfactory speed tracking. On the sources side, an energy management strategy (EMS) based on fuzzy logic is proposed, it aims to distribute power over energy sources rationally and satisfy the load power demand. To assess these techniques, a driving cycle under different operating modes, namely cruising, acceleration, idling and regenerative braking is proposed. Real-time simulation is developed using the RT LAB platform and the obtained results match those obtained in numerical simulation using MATLAB/Simulink. The results show a good performance of the whole system, where the proposed MPDTC minimized the torque and flux ripples with 54.54% and 77%, respectively, compared to the conventional DTC and reduced the THD of the PMSM current with 53.37%. Furthermore, the proposed EMS based on fuzzy logic shows good performance and keeps the battery SOC within safe limits under the proposed speed profile and international NYCC driving cycle. These aforementioned results confirm the robustness and effectiveness of the proposed control techniques.

Mathematical Modelling and Torque Ripple Waning in BLDC Motor Using Outgoing-Phase Current Discharge Hysteresis Controlled ANFIS Controller

This study focused on approaches for reducing torque ripples in Permanent Magnet Brushless Direct current motors (PMBLDC) to provide sophisticated performance and reliable machine drives for both industrial and consumer applications. Torque ripples are caused by current ripple, nonsinusoidal Back Electromotive Force (EMF), and cogging torque at the Brushless Direct Current Motor (BLDCM) output. Acoustic emissions are produced when the torque ripple creates vibrations in the mechanical system, which interacts with the motor housing and reduces the life span of the motor. The BLDC’s uses are limited due to these acoustic emissions. Proportional-Integral (PI), Fuzzy Logic Control (FLC), and Adaptive Neuro-Fuzzy Inference System (ANFIS) speed controller approaches were used to construct and analyze the mathematical model of the BLDC motor in the MATLAB environment. The Adaptive Neurofuzzy Inference System (ANFIS) speed control system has solved the shortcomings of the PI and Fuzzy Logic Control (FLC) techniques. Because of FLC interpolation and flexibility, ANFIS is one of the finest trade-offs between neural and fuzzy systems, allowing for smooth control. Model compactness, a smaller training set, and faster convergence are all benefits of the ANFIS approach over traditional feedforward NN. In this research proposal, a simple control approach based on outgoing phase current discharge hysteresis control (OGCDHC) with minimal torque ripple is presented.

Comparative Study of BLDC Motor Drives with Different Approaches: FCS-Model Predictive Control and Hysteresis Current Control

The control techniques of the brushless DC (BLDC) motor have gained a large amount of interest in recent years, with their use being implemented in order to achieve a high-performance drive, including quick transient response and high-quality waveforms at the steady state. This paper provides a comparative study between three control schemes of BLDC motors: the direct power control scheme using a finite control set model predictive control (FCS-MPC) approach, the stator current controlled scheme using an FCS-MPC approach, and the stator current controlled scheme using ON–OFF hysteresis current controllers. The three systems were studied and investigated under the same operating conditions. The comparative study included investigating the performance of the BLDC drive in both steady state and transient operations. Qualitative and quantitative analyses were performed on the results obtained with each control scheme. The obtained results demonstrate the validity and effectiveness of the three investigated schemes in controlling the motor speed to the desired value under sudden load changes and achieving satisfactory quick transient responses. However, the results indicate the superiority of the direct power control scheme using an FCS-MPC approach over the others in terms of its minimum torque ripple, lowest torque and speed pulsations, minimum active and reactive power ripples, and high-quality waveforms of the stator currents drawn by the motor with minimum THD.

