• Title, Summary, Keyword: Average torque

Search Result 240, Processing Time 0.041 seconds

CURRENT CONTROL ALGORITHM TO REDUCE TORQUE RIPPLE IN BRUSHLESS DC MOTORS

  • Lee, Kwang-Woon;Park, Jung-Bae;Yeo, Hyeong-Gee;Yoo, Ji-Yoon;Jo, Hyun-Min
    • Proceedings of the KIPE Conference
    • /
    • /
    • pp.380-385
    • /
    • 1998
  • This paper proposes a current control algorithm to reduce the torque ripple to commutation in unipolar PWM inverter-fed trapezoidal brushless dc motor drives. In this paper, we analyze the average voltage variation of the conducting phase due to commutation, and design a current controller to compensate for the average voltage variation. The proposed method predicts the duration of commutation to reduce the torque ripple due to over-compensation. Experimental results are presented that validate the proposed method.

  • PDF

Data Interpolation and Design Optimisation of Brushless DC Motor Using Generalized Regression Neural Network

  • Umadevi, N.;Balaji, M.;Kamaraj, V.;Padmanaban, L. Ananda
    • Journal of Electrical Engineering and Technology
    • /
    • v.10 no.1
    • /
    • pp.188-194
    • /
    • 2015
  • This paper proposes a generalized regression neural network (GRNN) based algorithm for data interpolation and design optimization of brushless dc (BLDC) motor. The procedure makes use of magnet length, stator slot opening and air gap length as design variables. Cogging torque and average torque are treated as performance indices. The optimal design necessitates mitigating the cogging torque and maximizing the average torque by varying design variables. The data set for interpolation and ensuing design optimisation using GRNN is obtained by modeling a standard BLDC motor using finite element analysis (FEA) tool MagNet 7.1.1. The performance indices of the standard motor obtained using FEA are validated with an experimental model and an analytical method. The optimal design is authenticated using particle swarm optimization (PSO) algorithm and the performance indices of the optimal design obtained using GRNN is validated using FEA. The results indicate the suitability of GRNN as an interpolation and design optimization tool for a BLDC motor.

Characteristics Analysis for Reduction of Cogging Torque in a Novel Axial Flux Permanent Magnet BLDC Motor (평판형 영구 자석 BLDC 전동기의 코깅 토크 저감은 위한 특성 해석)

  • Jo, Won-Young;Lee, In-Jae;Kim, Byung-Kuk;Kim, Tae-Hyun;Hwang, Dong-Won;Cho, Yun-Hyun;Koo, Dae-Hyun
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1180-1182
    • /
    • 2005
  • In this paper, the design and field analysis of the novel axial flux type permanent magnet(AFPM) motor with double stator and single rotor are investigated. The various design schemes of AFPM based on 3D finite element method are proposed. The effects of slot shapes, various magnetization of PM, and skewing on the cogging torque and average torque have been investigated in detail. From the results, we can improve the cogging torque and average torque characteristics.

  • PDF

Tilling Load Characteristics and Power Requirement for Rotary Tillers (로우터리 경운(耕耘)의 부하특성(負荷特性) 및 소요동력(所要動力)에 관(関)한 연구(硏究))

  • Choi, Kyu Hong;Ryu, Kwan Hee
    • Journal of Biosystems Engineering
    • /
    • v.9 no.2
    • /
    • pp.27-36
    • /
    • 1984
  • This study was carried out to investigate the effects of the tilling depth, tilling travel speed and soil shear stress on the tilling load characteristics and power requirement for rotary tillers. The results obtained from the study are summarized as follows. 1. The average and maximum PTO torque increased as the tilling depth, tilling pitch and soil shear stress increased. A multiple linear regression equation to estimate the average PTO torque in terms of the above parameters was developed. 2. The ratios of maximum PTO torque to the average torque were in the range of 1.17 to 1.65 for the various tilling conditions tested. The variation in PTO torque increased greatly as the tilling pitch and soil shear stress increased, but decreased as the tilling depth increased. 3. Power requirement for the PTO shaft increased with the tilling depth, travel speed and soil shear stress, but decreased slightly as the tilling pitch increased. A multiple linear regression equation to estimate power requirement for the PTO shaft in terms of the above parameters was developed. 4. The specific power requirement for the rotary tiller was in the range of $0.008-0.015ps/cm^2$ for the various tilling conditons tested. The specific tilling capacity decreased as the tilling depth and soil shear stress increased, but increased with the tilling pitch. A multiple linear regression equation to estimate the specific tilling capacity in terms of the above parameters was developed.

  • PDF

Improvement of Torque Characteristics of a Rotatory Two-Phase Transverse Flux Machine Optimizing the shape of Rotor Pole (자석 형상 최적화를 통한 축방향 이상 횡자속형 전동기의 토크 특성 향상에 관한 연구)

  • Ahn, Hee-Tae;Jang, Gun-Hee;Chang, Jung-Hwan;Chung, Shi-Uk;Kang, Do-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.286-292
    • /
    • 2008
  • Transverse flux machine (TFM) has been developed to drive a machine of large input power at low-speed. However, it has complicated structure and large torque ripple due to its inherent structure In this paper the characteristics of torque of a rotatory two-phase TFM are analyzed by using the 3-dimensional finite to element method and optimal design. This research shows that one of the effective design variables is the skew angle of permanent magnet. The skew angles of permanent magnet are optimized by using a Progressive Quadratic Response Surface Method (PQRSM). It also shows that the proposed optimal skew magnet not only increases average torque but also decreases torque ripple of a rotatory two-phase TFM.

