Torque Ripple Reduction Research Articles

Performance Improvement of Axial Flux Permanent Magnet Machine with Phase Group Concentrated Coil Winding

This paper suggests a method to improve the performances of the Dual Stator Axial Flux Spoke-type Permanent Magnet (DSAFSPM) machines with phase group concentrated coil (PGCC) windings, by incorporating continuous and discrete step-skewing along with a special winding connection. The purpose of the study is to mitigate the cogging torque and torque ripples while increasing the output torque so it ameliorates the machine performance at minimum cost for various applications such as wind power plants and electric vehicles (EVs). Cogging torque produces noise and vibrations which degrade the machine’s performance and reduces its life span. The proposed winding sequence enhances the output torque by improving its distribution factor along with the use of continuous skew and step-skew magnets. This research work improved the cogging torque and torque ripples with the help of skew techniques while output torque is increased by the proposed winding sequence. Further harmonics and ripples are also mitigated by the proposed winding sequence. The overall machine volume is kept constant along with the magnet size and the design parameters for fair performance analysis. Comparative analysis of these machines is performed using three-dimensional (3-D) time-stepped finite element analysis (FEA). Proposed model I and proposed model II reduce the harmonics by 42% and 23%, respectively. By using continuous skew and discrete step-skew magnets, cogging torque is reduced up to 81.5% and 75%, respectively. This reduction in cogging torque reduces the noise and vibration in machines which assists the machines to perform a smooth operation. The reduction in output torque ripples in proposed model I is 60.8% while that of proposed model II is 59.3%.

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.

Back propagation neural network‐based torque ripple reduction strategy for high frequency square‐wave voltage injection‐based interior permanent magnet synchronous motor sensorless control

Back propagation neural network‐based torque ripple reduction strategy for high frequency square‐wave voltage injection‐based interior permanent magnet synchronous motor sensorless control

Control of Permanent Magnet Synchronous Motor Using MPC–MTPA Control for Deployment in Electric Tractor

This study aims to evaluate the interior permanent magnet synchronous motor (IPMSM) drive performance for various load conditions under steady state and dynamic conditions. Therefore, this paper proposes finite set model-predictive control (FS-MPC) for IPMSM with maximum torque per ampere (MTPA) for electric tractor application. The MTPA control technique is used to obtain maximum torque while maintaining a minimum current constraint. In addition to MTPA control, the MPC scheme is used as the suitable alternative control strategy in the electric tractor application, which eliminates the occurrence of torque ripples during the dynamic speed tracking under variable load conditions. The MPC is used to improve the dynamic response of the motor drive and reduce torque ripples under variable load conditions. MPC–MTPA is developed in the MATLAB/SIMULINK and validated in the real-time environment using the hardware-in-the-loop (HIL) simulator (OPAL-RT OP5700). The results prove that MPC improves the dynamic performance and MTPA reduces the stator copper loss and increases the drive efficiency.

An Improved Torque Ripple Reduction Controller for Smooth Operation of Induction Motor Drive

An Improved Torque Ripple Reduction Controller for Smooth Operation of Induction Motor Drive

ANFIS based Direct Torque Control of PMSM Motor for Speed and Torque Regulation

Nowadays, the Permanent Magnet Synchronous Motors (PMSM) are gaining popularity among electric motors due to their high efficiency, high-speed operation, ruggedness, and small size. PMSM motors comprise a trapezoidal electromotive force which is also called synchronous motors. Direct Torque Control (DTC) has been extensively applied in speed regulation systems due to its better dynamic behavior. The controller manages the amplitude of torque and stator flux directly using the direct axis current. To manage the motor speed, the torque error, flux error, and projected location of flux linkage are employed to adjust the inverter switching sequence via Space Vector Pulse Width Modulation (SVPWM). One of the most common problems encountered in a PMSM motor is Torque ripple, which is recreated by power electronic commutation and a better controller reduces the ripples to increase the drive's performance. Conventional controllers such as PI, PID and SVPWM-DTC were compared with the proposed Adaptive Neuro-Fuzzy Inference System (ANFIS) in terms of performance measures such as speed and torque ripple. In this work, the Two-Gaussian membership function of the ANFIS controller is used in conjunction with a PMSM motor to reduce torque ripple up to 0.53 Nm and maintain the speed with a distortion error of 2.33 %.