Investigation of Torque Ripple Behaviour for Five-Level Inverter-Fed Modified Model Predictive Torque Control-Based PMSM Drive

This paper investigates the minimization of torque ripple in Permanent Magnet Synchronous Motor (PMSM) Drive using the Modified Model Predictive Torque Control (MMPTC) with multilevel inverters. The MMPTC grabs the good steady-state performance as of Model Predictive Current Control (MPCC) and provides direct torque control as in the Model Predictive Torque Control (MPTC). The MMPTC strategy also eliminates weighting factors in the cost function, unlike conventional Model Predictive Torque and Flux control (MPTFC). The torque ripple causes vibrations and noise and produces more heat loss in the drive, which leads to focus on the torque ripple reduction. Among the various torque ripple minimization approaches, the multilevel inverter configuration clutched more attention in electric drives due to rapid development in the semiconductor technology. Analysis of torque ripple behaviour of PMSM drive with MMPTC using two-level (2L), three-level (3L), and five-level (5L) inverters is carried out under different running conditions in MATLAB/SIMULINK software tools and also implemented in real-time with the help of dSPACE1104 controller.

Brushless Wound Rotor Synchronous Machine Based on a Consequent-Pole Rotor Structure with Better Torque Attributes

This paper presents a subharmonic-based brushless wound rotor synchronous machine (BL-WRSM) topology with permanent magnet-assisted (PMA) and consequent-pole (CP) rotor structures to achieve better torque characteristics as compared to the conventional subharmonic-based brushless WRSM. The proposed topologies use the conventional high-efficient subharmonic field excitation technique to achieve a brushless operation and a lower volume of permanent magnet (PM) to achieve better average, starting, maximum, and minimum torques and lower torque ripple. A four-pole, twenty-four-slot (4-pole/24-slot) machine with conventional, PM-assisted (PMA), and consequent-pole (CP) rotor structures are developed in a JMAG-Designer 20.1 environment to carry out two-dimensional finite element analysis (2D-FEA). The developed machines are used to validate the operation and achieve electromagnetic and electromechanical performances of the proposed subharmonic-based BL-WRSM topologies with better torque attributes.

An enhanced control method for torque ripple minimization of switched reluctance motor using hybrid technique

In this manuscript, a hybrid technique is proposed for Torque Ripple (TR) minimization of Switched Reluctance Motor (SRM). The proposed technique is the consolidation of Wingsuit flying search (WFS) optimization and Gradient Boosting Decision Tree (GBDT) algorithm, hence it is known as WFS-GBDT technique. The control mechanisms consists of fractional order proportional integral derivative (FOPID) speed controller on external loop as well as current controller on internal loop with controlling turn activate and deactivate angles for SRM. The complexity of acquiring the ideal evaluation of proportional, integral and derivative gains for speed and current controller including turn activate and deactivate angles are deemed as a multi-objective optimization issue. Here, the WFS optimize the gain parameters of external speed loop along internal current loop with commutation angles for turn activate and deactivate switches. The WFS optimization processing is used to productive machine learning dataset under the types of SRM parameter. By using the satisfied dataset, the GBDT is predicted and mandatory forecasting is implemented in the entire machine operating stage. The optimized gain parameters based, the fractional order proportional integral derivative controller is tuned exactly. The proposed WFS-GBDT control technique lessens the torque ripple and quick settling time with this proper control, because of its systematic random search capabilities, thereby enhancing the dynamic execution of SRM drive. Finally, the proposed technique is activated in MATLAB/Simulink site, its performance is analyzed with existing techniques, like Base, ALO and WFS. The best, worst, mean, standard deviation for ISEspeed using proposed technique attains 230.5364, 231.5934, 230.952 and 0.05314. The best, worst, mean and standard deviation for torque ripple using proposed technique attains 0.4571, 0.6548, 0.585 and 0.472. The best, worst, mean, standard deviation for ISEcurrent using proposed technique attains 3.1257, 3.9754, 3.5783 and 0.0472.

Design and Optimization of a Magnetic-Geared Direct-Drive Machine With V-Shaped Permanent Magnets for Ship Propulsion

