• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.802-804
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• 2002

An analysis of the skeleton type BLDC motor is presented. The single phase skeleton type BLDC motor consists of the stator, rotor with the permanent magnet, and drive circuit with hall sensors that detect the rotor position. The major factors for the initial starting, efficiency, and torque ripples of the skeleton type BLDC motor are the detent groove of the stator and the lead angle of the phase voltage. The performance characteristics according to the angle and height of the detent groove is analyzed. The optimum lead angles of the phase voltage with the torque ripple and motor efficiency is described using the finite element method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.10
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• pp.470-476
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• 2005

In this paper PU control scheme is presented. The proposed scheme has following features. The one is oft-starting method which is used for preventing to flow large current in motor phase winding when motor starts. The ther is the selection of the level of the over current. The first feature is implemented by increasing the PWM duty lowly, the second feature is implemented by limiting the magnitude of the phase current level by which the over heat f motor by copper losses and magnetic saturation decreases. By the analysis using FEM considering load condition, the peed of mode transition from PW to single pulse control is selected and confirmed by simulation that there is no ver current occurs during the mode transition. For the verification of proposed scheme, the simulation using MATLAB Simulink with considering non-linearity of inductance profile from FEM analysis is performed and the experiment with SRM drive system which has the DSP controller and single Phase SRM are peformed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.418-422
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• 2001

This paper presents a developed squired cage induction motor for axial flow fan. The developed squirrel cage induction noter for axial flow fan is exchanged the position, rotor and stater. In this method a fan blade is attached to outside rotor. So we can protect the motor from rain and reduce noise, and there is no need to have bending duct to locate the fan motor. Carried out experimental test with this induction motor, and the results were as follows. Starting torque was 21kgㆍcm@120V, maximum efficiency was 0.84@120V. The characteristics of tests were the same as double squirrel-cage type IM.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.1
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• pp.41-45
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• 2008

This paper describes a simple and straightforward method to determine phase converter reactances for the monocyclic start induction motor which have two different phase converters. In order to determine two reactances, two kinds of simultaneous equations with two unknown reactances at a specified speed are set up by the condition of balance operation. From these equation, these unknown reactances can be solved directly using the application software without any algebraic calculation. The applicability of this method is investigated by comparing with the known method by using the computed results at the starting and rated speed, and the results show good agreement each other. Using these results, the performance characteristics of this motor are computed and compared with three phase balance operation of induction motor.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.861-865
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• 1998

A plate-type linear ultrasonic motor using logitudinal and bending multi-vibration mode was designed and fabricated for the application to card-forwarding device. The stator consisted of PZ-PT-PMS piezoelectric ceramic plate and stainless steel. The performances of the motor were measured. As the experimental results, no-load speed of the motor was 0.6m/s when applied voltage was $80\textrm{V}_{rms}$ in resonance frequency. Starting torque was 1.4 mNm and maximum efficiency was 1.2%.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.972-974
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• 2000

In this paper, we describe the starting and synchronizing methods in the linear induction synchronous motor. The proposed motor consists of one pair of linear synchronous motors (LSMs) and an additional linear induction motor (LIM). The primary cores have a common ring winding, and solid conductors are arranged in both LIM and LSM. From the investigation by analysis and experiment, we verify that the proposed motor is effective for practical use.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.50-55
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• 1999

Brushless DC Motor(BLDCM) has high efficiency. But this type of motor needs a rotor sensor which complicates the motor configuration. Rotor position sensor degrades system reliability in the severe environmental condition. In this paper, we study a controller which permits the determination of the rotor position by the back EMF to eliminate the rotor position sensor Also, since the back EMF is zero at standstill, a starting technique which permits the starting of an asynchronous motor without a sensor is described. The controller is implemented using microcontroller for minimal external component.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.247-251
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• 2001

Universal motors are mainly used for vacuum cleaner application. There are a lot of researches on SRM that applys home appliance throughout the world. The manufacturing cost of SRM drive makes it hard to expand its application to home appliance. This paper presents Single Phase SRM for the vacuum cleaner that has advantge in cost and performance over conventional universal motor. This paper proposes new power device driving scheme by using SRM switching characteristic. The driving scheme is very simple and inexpensive. Dwell Time Control method is used for the minimum switching loss of power device. The switching frequency of power device is less than 4.5kHz at 45,000rpm. By use of this scheme, power device based on very small switching losses can be used on SRM drive. Also, the biggest problem in single phase SRM is starting, this paper shows a new starting algorithm with two hall sensors, accelerating and running sensors, respectively. Finally, the proposed Single Phase SRM achieves higher efficiency and long life time compared to universal motor. Its life time is more than 1500 hours. Its life time is extended 4 times than that of conventional motor and its suction power is increased $20\%$ at the same volume of conventional universal motor.

• Journal of Power System Engineering
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• v.6 no.3
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• pp.36-41
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• 2002

A swashplate type piston motor with a tripod joints is introduced to improve compactness and starting torque in conventional types of motor. If the driving torque of motor shaft is transmitted by utilizing the mechanism, its friction torque loss would be drastically reduced and mechanical efficiency would be improved because the lateral force on the piston of the rod type motor with tripod joints mechanism is relatively smaller than that of the conventional plunger type motor. In particular, kinematics analysis for the mechanism are done as a preliminary study to investigate the feasibility of the mechanism in the axial piston motor. General formulas are derived from the displacement and velocity analysis of the mechanism, showing relationships between output shaft and shoe holder motion. A series of numerical calculations are carried out for a medium size motor with 160cc/rev using the formulas and their graphical plots are shown as well.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.8
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• pp.370-376
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• 2005

The single-phase induction motor is simple and durable, but the efficiency is low. Therefore, electric motors like HLDC and LSPM(line-start permanent magnet motor) that use the permanent magnet have been studied. The most advantages of single-phase LSPM is having the same stator as the stator of the single-phase induction motor and permanent magnets are just inserted in the squirrel cage rotor of the single-phase induction motor. But the characteristics of single-phase LSPM synchronous motor has very complex characteristics until the synchronization and if the design is not suitable, the single-phase LSPM synchronous motor cannot be synchronized. We designed a single-phase LSPM using the same stator and winding as the conventional single-phase induction motor, but newly designed the permanent magnets considering air gap magnetic flux density. The transient characteristics of the single-phase LSPM is not good because of a magnetic breaking torque, however, it can be improved by redesigning the rotor bars. We are proposed the design method of rotor bar for the single-phase LSPM to start softly and to make synchronization easily.