Torque Ripple Minimization Technique Research Articles

Five-Level Inverter-Fed Model Predictive Current Control for a Five-Phase PMSM Drive

In this paper, a five-level inverter-fed Model Predictive Current Control (MPCC) of Five-Phase Permanent Magnet Synchronous Motor (PMSM) Drive is proposed to enhance the performance of the drive by reducing the torque ripples. The MPCC method provides a good steady-state performance and also this method does not require a weighting factor. Among the various torque ripple minimization techniques, the multilevel inverters attracted more attention in electric drives due to rapid development in semiconductor technology. The performance analysis of a five-level (5L) inverter-fed five-phase PMSM drive is compared with two-level (2L) and three-level (3L) inverter drives under various operational conditions. The effectiveness of the proposed method is analyzed using MATLAB/SIMULINK software and also implemented using a real-time simulator.

A Review of the State of the Art of Torque Ripple Minimization Techniques for Permanent Magnet Synchronous Motors

Industrial applications such as automation, robots, and electric vehicles are widely employing permanent magnet synchronous motors (PMSM) due to inherent characteristics such as high torque to power ratio, low maintenance, high efficiency, and wide operating range. However, PMSM drives can suffer from unwanted torque ripples caused by periodic disturbances of the electromagnetic effect. First, this paper analyses the sources of torque ripple in PMSMs. Second, the torque measurement techniques of the PMSM including torque sensors, torque observers, and indirect measurement methods are discussed to highlight their shortcomings. Third, this paper categorizes and summarizes advanced control-based torque ripple minimization (CB-TRM) techniques for the PMSM by critically evaluating their impacts. These CB-TRM techniques actively control the current waveforms to ensure smooth torque generation and mitigate the effects of torque ripples. Finally, the paper concludes by discussing remaining research questions and opportunities for future research on TRM techniques for PMSMs.

Arithmetic optimization algorithm based torque ripple minimization technique for solar fed sensorless BLDC drive for domestic applications

The high efficiency feature of the Brushless Direct Current (BLDC) motor can be used for industrial drive applications to minimize the power consumption. The BLDC motor suffers with torque ripple issues during medium and high-speed applications which minimizes the use of BLDC in various applications. This paper proposes an Arithmetic Optimization Algorithm (AOA) tuning to enhance the gain of the controller to mitigate the torque ripple of the BLDC drive. This improves the application of BLDC in domestic and industrial applications viz., compressor, air conditioner. The proposed algorithm is tested in a solar fed compressor using MATLAB simulation and the results shows that the AOA advances the behavior of BLDC motor at different speed, torque conditions with minimum power consumption and low vibrations.

Torque Ripple Minimization Technique of Position Sensorless BLDC Motor for Variable Speed Drives

Brushless Direct Current (BLDC) motors are advantageous because of their higher efficiency, higher speed operations and higher power density. Industrial applications demand BLDC motors free from torque ripple. The torque ripple is due to the unequal commutation period between the energised phase and unenergized phase current. It is a perilous problem in sensorless BLDC drive as it leads to speed oscillations, acoustic noise, serious faults, and vibration in machines. The torque ripple can be reduced either by improving motor design parameter or by improving the motor control strategy. This paper proposes a Proportional Integral (PI) controller-based control scheme for a cuk converter driven sensorless BLDC motor to reduce the torque ripple. The proposed scheme invokes Zero Crossing Point (ZCP) detection with back emf sensing approach. The presence of inductor reduces the ripple in the input and output currents. The performance of the strategy is verified using MATLAB R2018a Simulink for different operating conditions of a BLDC drive and the results prove that the recommended scheme decreases the torque ripple compared to the conventional scheme.