  • PDF

Design of Switched Reluctance Motor for Minimizing the Torque Ripple (스위치드 릴럭턴스 전동기의 토오크 리플 저감 설계)

  • Kim, Youn-Hyun;Choi, Jae-Hak;Kim, Sol;Lee, Ju;RhYu, Se-Hyun;Sung, Ha-Kyung;Im, Tae-Bin;Borm, Jin-hwan
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.51 no.7
    • /
    • pp.339-350
    • /
    • 2002
  • Pole arcs, turn-on angle, and turn-off angle are major design factors, which affects Switched Reluctance Motor's torque performance. If these design factors are considered independently, the enhancement of SRM performance is restricted. Therefore, we need to consider pole arcs, turn-on angle and turn-off angle at the same time, when we design SR. In this paper, we analyze how these factors affect to torque ripple and average torque by using dynamic Finite Element Method(FEM) with derive circuit and present the good design results according to the various speeds. Especially, we formulate turn-on and turn-off angle from a voltage equation and present effective design range.

Design and Characteristic Analysis for High-speed Interior Permanent Magnet Synchronous Motor with Ferrite Magnet (페라이트 영구자석을 갖는 고속 매입형 영구자석 전동기의 특성해석 및 설계)

  • Park, Hyung-Il;Shin, Kyung-Hun;Yang, Hyun-Sup;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.11
    • /
    • pp.1806-1812
    • /
    • 2016
  • We propose an interior permanent magnet syhchronous motor (IPMSM) with arc-shape ferrite permanent magnets (PMs) as a substitute for the rare-earth permanent magnet, and determine its optimal design through parametric study. First, we use 2D finite element analysis to analyze 4-poles and 6-slots initial model according to performance requirements and design parameters. The current angle of the maximum average torque considered in the analysis is different compared with the current angle of the minimum torque ripple. Thus, the parametric study for optimal rotor design is performed by varying the thickness and the offset radius of the PMs according to current angle. In particular, a narrow bridge is required in conventional IPMSM for reducing flux leakage; however, the increase in cogging torque in the analysis model saturates the narrow bridge (large offset radius). Therefore, we suggest an appropriate shape considering limiting conditions such as DC link voltage, average torque, torque ripple, and cogging torque taking into account performance requirements.

Measuring the Average Torque according to Exciting Region of Single Phase SRM (단상 SRM의 여자구간에 따른 평균 토크 측정)

  • Kim Yong-Heon;Lee Eun-Woong;Lee Jong-Han;Lee Hyeon-Woo;Kim Jun-ho
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.989-991
    • /
    • 2004
  • There are many elements that affect the average torque of the single phase SRM. It is related with the stator and rotor pole arcs, the dwell angle of the exciting current, the turn on/off angle, etc., Most of all, the turn on/off angle is affect the design procedure of the driving and control circuit. So, in this study, it is intend to analyze the effect that the variations of the turn on/off angle affects the average torque. and then this analyses will be used to design the control driver of the single phase SRM.

  • PDF

Interaction of internal forces of interior beam-column joints of reinforced concrete frames under seismic action

  • Zhou, Hua;Zhang, Jiangli
    • Structural Engineering and Mechanics
    • /
    • v.52 no.2
    • /
    • pp.427-443
    • /
    • 2014
  • This paper presents detailed analysis of the internal forces of interior beam-column joints of reinforced concrete (RC) frames under seismic action, identifies critical joint sections, proposes consistent definitions of average joint shear stress and average joint shear strain, derives formulas for calculating average joint shear and joint torque, and reports simplified analysis of the effects of joint shear and torque on the flexural strengths of critical joint sections. Numerical results of internal joint forces and flexural strengths of critical joint sections are presented for a pair of concentric and eccentric interior connections extracted from a seismically designed RC frame. The results indicate that effects of joint shear and torque may reduce the column-to-beam flexural strength ratios to below unity and lead to "joint-yielding mechanism" for seismically designed interior connections. The information presented in this paper aims to provide some new insight into the seismic behavior of interior beam-column joints and form a preliminary basis for analyzing the complicated interaction of internal joint forces.

The Multi-objective Optimization of Switched Reluctance Motor (스위치드 릴럭턴스 전동기의 다중목적함수의 최적화 방법 연구)

  • Choi, Jae-Hak;Shin, Hyun-Hun;Lim, Jin-Jae;Lee, Ju;Lee, Jung-Ho;Baek, Soo-Hyun
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.118-120
    • /
    • 2002
  • In this paper, a multi-object optimization based on a progressive quadratic response surface method (PQRSM) and a time stepping finite element method (FEM) is proposed. The new PQRSM and FEM are able to decide optimal geometric and electric variables of the switched reluctance motor (SRM) with two objective functions: torque ripple minimization and average torque maximization. The result of the optimum design for SRM show an improved performance of motor and a relationship between torque ripple and average torque.

  • PDF