Synchronous Reluctance Motor Performance Improvement Using MTPA Control Strategy and Five-Level Inverter Topology

An improved vector control method is presented in this study to enhance synchronous reluctance motor (SynRM) performance. The maximum torque per ampere (MTPA) technique has demonstrated good dynamic properties since the torque control is closely tied to the current control. The selection of the control approach is primarily influenced by how the reference current values will be defined. Additionally, a five-level neutral-point-clamped (NPC) inverter replaces the traditional two-level inverter. Only eight voltage vectors can be produced by a two-level inverter, whereas one hundred twenty-five voltage vectors can be generated by a five-level inverter. The goal is to produce an output voltage vector that closely resembles the reference voltage vector in order to ensure a quick response on the one hand and enhance dynamic performance on the other. An exact comparison of the suggested vector control strategy's properties is made once it has been simulated in MATLAB/Simulink. The acquired findings are satisfactory and high performance is attained in terms of response time, torque ripple reduction, and current waveform improvement.

A Novel High-Voltage Gain Circuit Topology for Commutation Torque Ripple Reduction

The electronic commutation and the low inductance nature of the brushless dc motor (BLDC) deteriorate the expected performance. The ripples in the current waveshape are primarily due to the commutation of the phases, which is carried to produce a synchronously rotating magnetic field. This commutation ripples lead to mechanical pulsation and noise on the rotor side. This article presents a novel strategy for reducing the commutation torque ripple. The proposed topology uses a hybrid Ćuk voltage gain dc–dc converter at the front end, which has high voltage gain and which reduces voltage ratings of the dc supply. An auxiliary switch is connected across the dc link of the inverter to control the rate of rising incoming phase current during the phase change of the inverter with the help of the dc–dc converter. A prototype of a 1HP BLDC motor is used to validate the proposed topology both analytically and experimentally.

Remedy Strategy for Five-Phase FTPMMs Under Single-Phase Short-Circuit Fault by Injecting Harmonic Currents From Third Space

This article proposes a new fault-tolerant control for five-phase fault-tolerant permanent-magnet motors under single-phase short-circuit fault. In the proposed method, the effect on torque performance caused by a short-circuit fault is attributed into two parts: the loss of the short-circuited phase, which is equivalent to a phase open-circuit fault, and the resultant short-circuit current. The remedial action for loss of a phase is realized in the fundamental space, while the torque ripple caused by the short-circuit current is compensated by the harmonic currents in the third space. To decouple the control of the fundamental and third space, the reduced-order Clarke and Park transformation matrixes for the two spaces are obtained separately under single-phase short-circuit fault. Afterward, the fundamental currents with minimum joule losses or equal joule losses for loss of a phase, and the harmonic currents in the third space for torque ripple reduction are derived. Hence, the proposed method can realize torque ripple-free operation under single-phase short-circuit fault. Finally, the effectiveness of the proposed method is verified by experimental results under various operational conditions.

Research on Open-circuit Fault Tolerant Control of Six-phase Permanent Magnet Synchronous Machine Based on Fifth Harmonic Current Injection

This paper proposes a novel control approach for fault-tolerant control of dual three-phase permanent magnet synchronous motor (PMSM) under one-phase open-circuit fault. A modified six-phase static coordinate transformation matrix and an extended rotating coordinate transformation matrix are investigated considering the influence of the fifth harmonic space on fault-tolerant control. These mathematical models are further analyzed in the fundamental space and the fifth harmonic space after the fault and to eliminate the coupling between the d-q axis voltage equation in the fundamental wave space and the d-q axis voltage equation in the fifth harmonic space, a secondary rotation coordinate transformation matrix is proposed. To achieve the purpose of reducing torque ripple, the fault-tolerant control method proposed in this paper not only takes the minimum copper loss as the constraint condition, but also injects the fifth harmonic current. The experimental result of current and torque is used to verify the accuracy of fault-tolerant control.