A Mathematical Torque Ripple Minimization Technique Based on a Nonlinear Modulating Factor for Switched Reluctance Motor Drives

This article presents a method to reduce the torque ripple in an 8/6 four-phase switched reluctance motor (SRM). The proposed scheme introduces a nonlinear modulating factor dependent on the rotor position and magnitude of the phase currents. This factor manipulates the currents in two adjacent phases during commutation and reduces the torque ripple effectively. Unlike the conventionally available torque-sharing functions, the proposed method instantaneously modulates every phase current obtained mathematically based on the other phase current in order to maintain the net torque constant. The proposed method requires minimal offline analysis and offers maximum possible torque with a minimal ripple. The method is simple and easy to implement due to a low computational burden. The proposed algorithm is implemented using MATLAB/Simulink software and is also validated experimentally on a 0.6-hp 8/6 SRM using a field-programmable-gate-arrays-based hardware setup developed in the laboratory. Typical results are presented and compared with the existing techniques. A torque ripple of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\approx 8\%$</tex-math></inline-formula> has been achieved.

On the Electromagnetic Performance Prediction of Turbo Synchronous Condensers Based on Wound-Field Flux Switching Machine Design

The revival of the old synchronous condenser (SC) technology is presently occurring. Hence, this study is proposed on the electromagnetic design and evaluation of turbo wound-field flux switching machines (WF-FSMs) for SC operation, for the first time. Unlike classical wound-field rotating machines, WF-FSMs do not need brushless exciters while possessing a robust topology. A design process based on the frozen permeability technique in static 2-D finite element analysis script-based package, which enhances both iterative and analytic adjudications, is proposed to accurately predict the SC operation. To attain the specific design requirements (~300 MVAR, 16 kV), a global-optimized model (GOM) of the SC machine is obtained through a stochastic optimization process involving multiple objectives. Based on the GOM, simple torque ripple minimization techniques are implemented, from which a final benchmark design is selected. The proposed SC analytical design procedure is then tested and the expected V-curves clearly obtained. The whole design approach is further verified by experimenting on a small-scale prototype, which when synchronized to the grid, confirms the novelty and feasibility of the proposed SC design and operation.

An Online Torque Ripple Minimization Technique for IPMSM Drives: Fuzzy System-Based d-Axis Current Design Approach

This article proposes an online torque ripple minimization (TRM) technique using a fuzzy system (FS)-based d-axis current design for interior permanent magnet synchronous motor (IPMSM) drives. Existing control-based TRM techniques generally employ optimization algorithms to design the dq-axis currents that attenuate the torque ripples. However, complex iterations applied for the optimization algorithms increase computational complexity, which limits the applicability of such TRM techniques under transient state of the IPMSM drives. Unlike with existing methods, the proposed TRM technique designs reference d-axis current using a computationally efficient algorithm and remarkably minimizes the torque ripples. Moreover, the reference d-axis current is designed online based on an FS to keep the stator current of the IPMSM inside the rated value, especially at the transient state. The proposed TRM strategy is validated through simulation and experimental investigations by using a MATLAB/Simulink software and a prototype IPMSM drive with TI TMS320F28335 digital signal processor. Comparative theoretical and experimental investigations prove that the proposed TRM technique is computationally efficient and ensures more reduced ripples in the electromagnetic torque and dq-axis currents with d-axis current significantly close to zero than conventional maximum torque per ampere based technique without TRM and conventional current control-based TRM technique under critical load conditions.

Influence of Laminating Materials and Modified Pole Shapes on the Performance of Segmented Rotor Switched Reluctance Motor

This work deals with the torque ripple minimization techniques of Segmented Rotor Switched Reluctance Motor (SSRM) for cooling fan application. Torque ripple, acoustic noise and vibration are factors resisting the segmented rotor SRM. To overcome this, stator and rotor pole modifications along with the effects of laminating steel material have been analyzed for the performance improvement of the machine. The performance of the machine with different laminating steel materials such as M19, M850-65A, M890-50d and M43 are compared with the conventional CR-10 steel material. With respect to pole shape modifications the analysis has been performed by considering stator pole taper, stator pole arc, rotor segement structure and rotor pole depth. The results highlight the influence of structural modifications and material properties on the performance of the motor. The results of electromagnetic analysis disclose that the segmented rotor configuration with M890-50d material exhibits superior electromagnetic characteristics.