This article presents a novel magnetic-geared direct-drive machine (MGDM) with V-shaped permanent magnets (PMs) installed on its rotor. By extending the inner rotor shaft and connecting it to a prime motor, the torque and power density of the proposed MGDM are boosted. In addition, compared with the conventional MGDM with surface-mounted PMs (SPMs), the proposed MGDM with V-shaped PMs has a more robust rotor structure to cope with extreme operating conditions. The operating principle and structure requirement of this MGDM are first derived. Then, the geometrical parameters are optimized via a three-stage multiobjective optimization method to maximize output torque and efficiency and minimize torque ripple via the genetic algorithm (GA) and finite element analysis (FEA) combined optimization strategy. Furthermore, the proposed MGDM is artfully integrated into hybrid electric ships (HESs) to construct an onboard integrated power system (OB-IPS). Since the proposed system possesses various operating modes to cope with practical operating conditions, it enjoys a high systematic efficiency and good dynamic performance. Finally, a prototype is fabricated and tested with various operating modes by referring to the practical navigation cycle of an HES. The experimental results validate the feasibility of the proposed MGDM for being applied in HESs.

Speed control and torque ripple minimization of SRM using local unimodal sampling and spotted hyena algorithms based cascaded PID controller

This paper proposes the use of two recent optimization techniques, called the Local Unimodal Sampling (LUS) and the Spotted Hyena Optimizer (SHO), to optimally tune cascaded PID controller designed while controlling the speed and reducing the torque ripples of the switched reluctance motor. The proposed implementation of these algorithms has the advantage of better convergence and lower computational efforts when compared to other optimization techniques. To demonstrate the effectiveness of the proposed cascaded PID controller using LUS and SHO, they are compared to other controller designs present in previous literature, specifically the cascaded fractional-order PID (FOPID) controller. Results show that the PID controller is more superior to the FOPID controller and that the SHO-based cascaded PID controller leads to less current and torque ripples with better speed response. The study is implemented at different loading conditions. The results are presented in the form of a time-domain simulation conducted via MATLAB/SIMULINK.

Performance Comparison of Fault-Tolerant Control for Triple Redundant 3 × 3-Phase Motors Driven by Mono-Inverter

In this article, the fault-tolerant control (FTC) strategy based on current redistribution is compared for three types of triple redundant <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\times 3$ </tex-math></inline-formula> -phase motor: surface-mounted permanent magnet synchronous motor (SPMSM), synchronous reluctance motor (SynRM), and permanent magnet-assisted synchronous reluctance motor (PMa-SynRM), under a single-phase open-circuit fault. The output torque of SPMSM and SynRM is produced by permanent magnet (PM) torque and reluctance torque, respectively. Nevertheless, for PMa-SynRM, it is necessary to determine the distribution ratio of PM torque and reluctance torque in the proposed FTC strategy. By comparing the FTC performance of motors, the conclusions are as follows: 1) torque ripple of the SPMSM can be completely suppressed; 2) torque ripple minimization for the SynRM and PMa-SynRM can be realized; and 3) optimal solution obtained in SynRM can also be applied to the PMa-SynRM when the load is heavy. In addition, to reduce the complexity and improve the reliability of the control system, a mono-inverter-driven triple-paralleled control system is constructed in healthy and postfault operations. The comparison results of the FTC strategy for three types of motor are obtained by simulation. And the experimental results based on a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3\,\times \,3$ </tex-math></inline-formula> -phase PMa-SynRM are accomplished to verify the feasibility of the theory.

PMSM Current Harmonics Control Technique Based on Speed Adaptive Robust Control

Permanent magnet synchronous motor (PMSM) is widely used in electric vehicles due to its high power density. New requirements are constantly proposed with the development of PMSM, one of which is torque ripple. Current harmonic injection is a common method to minimize torque ripple. Designing effective controller to realize current harmonic injection is the key technology. In this paper, the transient voltage-current coupling equation considering magnetic saturation is derived by introducing incremental inductance. After appropriately simplifying, it is shown in form of the harmonic state space (HSS) equation. Considering that PMSM parameters varies with current due to magnetic saturation, robust controller is adopted to ensure stability. In order to eliminate the influence of motor speed change on control stability, the HSS is transformed into a spatial form. Then the speed adaptive robust (SAR) controller is designed. At last, the SAR controller is used in simulation and test bench experiment to verify dynamic response and stability. Compared with traditional PI and PR controller, the SAR controller can ensure good dynamic response, steady-state error and robust stability when speed and PMSM parameters vary. Moreover, SAR controller can well resist the harmonic coupling effect and system lag.