Torque Ripple and Electromagnetic Vibration Suppression in Permanent Magnet Synchronous Motor Using Segmented Rotor With Different Pole Widths

In current engineering, the skewing slots approach is commonly used for permanent magnet synchronous motor (PMSM) to reduce torque ripple and electromagnetic vibration. However, this approach may limit the axial length of the motor and increase the manufacturing cost. This article studies a segmented rotor with different pole widths approach to mitigate torque ripple and electromagnetic vibration for PMSM, which has a lower implementation cost and facilitates mechanized production. The mapping relationship between geometric dimensions and torque performance is obtained, and the optimal dimensions are determined. An 8-pole/48-slot V-shaped PMSM is taken as the original motor, and the influence of engineering error on the torque performance of the presented approach is discussed. The electromagnetic performances and vibration responses of the motor with the presented approach are compared with that of the skewing slot motor to verify the effectiveness of the presented approach. Finally, prototypes are built, and intensive experimental tests are carried out to verify the analysis and comparison.

Multi-objective Predictive Control of 3L-NPC Inverter Fed Sensorless PMSM Drives for Electrical Car Applications

This paper proposes a multi-objective FS-MPC approach based on three-step optimization for a surface-mounted PMSM fed by a 3L-NPC inverter. It helps to significantly reduce torque ripples, current harmonics while controlling the inverter's neutral point voltage. To overcome the drawbacks of using mechanical sensors, a sliding mode observer is used to estimate the machine speed and rotor angular position. Compared to existing works, the proposed control method is implemented using the proportionality between the electromagnetic torque and the current component on the q-axis to eliminate the computational redundancy related to the current and torque control. To further reduce torque ripples and current harmonics, a 3L-NPC inverter is used. Compared to other types of three-level inverters, it uses less power semiconductors and attenuates the problem of voltage fluctuation at the neutral point and current harmonics. Matlab/Simulink simulations of the proposed approach yield a current THD of 1.69 %.

A torque ripple reduction method using field current injection for doubly salient motor

Doubly salient motor (DSM) is widely used owing to attractively in high-speed operation capability. However, there is a shortcoming of torque ripple for the non-sinusoidal nonlinear structure, for the purpose of solving this problem, this paper presents a torque ripple reduction strategy by field current injection for doubly salient motor. Initially, the armature current control method of the DSM adopts the multi-sine superposition (MSWS) driving scheme, combined with finite element and Fourier analysis methods to establish the output torque and torque ripple model, where the torque of the DSM is mainly composed of the 1st, 2nd, and 4th harmonic component, and the torque ripple is mainly composed of 3rd harmonics component. Then, a field current injection approach is presented, and calculate the magnitude and phase of the injected component, which serves as a quantitative analysis foundation for torque ripple suppression. Finally, the experimental results illustrate the superiority of the presented method in torque ripple optimization.

Modified Direct Torque Control Technique of Induction Motor for Torque Ripple and Common-Mode Voltage Reduction with Neutral-Point Voltage Balancing

Modified Direct Torque Control Technique of Induction Motor for Torque Ripple and Common-Mode Voltage Reduction with Neutral-Point Voltage Balancing

Correction to: Torque Tracking Improvement and Ripple Reduction Caused by Load Conditions and Speed Values for Direct Torque Control of IM Fed by a Two-Level Inverter

Correction to: Torque Tracking Improvement and Ripple Reduction Caused by Load Conditions and Speed Values for Direct Torque Control of IM Fed by a Two-Level Inverter

Torque ripple reduction for switched reluctance motors using global optimization algorithm

Torque ripple reduction for switched reluctance motors using global optimization algorithm

Design and Optimization of Double-Stator Vernier Permanent Magnet Motor With Improved Torque Characteristics Based on Flux Modulation Theory

In this article, based on flux modulation theory, torque characteristics improvement method is proposed for double-stator vernier permanent magnet (DS-VPM) motor. Also, the detailed torque production mechanism of DS-VPM motor is derived. Based on theoretical analysis results, key design parameters which possess significant influence on motor torque characteristics are selected to be further optimized purposefully. Non-dominated sorting genetic algorithm is then adopted to obtain increased output torque and reduced torque ripple of inner, outer, and total DS-VPM motor. Besides, based on finite-element analysis, motor performances before and after optimization are compared in detail. Finally, a prototype motor is built and corresponding experiments are carried out. Both theoretical analysis and experimental results verify the effectiveness of the proposed torque characteristics improvement method, which provides a potential research path for the design optimization of high-performance VPM motors.

