• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.46-46
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• 2004

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.424-429
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• 2003

A reciprocating compressor with a rotary motor used in a refrigerator has low efficiency, because it has the large mechanical losses due to the crank mechanism. The linear compressor which has the free piston driven by a linear motor, was developed to increase the efficiency of compressor by reducing mechanical losses. The TRIAC has been widely used for controlling the piston, because it has simple structure. However, as it is able to control only stator voltage, it is very difficult to obtain good efficiency. Recently, PWM inverter which is able to control the voltage as well as the frequency, is applied to linear compressor drive system to overcome above problem. In this paper, the variations for efficiency and power factor of linear compressor are investigated by changing both the mechanical resonant frequency and electrical resonant frequency of linear compressor, and also the inverter frequency The optimum relationships between both resonant frequencies and the inverter frequency is derived in order to obtain the maximum efficiency and also good power factor.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.6
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• pp.517-523
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• 2016

Unlike household refrigerators, commercial refrigerators are composed of separate indoor and outdoor units. The outdoor unit of most commercial refrigerators is designed to run at a fixed speed, which results in low energy efficiency and loud fan noise. Moreover, it cannot respond flexibly to changing thermal load in the indoor unit. Inverter type outdoor units can address such problems through speed changes based on information obtained from the indoor unit. However, using two units from different manufacturers is often not a viable solution. If condition changes in the indoor unit can be detected without communication between the two units, it is possible to adjust the speed of the outdoor unit. This paper attempts to analyze the signal from the outdoor unit when the condition of the indoor unit changes by varying the thermal load.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.200-207
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• 2000

Recently, it is increased to apply the inverter system to household electrical appliances, especially in the air c conditioners, refrigerators and washing machines, to reduce the power consumption and the acoustic noise by t the low speed operation, and to make their functions more comfortable for human beings. For the inverter s systems, however, it is highly required to reduce the undesirable electromagnetic noise and psychoacoustic n noise generated by PWM for variable speed operation. In this paper, the electromagnetic noise for the d detenninistic PWM and random PWM for the reciprocating compressors driven by the brusWess dc motor was a analyzed. It was also verified through the experiment that the elt'Ct$\tau$omagnetic noise was reduced and the s sound quality was improved by applying the random PWM.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.274-282
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• 2013

In this paper, a linear motor stroke controller using a phase lag filter and a single phase PWM inverter with a current controller has been implemented. 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. Generally, the frequency is fixed, for example, as 60Hz and the stroke is adjusted. The dynamic performance of linear compressors depends on how accurately the stroke or the piston position is controlled by the current applied. A linear motor piston position controller with a current control loop is proposed and verified via some simulation studies.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.210-211
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• 2013

냉동차량은 이동 또는 정차 중에도 냉동 부하에 일정 온도를 유지 시켜야한다. 종전의 상용차량에 냉동시스템은 차량의 엔진과 연계하여 압축기를 구동하거나 엔진과 연계된 발전기의 전력을 이용하여 일정 온도를 유지하였다. 이러한 방식은 제어가 쉽지 않고 효율이 낮은 단점을 가지고 있다. 본 논문에서는 이러한 단점을 개선하고자 냉동차량이 정차 중인 무시동 기관에서도 일정 온도를 유지 할 수 있도록 센서리스 제어방식이 적용된 3상 인버터를 제안하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.788-793
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• 2014

In this study, the electrical power consumption saving effect is studied through installing an inverter which is able to control the R.P.M. of marine sea water pump by effective flow control. The study looks at how sea water pump's flow control influences on the system without the Marine Growths Protection System(MGPS). Auxiliary sea water pump and refrigerator sea water pump in training ships, which are always operated not only in harbor but also in navigation, was used in the experiment and the experiment was conducted by dividing into harbor and navigation. As a result of research, in the case the sea water temperature is under $18^{\circ}C$, the operation was possible with a 58.3 % decrease in pump R.P.M. and electric power consumption was saved by 50 %. In spite of the sea water temperature increasing upto $34^{\circ}C$, pump R.P.M. at 91.6 % was sufficient to operate with a 20 % electric power consumption saving effect. In the pipelines without MGPS, lowering R.P.M. along with lowering pressure results in the attachment of various marine growths.