This paper presents a novel method to reduce commutation torque ripple in a position sensorless brushless dc (BLDC) motor drive. To compensate the commutation torque ripple considerably, conventional methods should know commutation interval, so that they need current sensors. However, the proposed method measures commutation interval from the terminal voltage of a BLDC motor, calculates a pulsewidth modulation (PWM) duty ratio using the measured commutation interval to suppress the commutation torque ripple, and applies to the calculated PWM duty ratio only during the next commutation. Experimental results verify that the proposed method implemented in an air conditioner compressor controller considerably reduces not only the pulsating currents but also vibrations of a position-sensorless BLDC motor

Commutation Torque Ripple Reduction in a Position Sensorless Brushless DC Motor Drive

The hard disk drive is one of the finest examples of the precision control of mechatronics, with tolerances less than one micrometer achieved while operating at high speed. Increasing demand for higher data density as well as disturbance-prone operating environments continue to test designers' mettle. Explore the challenges presented by modern hard disk drives and learn how to overcome them with Hard Disk Drive: Mechatronics and Control.Beginning with an overview of hard disk drive history, components, operating principles, and industry trends, the authors thoroughly examine the design and manufacturing challenges. They start with the head positioning servomechanism followed by the design of the actuator servo controller, the critical aspects of spindle motor control, and finally, the servo track writer, a critical technology in hard disk drive manufacturing. By comparing various design approaches for both single- and dual-stage servomechanisms, the book shows the relative pros and cons of each approach. Numerous examples and figures clarify and illustrate the discussion.Exploring practical issues such as models for plants, noise reduction, disturbances, and common problems with spindle motors, Hard Disk Drive: Mechatronics and Control avoids heavy theory in favor of providing hands-on insight into real issues facing designers every day.

Hard Disk Drive: Mechatronics and Control

A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

Power Conversion Device

Brushless DC (BLDC) motors and their drives have been increasingly considered in a broad range of applications due to their significant features. The implementation of these motors is possible thanks to firstly, the progress of permanent-magnet (PM) technologies which provide high efficiency, power density, and torque for these motors. Secondly, the structure and special features of these motors have prepared a basis for simpler control and smaller size compared to those with the same power. In this paper, the basic drives of BLDC motors have been reviewed in order to provide a useful reference for primary research in conventional methods of these types of motors. To present a proper insight to various drive techniques in these motors a systematic classification to control strategies with principles of these techniques has been made. In addition, computer simulations have been utilized in order to achieve a more accurate evaluation, provide the possibility of comparative analysis between various strategies, and place emphasis on the constraints and features of each method. Apart from the comparison of different methods of each strategy, a general comparison among the different methods of various strategies has been made based on the torque ripple, analysis of frequency, and losses of the BLDC motor drive as well as various applications of the different controlling methods. Moreover, considering the importance of electric vehicles (EVs) in industry, selection of the best controlling method for this type of applications together with energy regeneration has been discussed.

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Review of permanent-magnet brushless DC motor basic drives based on analysis and simulation study

This paper introduces four PWM modes used in sensorless brushless DC motor control systems, and analyzes their different influences on the commutation torque ripple in detail. The authors then select the best PWM mode in four given types to reduce commutation torque ripple of BLDC motors. Simulation and experimental results prove that the selection is both correct and practical.

The different influences of four PWM modes on the commutation torque ripples in sensorless brushless DC motors control system

A new compensation method and an algorithm to compensate the commutation torque ripple of the trapezoidal brushless DC motor with a permanent magnet rotor are put forward. The simulation and experiment results show that this method is correct and practical.

Pingping Zhu

Papers

A new method to minimize the commutation torque ripple in trapezoidal BLDC motor with sensorless drive