• Journal of the Korean Society of Industry Convergence
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• v.23 no.3
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• pp.499-505
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• 2020

Capacitor-run single-phase induction motor is cheaper than motors that use permanent magnets and is widely used in home appliances and industries based on relatively high durability and productivity. It can also be operated by line. However speed cannot be controlled because the line frequency is free. In this paper we dealt pole change method one of the method controlling speed of capacitor-run single-phase induction motor. The conventional pole change method is difficult to improve the power and efficiency of the motor because the composition of the pole change device is complex and do not have enough area of the windings because of windings not used according to the driving conditions. In this paper, we proposed the pole change method that is used main windings and auxiliary windings at 4 poles operation and used auxiliary windings as compensation windings at 2 poles operation. The proposed method was verified through finite element analysis.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.162-167
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• 2005

This paper deals with the method of characteristic analysis of the capacitor-run single- phase induction motor having two poles (4-pole and 2-pole). This motor, which is referred to as a pole change motor in this paper, is capable of variable speed operation without inverters or drives. However, speed-torque curve can be distorted by the harmonic components contained in the magnetic flux density distribution. Therefore, the characteristics of this motor are analyzed using equivalent circuit considering harmonic components and the simulation results are compared with the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.194-199
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• 1989

In this paper, using the direct drive arm for plant, the controller is developed to track the desired trajectory in high speed and precision. For the purpose of this, through extending self-tuning pole-placement algorithm, we developed self-tuning pole-shift algorithm which is fast in response and good tracking for the reference tracking change. Developed controller is applied a three-link direct drive arm with the varing payload to track the desired tracking. And, through the computer simulation, the performance of developed controller is compared with the performance of the computed torque method and the self-tuning pole placement algorith.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.907-909
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• 2001

This paper proposes the analysis method for the pole change motor that is a capacitor-run single-phase induction motor. As the Magneto motive force(MMF) at 2-role becomes severe distortion, it is necessary to consider the harmonics for the characteristic analysis of the motor. Therefore, the performance of motor is analyzed by equivalent circuit considering the harmonic components. The validity of the proposed analysis method for the pole change motor is verified through simulations and experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.108-113
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• 2013

Change of supply voltage, customer load, output of distributed generation, etc cause voltage change in distribution system. OLTC and SVR are usually used to supply normal voltage at customer. But usage of these devices is inefficient and uneconomical in certain circumstances. To solve this problem, new pole transformer which has automatic tap changer is developed. The transformer changes tap when voltage changes. And it has latch switch and reactor for supplying power without outage. To verify normal operation of tap changer, test is conducted. SVR and 50kVA load is used for test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.321-326
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• 2013

This paper investigates the magnetic excitation force of a surface-mounted permanent magnet (SPM) motor according to the change of pole/slot combination. The characteristics of magnetic flux and radial magnetic force (RMF) due to pole/slot combination were analyzed by using magnetic circuit analysis. Also, the RMF of motors with the variable pole/slot combination was numerically simulated by using the finite element analysis to verify the result of the magnetic circuit analysis. This research shows that RMF ripple is reduced when the number of pole is smaller than the number of slot.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.4
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• pp.7-13
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• 2005

In the case of fabricating micro pole structures such as column, square-pole and gear shaft by the micro end-milling process, it can be useful in the fields of industry, for example, micro parts, electrode for electrical discharge machining and micro mold for injection molding. In this study, machining factors and the process were analyzed. Machining experiments of various micro pole configurations were performed. Analysis of the change and effect of the cutting force according to the machining conditions was carried out. An analytical study of the deformation of the micro pole caused cutting conditions and cutting force through the finite element method and ANSYS program was carried out. As a result, this research presented a method of fabricating the column pole of below $100{\mu}m$ diameter with high aspect ratio by using micro end-milling process, and based on that, a method of fabricating a variety of applicable structures. Also the minimum size of the pole capable of fabricating through theory and experiment were demonstrated.

• Human Ecology Research
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• v.58 no.1
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• pp.87-103
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• 2020

This study discusses the institutional change of Chinese early childhood education quality assurance institution (ECEQAI) from the three dimensions of the perspective of historical institutionalism of that refer to the external environment, dynamic mechanism containing with nation-market-society, and the invisible ideology of the institutional change. Chinese ECEQAI was divided into five historical periods, which were 17 years after the founding of China (1949-1966), the Great Cultural Revolution (GCR) period (1966-1976), the early stage of Reform and Opening-up (RO) (1976-1995), the social change period (1995-2010) and the new period (2010-now). This study also concludes five separate change models for Chinese ECEQAI that correspond to the five periods. The first was a compulsory and gradual institutional change model influenced by the Soviet model and dominated by national power. The second was compulsory and radical change model controlled by the counter-revolutionary group. The third was a compulsory and gradual institutional change model dominated by national power. The fourth was induced and gradual^① institutional change model driven by market power and forced by society power. The fifth was a compulsory and gradual institutional change model led by national power and forced by society power. Finally, the future change direction of China's ECEQAI was further pointed out, that was the government-leading and tend to balanced three-pole power model of "Nation-Market-Society", as well as the "three-pole power relationship" of indepth communication and positive interaction.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.643-651
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• 2006

The theory for a novel fault-tolerant 4-active-pole homopolar magnetic bearing is developed. If any one coil of the four coils in the bearing actuator fail, the remaining three coil currents change via an optimal distribution matrix such that the same opposing pole, C-core type, control fluxes as those of the un-failed bearing are produced. The hompolar magnetic bearing thus provides unaltered magnetic forces without any loss of the bearing load capacity even if any one coil suddenly fails. Numerical examples are provided to illustrate the novel fault-tolerant, 4-active pole homopolar magnetic bearings.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.452-456
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• 1988

A PID controller must need not only good servo response but also little operation of a control valve. We suggest a direct pole-placement PID self-tuning algorithm using the structure of derivative-of-output controller and Bezout identity. This algorithm can much reduce the change of output of controller and well follow the desired trajectory.