• Journal of Power Electronics
• /
• v.13 no.2
• /
• pp.322-328
• /
• 2013

This paper presents a modified Current Source Parallel Resonant Push-pull Inverter (CSPRPI) for single phase induction heating applications. One of the most important problems associated with current source parallel resonant inverters is achieving ZVS in transient intervals. This paper shows that a CSPRPI with the integral cycle control method has dynamic ZVS. According to this method, it is the Phase Locked Loop (PLL) circuit that tracks the switching frequency. The advantages of this technique are a higher efficiency, a smaller package size and a low EMI in comparison with similar topologies. Additionally, the proposed modification results in a low THD of the ac-line current. It has been measured as less than %2. To show the validity of the proposed method, a laboratory prototype is implemented with an operating frequency of 80 kHz and an output power of 400 W. The experimental results confirm the validity of the proposed single phase induction heating system.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.40 no.1
• /
• pp.120-127
• /
• 1991

The purpose of this study is to develop a fault detection and diagnosis scheme that can monitor process fault and instrument fault of a steam generator. The suggested scheme consists of a Kalman filter and two bias estimators. Method of detecting process and instrument fault in a steam generator uses the mean test on the residual sequence of Kalman filter, designed for the unfailed system, to make a fault decision. Once a fault is detected, two bias estimators are driven to estimate the fault and to discriminate process fault and instrument fault. In case of process fault, the fault diagnosis of outlet temperature, feed-water heater and main steam control value is considered. In instrument fault, the fault diagnosis of steam genrator's three instruments is considered. Computer simulation tests show that on-line prompt fault detection and diagnosis can be performed very successfully.

• Journal of Navigation and Port Research
• /
• v.34 no.9
• /
• pp.705-709
• /
• 2010

Buildings nowadays are increasingly expected to need higher and more economic performance requirements. Energy consumption in buildings accounts for over 30% of total energy use. The Building Energy Management System (BEMS) and renewable energy (RE) technologies are considered as a potential measure to improve energy efficiency and reduce use of grid-power. It is, however, a challenge to utilise the intermittent energy supply of RE in building energy systems. This paper presents an experimental study on a RE-embedded BEMS. A control algorithm for the RE-embedded BEMS was designed to maximise the utilisation of RE and eventually to reduce electrical utility bill. The proposed system is tested at a laboratorial chamber with an air conditioner, fan and heater. The contribution of RE in building energy system is discussed to this end.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.975-983
• /
• 2013

This study proposes a low order dynamic model of a building system in order to predict thermal behavior within a building and its energy consumption. The building system includes a thermally well-insulated room and an electric heater. It is modeled by a second order lumped RC thermal network based on the thermal-electrical analogy. In order to identify unknown parameters of the model, an experimental procedure is firstly detailed. Then, the different linear parametric models (ARMA, ARX, ARMAX, BJ, and OE models) are recalled. The parameters of the parametric models are obtained by the least square approach. The obtained parameters are interpreted to the parameters of the physically based model in accordance with their relationship. Afterwards, the obtained models are implemented in Matlab/Simulink(R) and are evaluated by the mean of the sum of absolute error (MAE) and the mean of the sum of square error (MSE) with the variable of indoor temperature of the room. Quantities of electrical energy and converted thermal energy are also compared. This study will permit a further study on Model Predictive Control adapting to the proposed model in order to reduce energy consumption of the building.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.4
• /
• pp.395-401
• /
• 1999

In this paper, a temperature controller for a semiconductor test handler is proposed. First, a handware system for identification and control is established using RTD sensors, an A/D converter, solid state relays, a heater, and a computer system. Second, using ARMAX model and least square method, a chamber model for the design of a controller is identified through experiments. The identified model is verified to describe the real plant very well in the sense that it shows very similar input-output responses to those of the real system. With the identified model an LQG controller is designed. Frequency response of the designed controller shows that it has 15 dB of gainmargin and (-50˚, +50˚) of phase margin. Experiment with a real test handler demonstrates a good performance in the sense that its overshoot and steady state error are smaller and response time is faster, compared with those of a conventional PID controller.

