JoonSeon Ahn

The characteristic analysis of switched reluctance motor considering DC link voltage ripple on hand and soft chopping modes

Time-stepped voltage source finite element method (FEM) was used as a computational method to analyze switched reluctance motor considering freewheeling diodes and dc link voltage ripples on hard and soft chopping modes respectively. The phase currents and the dc link voltage ripples were also measured for the first time

Optimal magnet shape to improve torque characteristics of interior permanent magnet synchronous motor

Permanent magnet (PM) motor is the best choice in the application to a hybrid vehicle. PM configuration is one of the critical design points for the application. This paper presents the effect of PM shapes on the motor performance, especially sinusoidal induced voltage. The proposed design by finite element method has been confirmed by comparing emf wave form, harmonics, reluctance torque, and rated torque between conventional and models. Quantitative comparison of the characteristics for interior permanent magnet synchronous motor of four models is shown. The four models are lateral magnet, V-shape magnet, modified V-shape magnet, and C-shape magnet.

A study on digital control of 3-D.O.F. BLDCM using LabVIEW

In this paper, authors are proposed drive system for BLDCM using motor drivers based on LabVIEW. Most researchers generally use MATLAB/SIMULINK program as computer simulation tool for their control system design. These control system must be coded to the motor drivers using program language such as C for its verification. We developed drive system using LabVIEW, it is able to complete whole process from control system design to verification of control system without program coding. Authors also proposed power conversion stack designed for LabVIEW controller and BLDCM drive.

The high-speed operation of single phase switched reluctance motor considering magnetic saturation

In the high-speed operation of SRM, the conventional pulse width modulation (PWM) drive method is not available because of the limitation of switching speed; therefore the single-pulse drive method is commonly employed. On the contrary, the use of the single-pulse drive method cannot avoid the overcurrent in the low-speed operation because of the insufficient back emf and the difficulty of duty control. With these reasons, the switching method is commonly changed from PWM at the low-speed operation to the single-pulse method at the high-speed operation. In the fan application, the required load torque increases as a square of the fan speed; it requires more current for the torque generation. Therefore at the mode transition between PWM and single-pulse drive, it is unavoidable that the phase current rapidly increases if the nonlinearity of inductance to the current is not considered. In this paper, by using finite element method (FEM) which is considered with the nonlinearity of the inductance with respec...

Dynamic characteristics analysis of linear dc motor for the electric screen door

In order to simulate the dynamic characteristics, we have developed a method of calculating the force of the linear dc motor screen door system which is using three-dimensional data of flux density in air gap from finite element analysis. We use the coil mesh data to calculate Lorentz forces of each coil. Then they are used for the dynamic characteristic analysis. The simulated dynamic characteristic is compared with experimental value.

A Study on the Sensorless Control of Synchronous Reluctance Motor using Trigonometric Function

Recently, SynRM has been focused by many researchers and there has been a lot of works for the industrial application of SynRM. In spite of several merits of SynRM, the information of exact rotor position is also required to perform the precise torque control, which causes the increment of cost and demerits SynRM to use in industrial application. Therefore, we studied sensorless control algorithm for the torque control of SynRM to overcome the demerits. Specially we proposed simple algorithm to estimate rotor position using trigonometric function, verified with computer simulation and experiment.

Zero Power Control for an Attraction Type Magnetic Levitation System using Disturbance Observer

In this paper, authors performed improvement of control characteristics of an attraction type magnetic levitation system. The attraction type magnetic levitation system has an inherent instability in the system, therefore its controller must have not only proportional-integral gain but also differential gain additionally. In this paper, authors were proposed control algorithm using disturbance observer(DOB) on feedback signal. The computer simulation and experiments were performed for its verification.

Novel Rotor Shape of Switched Reluctance Motor for Windage Loss Reduction

This paper presents a novel switched reluctance motor rotor shape which has ribs between the rotor salient poles on the rotor outer surface. The conventional switched reluctance motor and the proposed rotor shape which is an aerodynamically cylindrical rotor but magnetically same as a conventional rotor are presented. Using this rotor, the windage loss can be reduced dramatically at high speed.

A New Torque Ripple Analysis Method for Permanent Magnet Assisted Synchronous Reluctance Motor by using Load Angle Characteristic

This paper presents a new and efficient method for torque ripple calculation from an analysis of torque angle curve by FEM. An experiment for the verification of proposed method is performed.The torque angle range in which torque ripple is minimized is found.

PARAMETRIC VARIANCE CONSIDERATION IN SPEED CONTROL OF FLUX REVERSAL MACHINE

The flux reversal machine (FRM) is a new machine that has a simple robust rotor with a permanent magnet installed stator. [Y. Liao et al., 1995][T.A. Lipo et al., 1997] However, the parameters of the FRM are dependant on the position of the rotor, operating temperature and magnetic saturation of the motor core. To obtain a robust performance of the single phase FRM, a control method that introduces an internal model of the motor is suggested for robustness against parameter variance and disturbance. The suggested control method is verified by both computer simulation and experiments