• 동력기계공학회지
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• 제12권4호
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• pp.32-38
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• 2008

The improvement of cooling ability for the air conditioner is the most efficient method of application of its system. Therefore, this study has been investigated the improvement of cooling ability for the air conditioner using automotive by attached of a thermoelectric module. According to the result of test, capacity of the thermoelectric module make temperature range from $-75^{\circ}C$ to $+300^{\circ}C$ possible to cooling and exothermic. In addtion to, the reduction effect of energy revealed and the effect of liquid hammer remained with safety by attached the thermoelectric module. It was found that the air conditioner system by attached thermoelectric module have better cooling ability than the air conditioner system of existing vehicle.

• 태양에너지
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• 제18권3호
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• pp.129-135
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• 1998

A photovoltaic system is an infinite and clean energy system. A photovoltaic system consists of a solar cell array, a converter, a inverter and a control unit. It is necessary that the Maximum Power Point Tracker(MPPT) is applied to the photovoltaic system because the output power of solar cell array is varied with irradiation, temperature and external effects. In this paper, the neural networks theory, one of the control methods, is applied to track the maximum power point of the photovoltaic system. The MPPT using neural networks theory is proposed to improve existing energy converter efficiency. Also the theory is applied to operation of inverter type airconditionig system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.551-556
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• 2008

This study analyzed operation characteristics of air-condition piping is made by quick disconnect coupling. Air-conditioning consists of central compressor 3HP capacity and R22 refrigerant. We experimented with two operation cycles of air-condition under the same environment; one is with quick disconnect coupling. The other is without quick disconnect coupling. As a result, we can observe whether the condensation temperature of former increased by about 3-5. Furthermore, COP decreased by about 10%.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.241-244
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• 2001

This paper proposes a nonlinear impedance circuit composed by diodes and inductors or capacitors. This circuit needs no control circuits and switches, and the impedance value is changed by the polarity of current or voltage, This paper presents one of these applications to improve the input current of capacitor input diode rectifiers. The rectifier using the nonlinear impedance circuit id constructed with four diodes and four capacitors in addition to the conventional rectifiers, that is it has eight diodes and five capacitors, including a DC link capacitor. It makes harmonic components of the input current reduce and the power factor improve. A circuit design method is shown by experimentation and confirmed simulation. It explained that compared conventional pulse-width modulated (PWM)inverter with half pulse-width modulated (HPWM) inverter. Proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.345-351
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• 2000

To improve the current waveform of diode rectifiers, we propose a new operating principle of the voltage diode rectifiers. In the conventional voltage rectifier circuit, relatively large capacitors are used to boost the output voltage, while the proposed circuit uses ones and a small reactor not boost the output voltage but improve the input current waveform. A circuit design method is shown and confirmed simulation. It explained that compared conventional PWM(Pulse-width modulated)inverter with HPWM(Half Pulse-width modulated)inverter. Proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting. Output voltage and current of this paper were applied for real air-conditioner.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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• pp.6-8
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• 2002

Generally in solar air conditioning system, the diode rectifier is used to build up DC link voltage from AC source. The diode rectifier is simple and cheap but it brings out the problems of low power factor and plentiful harmonics at the AC source. Also It can degrade the utilization rate of solar energy because the reverse of power flow cannot be made. Hence, in this paper to overcome the peak power problems in summer and to endure good AC input characteristics, solar air conditioning system using the PWM converter is proposed. A high input power factor of 97[%] and an efficiency of 98[%] are also obtained. The harmonic guide lines of proposed rectifier is no interfered with inverter switching, resulting in a simple, reliable and low cost ac to dc converters in comparison with the boost type current improving circuits.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3051-3053
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• 1999

In recent years, it becomes a worldwide trend that the power utilities focus their attention to Demand Side Management. Increasing Electric power consumption, they adopt a direct load management to accomplish low cost and stability of electric supply. Following this trend, KEPCO is researching a Direct Load Control System for Air Conditioner. This Paper presents the development results of the Direct Load Control System to Control electric power consumption of Conditioner in summer period this year.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2358-2361
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• 2003

In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.662-665
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• 2005

In this study acoustical characteristics of system air conditioner in different ceiling systems was investigated in anechoic and real conditions. Same Types of air conditioners were installed in two different rooms. The results showed that motor's tonal component was emphasized at near fart of air blast blower in the exposed type while fan's harmonic component is emphasized rather in the enclosed type. This confirms tile result of acoustical intensity mapping which showed that Intensity level of 125Hz octave band increased in the exposed type while there was no noticeable difference at the frequency band in the enclosed type.

• 대한임베디드공학회논문지
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• 제19권3호
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• pp.123-130
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• 2024

This paper proposes an EMPC (Explicit Model Predictive Controller) for temperature tracking control based on heat load prediction by an ESO (Extended State Observer) for a variable cooling circulation system with multiple indoor units connected to one outdoor unit. In this system, heat transfer and heat loss relative to the input temperature are modeled using system dynamics. Using this model, we design an EMPC based on an ESO that is robust to temperature changes and depends on airflow. To determine the stability of both the controller and the observer, asymptotic stability is verified through Lyapunov stability analysis. Finally, to validate the performance of the proposed controller, simulations are conducted under three scenarios with varying airflow, set temperature, and heat load.