• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.421-427
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• 2005

A closed-loop sensorless stroke control system for a linear compressor has been designed. The motor parameters are identified as a function of the piston position and the motor current. They are stored in ROM table and used later for the accurate estimation of piston position. Also it was attempted to approximate the identified motor parameters to the 2nd-order surface functions. Some experimental results are given in order to show the feasibility of the proposed control schemes for linear compressors.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.173-179
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• 2014

In this paper, a motor parameter identification system has been implemented to improve the performance of the position sensorless stroke controller for linear compressors. In order to control the cooling capability of a refrigerator or an air conditioner in which linear compressors are applied, the piston speed should be controlled. The piston speed control can be obtained by adjusting the frequency or the stroke of linear motors. The dynamic performance of linear compressors depends on how accurately the stroke or the piston amplitude is estimated. The merits and demerits of Constant method and PIM (Parameter Identification Method) concerning the needed memory space and the stroke error are discussed and verified via some experimental studies.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.156-163
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• 2014

In this paper, a phase control system has been implemented to improve the dynamic performance of the stroke response for linear compressors. In order to control the cooling capability of a refrigerator or an air conditioner in which liner compressors are applied, the piston speed should be controlled. The piston speed control can be obtained by adjusting the frequency or the stroke of linear motors. The dynamic performance of linear compressors depends on how accurately the stroke or the piston amplitude is estimated. A phase control system is added to the stroke control loop and the superior performance of the phase control system is verified via some simulation studies.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.10-15
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• 2016

This paper is to analyze and study the failure examples of refrigerant gas in automotive air conditioner. The first example, the air conditioner compressor continually operated that the refrigerant was leaked in air conditioner system. By lubrication shortage, the piston was partially sticked on cylinder of air conditioner compressor inner part. This was caused the phenomenon of engine operation trouble by load increasing with engine rpm variation during engine running. The second example, it sought the fact that the air conditioner refrigerant gas was leaked from air conditioner compressor to condenser high pressure pipe toward rear air conditioner checking with the lines of air conditioner. The third example, the refrigerant gas of air conditioner found that was leaked imperceptible from condenser inner by crack that was generated on the fins of air conditioner condenser. Therefore, the air conditioner system that maintain the air conditioner by decreasing the in-car temperature must meticulously manage to not leak the air conditioner refrigerant gas.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.53-59
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• 2000

In this study aluminum casting experiments are carried out to reduce the grain size of a cast preform and to spheriodize its dendritic structure by adding Ti+B and Zr and to modify flaked eutectic silicon by adding Sr, And a finite element simulation is performed to determine an optimal configuration of the cast preform to be used in forging of a compressor piston for an automobile air-conditioner. When 0.15% Ti+B Zr and 0.05% Sr are added respectively into the molten aluminum alloy the finest grain in casting of the preform is obtained. It is confirmed that the optimal configuration of the cast preform predicted by FEM simulation is very useful for forging the compressor piston. After forging the cast preform of the compressor piston. the microstructure and the hardness of the cast preform is compared with those of the cast/forged product.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.212-218
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• 2013

In this paper, a linear motor piston amplitude estimator using phase lag filter has been implemented. In order to control the cooling capability of a refrigerator or an air conditioner in which liner compressors are applied, the piston speed should be controlled. The piston speed control can be obtained by adjusting the frequency or the stroke of linear motors. The dynamic performance of linear compressors depends on how accurately the stroke or the piston amplitude is estimated. A linear motor piston amplitude estimator using phase lag filter is proposed and the superior performance of our estimator is verified via some simulation studies.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.385-390
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• 2012

This paper discusses the applicability of a compact rolling piston refrigeration compressor to portable refrigerators. The capacity of this compressor is 1 cc. Using a 12 V BLDC motor, the compressor is driven from 2500 rpm to 6000 rpm. The height of the compression module and motor is approximately 56 mm, and their weight is approximately 374 g. We confirmed the effective operation of the compressor components by evaluating their compression and cooling performance.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.61-68
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• 2012

In this paper, a closed-loop sensorless stroke control system for a linear compressor has been designed. In order to estimate the piston position accurately, motor parameters are identified as a function of the piston position and the motor current. These parameters are stored in ROM table and used later for the accurate estimation of piston position. The identified motor parameters are approximated to the several surface functions in order to decrease memory size. They can also be divided into 2 or 4 subsections to decrease identification errors. The effect of the order of surface functions and division of subsections on identification errors and computation time is analyzed.