• Proceedings of the KIEE Conference
• /
• 2003.10a
• /
• pp.45-48
• /
• 2003

In the research of proteomics, mass spectrometry analysis is the essential method for identification of the unknown proteins. Trypsin treatment for the sample preparation of mass spectrometry is the inevitable procedure[1]. However, sample preparation procedure is cumbersome and time consuming. To resolve these problems, Temperature controllable microreactor was designed and fabricated. It consists of metering chamber, micro channel, reaction chamber, platinum (Pt) thin film heater and a temperature sensor so that micro metering and mixture of reagent with temperature control can be done on the same chip. The total size of the fabricated microreactor was $37{\times}30{\times}1\;mm^3$ and the size of channel cross section was $200{\times}100{\mu}m^2$. PID temperature controller was realized using NI DAQ, PCI-MIO-l6E-1 board and LabVIEW program.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05a
• /
• pp.149-152
• /
• 2003

본 논문에서는 분산 실시간 서비스를 지원하는 TMO(Time-triggered Message-triggered Object) 객체를 기반으로 정보가전 기기들을 관리하기 위한 실시간 정보가전 제어 시뮬레이터를 설계 및 구현한다. TMO객체는 기존 객체를 확장한 실시간 특성을 자체적으로 가지는 객체를 UCI의 DREAM연구소에서 제안한 분산 실시간 객체이다. 이러한 TMO 객체를 기반으로 TMOSM(TMO Support Middelware) 상에서 실시간 정보가전 제어를 위한 TMO 객체들의 상호 동작과 실시간 속성을 설계하여 보장된 실시간 서비스를 지원하도록 한다. 본 시뮬레이션 모델은 온도제어, 조도제어, 방법제어 서비스를 지원하는 컴포넌트들로 구성된다. 온도제어 서비스를 위해 Fan_TMO와 Air_Conditioner_TMO, Heater_TMO가 상호 작용하여 적정 실내 온도를 유지하도록 하며, 조도제어 서비스를 위해 Light_TMO가 조도의 변화에 따라 동작하여 일상생활에 적당한 조명 환경을 제공한다. 또한 방범제어서비스를 위해 Camera_TMO가 정해진 시간을 주기적으로 동작하여 방범 활동을 수행한다. 그리고, 각각의 TMO 정보가전 객체들의 동작을 관리하고 서비스 수행 결과를 모니터링 하는 Home_Server_TMO가 존재한다. 마지막으로 설계된 시뮬레이션 환경을 구현하여 본 모델의 실시간 정보가전 제어 서비스를 정확하게 지원하는지를 검증한다. 제안한 시뮬레이션 환경은 일반 정보가전기기를 추가 작업 없이 실시간 서비스 지원 객체로 적용할 수 있는 모델이다.

• 한국전산유체공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.100-103
• /
• 2005

This work discusses the numerical analysis, the design and experimental test of the SMA (Shape Memory Alloy) actuator along with its capabilities and limitations. Convection heating and cooling using water actuate the SMA element of the actuator. The fuel such as propane, having a high energy density, is used as the energy source for the SMA actuator in order to increase power and energy density of the system, and thus in order to obviate the need for electrical power supplies such as batteries. The system is composed of a pump, valves, bellows, a heater (burner), control unit and a displacement amplification device. The actuation frequency is compared with the prediction obtained from numerical analysis. For the designed SMA actuator system, the results of numerical analysis were utilized in determining design parameters and operating conditions.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.6
• /
• pp.671-676
• /
• 1999

ITO (indium tin oxide) thin films on PET (polyethylene terephthalate) substrate have been deposited by a dc reactive magnetron sputtering without heat treatments such as substrate heater and post heat treatment. Each sputtering parameter during the sputtering deposition is an important factor for the high quality of ITO thin films deposited on polymeric substrate. Particularly, the material, electrical and optical properties of as-deposited ITO oxide films are dominated by the ratio of oxygen partial pressure. As the experimental results, the excellent ITO films are prepared on PET substrate at the operating conditions as follows : operating pressure of 5 mTorr, target-substrate distance of 45mm, do power of 20~30W, and oxygen gas ratio of 10%. The optical transmittance is above 80% at 550 nm, and the sheet resistance and resistivity of films are 24 Ω/square and $1.5\times$10$^{-3}$ Ωcm, respectively.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1364-1367
• /
• 2005

In this paper, a novel prototype topology of soft switching PWM controlled high frequency AC power conversion circuit without DC voltage smoothing chemical capacitor filter link from the voltage grid of utility frequency AC power supply source with 60Hz-100V or 60Hz-200V is proposed and introduced for innovative consumer induction heating(IH) boiler applications as hot water producer, steamer and super heated vapor steamer.