Improved Torque Ripple Minimization Technique With Enhanced Efficiency for Surface- Mounted PMSM Drives

This paper proposes an improved torque ripple minimization (TRM) method using model-based loss minimization (LM) control to reduce the torque ripples and enhance the efficiency for surface-mounted permanent magnet synchronous motor (SPMSM) drives. The conventional SPMSM drives usually achieve the maximum torque per ampere (MTPA) control by applying the zero d-axis current (ZDC) and ignore an actual core loss resistance in the controller design. Unlike the conventional MTPA method, the proposed TRM selects the appropriate d-axis current value by making the derivative of the electromagnetic torque equal to zero in the SPMSM drives. Consequently, the proposed method can improve the torque ripples and efficiency compared to the conventional MTPA. Using the proportional-integral (PI) controllers, comparative experimental verifications between the proposed model-based TRM, the conventional model-based MTPA, and the conventional model-based LM are performed through a prototype SPMSM drive with a TI TMS320F28335 digital signal processor (DSP).

Methods of Torque Ripple Minimization Techniques on Switched Reluctance Motor

In recent decades, Switched Reluctance Motor (SRM) drive has proved to be an attractive alternate for the conventional industrial drives. Many published research works have proved that SRM drives finds significant application in almost all industrial sectors. This paper presents a comprehensive review on various control strategies of SRM drive implemented in literatures. The objective of this review is to identify the accurate control strategies for controlling the SRM speed and torque. This paper also reviews the various strategies for minimization of the torque ripples, acoustic noise and vibration in SRM

Active Current Harmonic Suppression for Torque Ripple Minimization at Open-Phase Faults in a Five-Phase PMa-SynRM

This paper presents an active phase current harmonic suppression method to smartly and adaptively perform torque ripple minimization (TRM) under open-phase fault conditions in a five-phase permanent-magnet-assisted synchronous reluctance motor (PMa-SynRM). The five-phase machine is gaining increasing attention due to its promising fault-tolerant and wide-speed operation capabilities. However, during the fault-tolerant operation, the torque ripple is substantially increased with dangerous vibrations. Until now, most TRMs have been primarily performed to maintain the constant magnetomotive force while only analyzing its fundamental harmonic. However, large torque variations are also caused by unexpectedly modulated high-order harmonic fluctuations that are challenging to predict. This fluctuation in current harmonics is highly destructive to reluctance machines due to its higher nonlinearity. To address this critical challenge, a real-time active TRM technique has been proposed that will be smartly adaptive to identified harmonic fluctuations. To achieve this, the proposed TRM solution systematically consists of three major steps: first, active harmonic identification; second, harmonic injection; and third, vector rotation of phases. To precisely identify fluctuating harmonics in a real time, a high precision but compact correlation-based monitoring algorithm has been proposed. A detailed theoretical analysis has been carried out through a finite-element analysis. The experimental tests are conducted to validate the proposed theory through a five-phase PMa-SynRM drive controlled by Texas Instruments DSP F28335.

Comparative Performance Analysis of Reference Voltage-Controlled Pulse Width Modulation for High-Speed Single-Phase Brushless DC Motor Drive

The recent advancements in power switching device material and manufacturing technology have enabled the design of highly efficient and compact high-speed motor direct drives. The use of high-switching frequency pulse width modulation in these drives provides speed and torque control capabilities and it can also serve as an effective phase current shaping method for torque ripple minimization. This paper builds upon the previous paper introducing a torque ripple minimization technique for gallium nitride high-electron mobility transistor-based high-speed single-phase brushless dc motor drive. It presents an in-depth performance analysis in comparison with the conventional high-speed control techniques. Four different high-speed control techniques are implemented and tested to quantify the maximum speed, efficiency, torque ripple, and vibration. The vibration of the motor drive is measured using a microelectromechanical systems accelerometer with a ferroelectric random access memory for high-speed data acquisition with the maximum bandwidth of 1 kHz.

