• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.924-926
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• 2003

단상 전원에 의해 기동 및 운전되는 영구 자석형 동기전동기는 일반 단상 유도전동기에 매우 높은 효율을 갖게 되지만, 회전방향을 정하기가 어렵다. 본 연구에서는 커패시터를 사용하는 커패시터 운전 유도 전동기와 같은 구조에 회전자를 영구자석을 사용하는 경우에 대하여 연구하였다. 즉, 회전자 조건에 따른 기동 조건을 계산하고, 이로부터 회전방향을 결정할 수 있어 고효율로 팬부하와 같은 기동토크가 작은 부하에 적용될 수 있을 것으로 기대된다.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.3-5
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• 2003

This paper deals with the characteristics of a capacitor-run single-phase induction motor by changing of conductor bar numbers. The Finite Element Method (FEM) is used to analyze the starting characteristics according to the rotor initial starting point about conduction bar and the characteristic analysis at the rated condition is calculated by equivalent circuit based on symmetry coordinate theory Finally, the analysis results of the analysis models have different conductor bars in their rotor are compared.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.910-912
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• 2001

The winding design of a capacitor-run single-phase induction motor for changing two poles(2-/4-pole) is proposed for reducing the harmonics of Magneto Motive Force(MMF) in the airgap at 2-role. To improve motor performance, it is important to analyze exactly the harmonics and design the winding pattern for its harmonics reduction. The winding design method to reduce the harmonics is suggested in this paper and its characteristics are analyzed by using equivalent circuit considering harmonic components. The various performances of the pole change motor with the proposed winding pattern are compared with the experimental results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.3
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• pp.173-181
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• 1989

A split-phase induction motor with asymmetrical magnetizing reactance axes develops starting torque and its efficiency can be high under certain conditions. In this paper, one method of producing the asymmetry of magnetizing reactance axes is described. The grain-oriented silicon steel core is used to produce the asymmetric axes instead of non-oriented silicon steel core which is used in general motors. The optimum design method for the motor is suggested and analyzed. To verify this suggestion, the permanent capacitor run type induction motors are designed to be driven at balanced condition by its asymmetrical effect, and then the oscillating torque due to the asymmetry of motor structures are analyzed. Tests of the sample motor have shown good performance comparable to ordinary types. This motor structure can be used where high effciency and reliability are required, and also the amount of core materials can be reduced due to its high permeability.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.945-947
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• 2003

Various kinds of practical machines using single phase induction motor(SPIM) are necessary to control speed and torque. In particular, capacitor-run type SPIM has constitutional characteristics, the motor torque is changed by auxiliary capacitance variation. In this study, we manifest equivalent model having more simplicity, and study the relation between torque and capacitance value of SPIM. And analyze Magnetic vibration for FEM(Finite Element Method) simulation. Also, We design the experimental controller which is able to speed control accurately by phase angle control of AC input voltage. Through the simulation and experimental results, we confirmed validity of this study.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.870-872
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• 2003

This paper deals with the characteristic analysis of capacitor-run single phase induction motor by equivalent circuit. The unbalanced elliptic rotating magnetic field of the motor was analysed by the symmetrical coordinate method. And this paper check the reliability of characteristic analysis by equivalent circuit in comparison with experimental results and analyse the characteristics of single phase induction motors by changing circuit parameters. Finally, this paper shows the improved effiency design motor by using that result.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.391-396
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• 2009

In this paper, a control algorithm for DC-Link voltage unbalancing compensation of a four-switch inverter for a three-phase BLDC motor drive is proposed. Compared with a conventional six-switch inverter, the split source of the four-switch inverter can be obtained by splitting DC-link capacitor into two capacitors to drive the three phase BLDC motor. The voltages across each of two capacitors are not always equal in steady state because of the unbalance in the impedance of the DC-link capacitors $C_1$ and $C_2$ or the variable current flowed into the capacitor's neutral point in motor control. Despite the unbalance, if the BLDC motor may be run for a long time the voltage across one of the capacitors is more increased. So the unbalance in the capacitors voltages will be accelerated. As a result, The current ripple and torque ripple is increased due to the fluctuation of input current which flows into 3-phase BLDC motor. According to that, the vibration of motor will be increased and the whole system will be instable. This paper presents a control algorithm for DC-Link voltage unbalancing compensation. The sampling from the voltages across each of two capacitors is used to perform the voltage control of DC-Link by using the feedforward controller.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.479-483
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• 1997

In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.792-797
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• 2010

Microwave oven and household cooker are devices of high voltage producer and high voltage storage batteries respectively for formation of necessary high frequencies at drive. These devices emit much heat energy because they are run at high voltages. Therefore, emitted heat energy becomes a factor that raises temperature of microwave ovens' main frame. In this research, the analysis shows the temperature distribution in microwave oven with the cooling fan drive conditions and the heat energy occurrence conditions. According to the analysis, as the speed of air outpoured in cooling fan increases, and the internal temperature decreases quantitatively. Also the inside temperature distribution was investigated by controlling heat energy emission.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.54-59
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• 2005

Brushless DC motor is a motor which is modified form DC brush motor and it does not have brushes. BLDCM is easy to centre, has wide speed range, high efficiency. However it needs speed sensor like encoder which increases the motor price and cause some faults in poor surroundings.. In this paper, for the sensorless control, the driving techniques for the initial stable start and the steady state are studied For the steady state the rotor position is determined using the measured back-EMF. To enhance the initial stating performance, the current signal from the free-wheeling diode is used. The results are conformed through the experiments.