• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.1
• /
• pp.27-33
• /
• 2005

The development of modern high-energy magnet materials has allowed the replacement of field coils in many different types of electromagnetic energy conversion machines. As well, the linear synchronous motor has recently been proposed for linear motion with high efficiency and thrust. Thus, this paper presents an analytical solution for the high thrust and cost reduction of the Iron-Cored Permanent Magnet Linear Synchronous Motor (PMLSM) considering magnetization arrays and geometry. Hence, the superior utilization points in each of the magnetization arrays are provided by the height ratio of the magnet/air-gap and magnet/winding coil, etc. In formulation, the space harmonic method in analytical solutions and the generalized 2-D tensor finite element analysis can be used to evaluate force components in magneto static devices including the magnetostrictive phenomenon.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.138-141
• /
• 2002

BLDCM(Brushless D.C. Motor) is widely used for industrial application because of high efficiency and high power density Especially, in servo system and home appliance, BLBCM is very useful due to high control performance and low acoustic noise. In this paper, 2.5HP rated BLDCM controller and drive was developed for tread mill application. The prototype BLDCM has 4 poles rotor and 24 slots stator. Ferrite was used as a rotor magnet due to the cost and temperature characteristic. For the stable operation of tread mill, over current and high temperature can be detected by the DSP controller. For the commutation signal, switching patterns from the sensorless circuit and hall sensor signal are used in the DSP controller.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1019-1021
• /
• 2004

BLDCM(Brushless D.C. Motor) is widely used for industrial application because of high efficiency and high power density. Especially, in servo system and home appliance. BLDCM is very useful due to high control performance and low acoustic noise. In this paper, 2.5HP rated BLDCM controller and drive was developed for tread mill application. The prototype BLDCM has 4 poles rotor and 24 slots stator. Ferrite was used as a rotor magnet due to the cost and temperature characteristic. For the stable operation of tread mill. over current and high temperature can be detected by the DSP controller. For the commutation signal, switching patterns from the sensorless circuit and hall sensor signal are used in the DSP controller.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.55 no.4
• /
• pp.139-143
• /
• 2006

Recently, standard of living improved and Information-Communication industry developed rapidly. Thereby, interest about electric power quality is rising worldwide. So, research and Development to enhance electric power quality in various viewpoint until most suitable supply system from each kind device to improve electric power quality. And specially, interest about voltage quality is rising by diffusion increase of information communication appliance and minuteness control appliance etc. Also Power consumption is increasing, but expansion of large size generator by environmental and site security problem is difficult. So, introduction of distribution generation is investigated actively by electric-power industry reorganization. Voltage management of power system had been controlled by ULTC (Under Load Tap Changer) in substation and pole transformer on the high voltage distribution line. But, voltage control device on substation and distribution line is applied each other separatively. Therefore, efficiency of line voltage control equipment is dropping. Also, research about introduction upper limit of distribution generation is consisting continuously. This paper presents cooperation use way between voltage control device and introduction upper limit of distribution generation for most suitable voltage control in distribution power system.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.4
• /
• pp.312-316
• /
• 2005

The single phase induction motor has been commonly applied to small-sized electrical appliances because of its low cost, but it has low efficiency and large torque ripple, and it is incapable of speed control. However, two-phase induction motors have small torque ripple, high efficiency and variable speed control, because they are inverter fed. In this paper, the dynamic characteristics of the two-phase induction motor, such as the torque ripple, current and speed, are analyzed by using the time-stepping finite element method, and compared with the cage-type single phase induction motor.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.50-53
• /
• 2004

BLDCM(Brushless D.C. Motor) is widely used for industrial application because of high efficiency and high power density. Especially, in servo system and home appliance, BLDCM is very useful due to high control performance and low acoustic noise. In this paper, 2.5HP rated BLDCM and its controller is developed for tread mill application. The prototype BLDCM has 4 poles rotor and 24 slots stator. Ferrite magnet was used as a rotor magnet because of the cost and temperature characteristic. For the stable operation of tread mill, current and temperature can be detected and treated by DSP. Thedesigned BLDCM and its controller is verified by the experimental results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.2
• /
• pp.96-105
• /
• 2001

R410a which is one of HFC refrigerants is being considered to be a promising replacement for R22 widely used in domestic air conditioners. The rolling piston type rotary compressors for R410a have lower energy efficiency than those for R22 because of the high pressure difference between a suction chamber and a discharge chamber in the compression mechanism. in addition, the re-expansion gas loss of the rotary compressor for R410a which occurs a ta clearance volume in a discharge port becomes larger than that for R22 due to high density of R410a refrigerant. Therefore, Pressure-Volume analyses for various design parameters of a discharge system were carried out to improve efficiency of a R410a rotary compressor. The results such as performance dta, over-compression loss, and re-expansion loss were acquired by P-V analyses and analyzed quantitatively. As a conclusion, the optimal specifications of several design parameters of a discharge system were obtained by analyzing P-V diagrams.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.15 no.8
• /
• pp.619-629
• /
• 2003

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. Since the inertial impaction is a dominant particle removal mechanism of the grease filter, the performance of the filter is greatly affected by the geometry. This numerical study has been conducted to investigate the effect of geometry on the performance of grease filters for four models having nominal flowrate of 100 m$^3$/h. Four models were designed by changing the shape of impaction surface, the length of eyelid, and the number of eyelids of the grease filter. The flow field and particle trajectories in the grease filter with a flow chamber were simulated using the commercial code of STAR-CD. The difference of air velocity and pressure distributions among four models was discussed in detail. The collection efficiency curves and the pressure drops of four models were also compared. It was found that the grease filter model with flat top surfaces shows highest performance among four models, having high particle collection efficiency and relatively low pressure drop. The cutoff diameter of this model representing 50-% collection efficiency is about 7.1 ${\mu}{\textrm}{m}$ for water droplets at 100 m$^3$/h.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.848-850
• /
• 2002

Single phase induction motor is directly used usual source, it can be a source of an appliance such as mechanical fan, refrigerator, washing machine, etc. Especially capacitor-run single phase induction motor is suitable to make more inexpensive and high efficient products because it is more high efficiency, and good to start than other single phase induction motors. Generally, voltage and current of capacitor-run single phase induction motor transfer to the part of positive phase and negative phase based on two motor theory. In this paper, we simulate the torque characteristics to capacitance variation from single phase induction motor's equivalent circuit. Through the test using the real motor, we compare and investigate the maximum torque of run state related with capacitance and the adequacy of the converted model.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.107-109
• /
• 2003

Single phase induction motor is directly used usual source, it can be a source of an appliance such as mechanical fan, refrigerator, washing machine, etc. Especially capacitor-run single phase induction motor is suitable to make more inexpensive and high efficient products because it is more high efficiency, and good to start than other single phase induction motors. Generally, voltage and current of capacitor-run single phase induction motor transfer to the part of positive phase and negative phase based on two motor theory. In this paper, we simulate the torque characteristics to capacitance variation from single phase induction motor's equivalent circuit. Through the test using the real motor, we compare and investigate the maximum torque of run state related with capacitance and the adequacy of the converted model.