A New Robust Direct Torque Control Based on a Genetic Algorithm for a Doubly-Fed Induction Motor: Experimental Validation

The parametric variation of nonlinear systems remains a significant drawback of automatic system controllers. The Proportional–Integral(PI) and Proportional–Integral–Derivative (PID) are the most commonly used controllers in industrial control systems. However, with the evolution of these systems, such controllers have become insufficient to compete with the complexity of the systems. This problem can be solved with the help of artificial intelligence, and especially with the use of optimization algorithms, which allow for variable gains in PID controllers that adapt to parametric variation. This article presents an analytical and experimental study of the Direct Torque Control (DTC) of a Doubly-Fed Induction Motor (DFIM). The speed adaptation of the DFIM is achieved using a PID controller, which is characterized by overshoots in the speed and ripples in the electromagnetic torque. The Genetic Algorithm (GA) within the DTC shows very good robustness in speed and torque by reducing torque ripples and suppressing overshoots. The simulation of the GA-DTC hybrid control in MATLAB/Simulink confirms the improvement offered by this strategy. The validation and implementation of this strategy on the dSPACE DS1104 board are in good agreement with the simulation results and theoretical analysis.

A Combinational Sequence Duty Ratio Control of SPV Fed Variable Speed Induction Motor Drive Using Field Oriented Control

This paper emphasizes the performance of solar photovoltaic (SPV) fed field-oriented control (FOC) based induction motor drive (IMD) using combinational sequence (CBS) based duty ratio control (DRC). The low-efficiency problem of SPV panels is resolved with the help of the maximum power point tracking (MPPT) algorithm. Here, the incremental conductance (INC) algorithm and the boost converter extract maximum power from the SPV system. Moreover, the control of IMD is performed using FOC and a 2-level 3-Φ inverter. Furthermore, the reduction voltage/current total harmonic distortion (THD) in IMD is achieved using PWM techniques. Here, the proposed CBS-DRC is a combination of switching sequences in every sector region. However, CBS's operation selects the less area of root mean square (RMS) of stator flux ripples (SFRs) to improve the voltage/current profile of the 3-Φ IMD. Consequently, the reduced torque ripple and speed variations are achieved with the proposed CBS-DRC compared to 0127 sequences. However, the switching sequences are implemented in real-time using the DSPACE DS-1104 controller. Also, a comparison of the overall performance of IMD using 0127 sequence DRC and the proposed CBS-DRC at various loading conditions is disclosed.

Torque Ripple Suppression for Permanent-Magnet Synchronous Motor based on Enhanced LADRC Strategy

Permanent-Magnet Synchronous Motor has shown advanced performance in the industry, but its smooth operation is affected by torque ripple. The conventional Linear Active Disturbance Rejection Controller (LADRC) has a strong anti-interference ability. However, this usually makes it more sensitive to measurement noise, reducing steady-state accuracy. This study proposes an Enhanced LADRC controller to obtain strong system disturbance and noise suppression performance. Firstly, the total disturbance differential signal is introduced into the Linear Extended State Observer to improve the anti-disturbance ability of the system, and the bandwidth parameter configuration method is used to reduce the number of parameters be adjusted in the controller to two. Second, A Fal-Filter is built through the nonlinear function and inserted into the controller to weaken the measurement noise. Finally, the simulation model is established on the dSPACE motor control platform, and the corresponding control algorithm is implemented. Simulation and experimental results show that the control scheme can significantly improve the phase current distortion and reduce torque ripple.