• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.2
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• pp.150-156
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• 2004

Although permanent magnet single phase synchronous motor which starts and runs through single phase voltage source has high efficiency, it is difficult to determine the rotating direction. In this paper, the starting characteristics of the capacitor-run single phase synchronous motor has been studied. The stator has same structure with the capacitor-run single phase induction motor, however the rotor consists of permanent magnet. In this case, the starting conditions according to the rotor and stator conditions are determined and the direction of the motor can be determined. From these results, it is desired that the proposed motor can be applied to the loads like the fans which has low starting torque.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.167-170
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• 1999

In this paper, we operate Synchronous Reluctance Motor(SynRM) using the two-phase conduction method. Acually SynRM is operated by the sinusoidal PWM method but in home-appliance there is many restrictions of making the motor such as the method of winding, the shape of rotor etc. Therefore it is possible that there is little difference of performance between the two-phase conduction method and the sinusoidal PWM method. In this paper the characteristics of motor noise will be analyzed especially in the case of using the two-phase conduction method by experiment results.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.5-9
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• 1989

In this paper, while 2-or 3-phase induction motor is driven with balance and no noise driving at dynamic and steady state condition. Single-phase induction motor is driven with pulsating torque except specific driving point. So we analyze the reason of producing pulsating torque with the view of unsymmetring concept. These results are applied to the design of high efficincy, high quality single-phase induction motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.138-147
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• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.2
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• pp.58-64
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• 2004

Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, in the user power distribution systems, most of the loads are single & three phase and unbalanced, generating voltage unbalance. Voltage unbalance is a condition in a polyphase system in which the rms values of the line-to-line voltages or the phase angles between consecutive line-to-line voltages, are not all equal. Slight voltage unbalance generates a disproportionately high current unbalance at the motor stator winding. This paper presents a scheme on operation states of a three-phase induction motor under unbalanced voltages. The three-phase voltages applied to the stator winding of the studied induction motor are controlled by respectively adjusting the magnitude and phase angle of each phase. The voltage unbalanced factor(VUF) of the three-phase source voltages can then be varied to examine the different values of VUF on machine's operation characteristics.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.1
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• pp.21-32
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• 2017

Objective : The purpose of this study is to explore the effectiveness of a perceptual motor program in promoting visual motor and motor control outcomes in a child with Attention-Deficit/Hyperactivity Disorder (ADHD) who is enrolled in an elementary school. Methods : The subject is 8-year-old boy who was diagnosed with ADHD but did not receive medication. Research design is a single-subject A-B-A(follow-up). Baseline and follow-up phase were 3 sessions and intervention phase were 8 sessions. After performing 40 minutes of free play on the baseline A and follow-up A, we used the copying subtest of the Korean Development Test of Visual Perception 2 (K-DTVP-2) for evaluating visual motor integration skill and the rope jumping subtest for motor skill. After providing the perceptual motor activity in intervention phase B, copying and ropejumping were performed. Results : The standard scores of the Copying for measuring visual motor integration skill were poor at an average of 4.7 points at baseline phase A, but maintained an average of 9.6 points at intervention phase B and an below average of 7.7 points at the follow-up phase A. In the Rope jumping for the motor skill, it was increased by 4.3 times in the baseline phase A and 5.9 times in the intervention phase B, but slightly decreased by 5 times in the follow-up phase A. Conclusion : This study suggests that perceptual motor program has a positive effect on visual motor and motor function of ADHD children.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2194-2200
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• 2014

This paper presents a design of novel 2-phase 6/5 switched reluctance motor (SRM) for an air-blower application. This type of motor is suitable for the applications that require high speed and only one directional rotation as air-blower. The desired air-blower is unidirectional application, and requires a wide positive torque region without torque dead-zone. In order to get a wide positive torque region without torque dead-zone during phase commutation, asymmetric inductance characteristic with non-uniform air-gap is considered. The proposed motor can be operated at any rotor position. The proposed 6/5 SRM uses short flux path technique that achieved by means of winding configuration and lamination geometry. The purpose of short flux path is to reduce the core loss and the absorption MMF in the stator. The proposed 2-phase 6/5 SRM is verified by finite element method (FEM) analysis and Matlab-Simulink. In order to verify the design, a prototype of the proposed motor was manufactured for practical system.

• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.485-493
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• 2007

This paper deals with the problem of detection of induction motor incipient faults. Artificial Neural Network (ANN) approach is applied to detect two types of incipient faults (1). Interturn insulation and (2) Bearing wear faults in single-phase induction motor. The experimental data for five measurable parameters (motor intake current, rotor speed, winding temperature, bearing temperature and the noise) is generated in the laboratory on specially designed single-phase induction motor. Initially, the performance is tested with two inputs i.e. motor intake current and rotor speed, later the remaining three input parameters (winding temperature, bearing temperature and the noise) were added sequentially. Depending upon input parameters, the four ANN based fault detectors are developed. The training and testing results of these detectors are illustrated. It is found that the fault detection accuracy is improved with the addition of input parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.465-470
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• 2001

Two-phase BLDC(brushless DC) motor has larger torque ripple than three-phase BLDC motor because of its unique skeleton-type structure. An electronic switching mechanism to change the current-direction of the BLDC motor can be a source of vibration as well as unbalanced rotor weight. A proper switching timing which makes less vibrations was considered by changing the position of sensing element around the center of rotation. Also, the current of the motor was measured for the calculation of the motor efficiency. From the vibration test results and with the consideration of the motor efficiency, an optimal switching position of the Hall sensor was found.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_2
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• pp.325-332
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• 2024

Contemporary power systems demand efficient and sustainable technologies. Single-phase induction motors, while widely used, face efficiency challenges due to inherent rotor losses. Proposed solutions include the Line-start Permanent Magnet Synchronous Motor (LSPMSM), leveraging permanent magnets for enhanced energy density but facing demagnetization and cost issues. Alternatively, the Line-start Synchronous Reluctance Motor (LSRM) operates as a hybrid motor without permanent magnets, reducing rotor losses and potentially improving efficiency. This paper focuses on designing an LSRM rotor for air conditioner compressors, analyzing start-up characteristics and efficiency through finite element analysis. A comparative study with single-phase induction motors provides insights for future motor technology selection, balancing efficiency and other requirements.