scholarly journals Harmonic Analysis on Torque Ripple of Brushless DC Motor Based on Advanced Commutation Control

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yanpeng Ji ◽  
Bin Li ◽  
Jingcheng Sun
Keyword(s):  
Harmonic Analysis ◽  
Influencing Factor ◽  
Torque Ripple ◽  
Current Harmonics ◽  
Phase Current ◽  
Brushless Dc ◽  
Harmonic Analysis Method ◽  
Permanent Magnet Brushless Dc ◽  
Relationship Of ◽  
The Relationship

This paper investigates the relationship between current, back electromotive force (back-EMF), and torque for permanent-magnet brushless DC (PM BLDC) motors under advanced commutation control from the perspective of harmonics. Considering that the phase current is the influencing factor of both torque and torque ripple, this paper firstly analyzes the effects of advanced commutation on phase current and current harmonics. And then, based on the harmonics of the phase current and back-EMF, the torque harmonic expressions are deduced. The expressions reveal the relationship of harmonic order between the torque, phase current, and back-EMF and highlight the different contribution of individual torque harmonic to the total torque ripple. Finally, the proposed harmonic analysis method is verified by the experiments with different speed and load conditions.

scholarly journals Equivalent Phase Current Harmonic Elimination in Quadruple Three-Phase Drives Based on Carrier Phase Shift Method

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2709
Author(s):  
Xuchen Wang ◽  
Hao Yan ◽  
Giampaolo Buticchi ◽  
Chunyang Gu ◽  
He Zhang
Keyword(s):  
Carrier Phase ◽  
Pulse Width Modulation ◽  
Torque Ripple ◽  
Current Harmonics ◽  
Phase Current ◽  
Harmonic Elimination ◽  
Three Phase ◽  
High Control ◽  
Machine Drives ◽  
Transportation Applications

Multiphase drives are entering the spotlight of the research community for transportation applications with their high power density and the possibility of high fault tolerance. The multi three-phase drive is one of the main types of multiphase drives that allows for the direct adoption of commercial three-phase converters and high control flexibility. The elimination of high-frequency current harmonics will reduce the flux linkage harmonics, torque ripple, vibration and noise in machine drives. Therefore, this work introduces a new method to the modelling of equivalent phase current in multi three-phase drives with the double integral Fourier analysis method. A new carrier-based pulse-width modulation (CPWM) method is introduced to reduce the equivalent phase current harmonics by applying proper carrier phase angle to each subsystem in the multi three-phase drives. The proposed angles of carrier signals are analyzed for quadruple three-phase drives, and the corresponding experimental results confirm the significance of the proposed phase-shifted CPWM method to eliminate the equivalent phase current harmonics.

scholarly journals Complete suppression of torque ripple in BLDC machines caused by back emf and dead time

2021 ◽  
Author(s):  
Miodrag Joksimovic ◽  
Emil Levi ◽  
Slobodan Vukosavic
Keyword(s):  
Dead Time ◽  
Torque Ripple ◽  
Internal Model Control ◽  
Complete Suppression ◽  
Brushless Dc Motors ◽  
Current Harmonics ◽  
Brushless Dc ◽  
Dc Motors ◽  
Model Control ◽  
Dead Time Compensation

<div>Abstract—This paper introduces a novel algorithm for suppresion of phase current harmonics in three-phase brushless dc motors caused by non-ideal back-emf waveform and dead-time effects. Proposed feedback acquisition chain obtains an exact information on all the relevant harmonics within each period of the fundamental. Design of the harmonic regulator based on the internal model control principle is given. The paper outlines the relevant details of implementation and the results of verification performed by both computer simulations and experimentally, using a laboratory prototype machine. Experimental results conducted in presence of non-sinusoidal back-emf and with erroneous dead time compensation prove the ability of the proposed solution to remove the stator current harmonics quickly, in just two fundamental periods.</div>

scholarly journals Computer Aided Modeling and Analysis of Five-Phase PMBLDC Motor Drive for Low Power High Torque Application

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
M. A. Inayathullaah ◽  
R. Anita
Keyword(s):  
Low Power ◽  
High Efficiency ◽  
Dynamic Performance ◽  
Torque Ripple ◽  
Performance Simulation ◽  
Modeling And Analysis ◽  
Brushless Dc ◽  
New Type ◽  
High Torque ◽  
Permanent Magnet Brushless Dc

In order to achieve high torque at low power with high efficiency, a new five-phase permanent magnet brushless DC (PMBLDC) motor design was analyzed and optimized. A similar three-phase motor having the sameD/Lratio (inner diameter (D) and length of the stator (L)) is compared for maximum torque and torque ripple of the designed five-phase PMBLDC motor. Maxwell software was used to build finite element simulation model of the motor. The internal complicated magnetic field distribution and dynamic performance simulation were obtained in different positions. No load and load characteristics of the five-phase PMBLDC motor were simulated, and the power consumption of materials was computed. The conformity of the final simulation results indicates that this method can be used to provide a theoretical basis for further optimal design of this new type of motor with its drive so as to improve the starting torque and reduce torque ripple of the motor.

scholarly journals Proposed Commutation Method for Performance Improvement of Brushless DC Motor

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6023
Author(s):  
Chang-Sung Jin ◽  
Chang-Min Kim ◽  
In-Jin Kim ◽  
Iksang Jang
Keyword(s):  
Performance Improvement ◽  
Acoustic Noise ◽  
Torque Ripple ◽  
Brushless Dc Motor ◽  
Efficiency Improvement ◽  
Current Harmonics ◽  
Brushless Dc ◽  
Motor Efficiency ◽  
Ac Motor ◽  
Three Phase

This study focused on the efficiency improvement and acoustic noise reduction of brushless DC (BLDC) motors by reducing current harmonics using a novel BLDC commutation method. To achieve these goals, we designed an improved 150° commutation method for a three-phase permanent magnet BLDC motor that can improve the current waveform. Although the 120° commutation method is generally employed for BLDC motors, an improved 150° commutation method is introduced to operate the BLDC with increased efficiency and acoustic noise similar to a brushless AC motor. This study investigated the attributes of various commutation methods, both theoretically and experimentally, to determine the optimal commutation method. The results of this study indicate that the improved 150° commutation method is optimal in terms of harmonic attributes and reduced torque ripple, allowing it to improve motor efficiency and reduce acoustic noise.

Solution for Data Growth Problem of MOLAP

2013 ◽  
Vol 321-324 ◽  
pp. 2551-2556
Author(s):  
Jian Xu ◽  
Yong Qiang Luo ◽  
Xin Xin Zhou
Keyword(s):  
Growth Factor ◽  
Data Storage ◽  
Influencing Factor ◽  
Query Performance ◽  
Close Relationship ◽  
Growth Problem ◽  
Relationship Of ◽  
The Relationship

Because MOLAP uses Multi-dimensional database (MDDB) to store data, there are limits to implement OLAP, such as data growth. Also, there is a close relationship between the influencing factor of MOLAP data growth and OLAP model, and the models will influence the size of cubes, also the performance and expansibility of OLAP system. This paper studies the approaches of MOLAP data storage organization, aggregate levels of dimension, compound growth factor (CGF), the relationship of query performance and percentage pre-calculated, and giving a brief analysis to how to use CGF to ravel out the data growth of MOLAP.

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