Comparative study of torque ripple minimization techniques for a three-phase switched reluctance motor

Comparative study of torque ripple minimization techniques for a three-phase switched reluctance motor

Artificial neural controller for torque ripple control and maximum power extraction for wind system driven by switched reluctance generator

Abstract Torque ripples and maximum power tracking form the most important problems facing Wind Energy Conversion System (WECS). This paper presents modified toque ripple minimization algorithm of four phases 8/6 poles Switched Reluctance Generator (SRG) using Artificial Neural Network (ANN) control. This control algorithm is based on optimum profiling of the generator phase currents during overlapping periods. The paper, also, introduces new Maximum Power Point Tracking (MPPT) for SRG by modifying the classical Hill Climb Searching (HCL) technique using ANN which is designed to emulate the PI controller for closed loop operation under different wind speeds. Moreover multi level diode clamped inverter is used for connecting SRG to the grid in order to reduce Total Harmonic Distortion (THD) to about 1.45% and reduce filter size. The simulation results show good agreement and support the feasibility of the proposed torque ripple minimization and MPPT techniques.

A Non-Unity Torque Sharing Function for Torque Ripple Minimization of Switched Reluctance Generators in Wind Power Systems

This paper deals with a new torque ripple minimization method for a Switched Reluctance Generator (SRG). Although, the SRG has many advantages including simple and robust construction, and high power density as a generator, it has not been widely employed in the industry. One of the major drawbacks of the SRG is its high torque ripple that results in high noise operation of the generator. In this paper, a non-unity Torque Sharing Function (TSF) is proposed to minimize the torque ripple over a wide speed range of operation. Simulations as well as experimental results are presented to verify the effectiveness of the proposed torque ripple minimization technique.

An Adaptive-Filter-Based Torque-Ripple Minimization of a Fuzzy-Logic Controller for Speed Control of IPM Motor Drives

This paper presents an adaptive-filter-based torque-ripple minimization (TRM) of a fuzzy-logic controller (FLC) for speed control of an interior permanent magnet (IPM) motor drive. A simple and effective first-order digital infinite impulse response filter is utilized to reduce the torque ripples introduced by the FLC. The gain of the filter is adapted online based on the magnitude of the torque ripple. The optimal position of the filter in the complete drive is also determined for effective TRM. The various sources of torque pulsations in a practical electric-machine drive are described. The main causes of the torque ripple in an FLC are also explained. A simulation model for closed vector control of an FLC-based IPM motor drive incorporating the proposed TRM technique is developed in Matlab/Simulink. The complete drive is also experimentally implemented using digital signal processor board DS1102 for a laboratory 1-hp IPM motor. The effectiveness of the proposed technique is investigated, both in simulation and experiment, at different operating conditions. It is found that the performance of the FLC-based IPM drive is improved significantly with the proposed TRM technique.

Real time implementation of viable torque and flux controllers and torque ripple minimization algorithm for induction motor drive

Field oriented control (FOC) and direct torque control (DTC) are becoming the industrial standards for induction motors torque and flux control. This paper aims to give a contribution for a detailed comparison between these two control techniques, emphasizing their advantages and disadvantages. The performance of these two control schemes is evaluated in terms of torque and flux ripple and their transient response to step variations of the torque command. Moreover, a new torque and flux ripple minimization technique is also proposed to improve the performance of the DTC drive. Based on the experimental results, the analysis has been presented.

Current shapes leading to positive effects on acoustic noise of switched reluctance drives

A torque ripple minimization technique for switched reluctance motors is shown in this paper. Precalculated current shapes are applied to reduce torque ripple and to raise the degrees of freedom of the application in the commutation region. The optimization criteria for this region can be chosen freely. Therefore, it is possible to take positive effect to some motor characteristics like power losses, mechanical vibrations or acoustic noise.