• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.844-849
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• 2008

In recent semiconductor manufacturing clean rooms, in order to improve clean room air quality, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from outdoor air introduced into clean room. Meanwhile, there is a large quantity of exhaust air from clean room. From the energy saving point of view, heat recovery is useful for the reduction of air conditioning energy consumption for clean room. Therefore it is desirable to recover heat from the exhaust air and use it to reheat the outdoor air. However, so far there have not been sufficient studies of analyzing the comparison of the amounts of energy consumption and saving. In the present study, an experiment was conducted to investigate the energy consumption and heat recovery of a fin-coil type air washer system for semiconductor manufacturing clean rooms.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.19-26
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• 2013

In this paper, we present a novel illumination system for parking lots constructed underground. We design and implement this system using microwave sensors and dimming control of LED fluorescent lamps so that we can obtain lighting efficiency of the illumination scheme. We construct an effective illumination system in the aspects of performance and cost, resulting in energy-saving and electricity reduction. Recently conventional energy-saving method applied to old underground parking lots mainly relies upon turning off the half of total number of lamps installed in the parking lot. Sometimes there are some lots that have infrared sensor to be used to turn on/off the fluorescent lamps to realize these operations smoothing. The other schemes utilize timer to control lighting time of the fluorescent lamps. These conventional schemes are forcing to turn off a part of lamps installed so that we cannot apply them in a systematic way. Moreover they will be most inefficient when we leave them alone to be continuous consumers. The lighting control system proposed in this paper can recognize objects through microwave sensors and inform the appropriate lighting time, furthermore we can adjust brightness of LED lamps following the surroundings using dimming control scheme so that we can epochally improve the illumination system for underground parking lots. According to our sophisticated test experiments, we can maximally obtain 81.9% of energy-saving effectiveness using the system proposed in this paper.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.38-44
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• 2011

In this study, heating performance and energy consumption characteristics with control strategies for central heating system were researched by the simulation. The simulation analysis is made by TRNSYS ver. 15 with the actual data. The parametric study on proportional factor, control time interval and outdoor air temperatures changes were done to compare control characteristics and energy performance, respectively. As a result, the simulation results with various parameter changes show good heating performance and energy saving.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1484-1487
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• 1996

An Automatic coking control system was developed to achieved substantial energy and labor savings through the stabilization and optimization of coke oven operation. With the aim of saving energy and labor, the coke department has been advanced automation and systematization. A typical examples of automation is Center Position Control System(CPCS) for coke oven. This system is proved effective in improvement of center position accuracy.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.502-507
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• 2009

Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on $115m^2$-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.2
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• pp.31-37
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• 2007

The fuzzy control algorithm for HVAC system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with fuzzy control are supply air temperature, chilled water temperature and condenser temperature. This study has been done by using TRNSYS program in order to analyze the HVAC system response. As a result, the fuzzy control algorithm with PID algorithm shows good energy performance in comparison with conventional one.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.4
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• pp.8-14
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• 2016

In this study, the effects of prediction and reset control of outdoor air temperature on energy consumption for central heating system are researched by using TRNSYS program package, and the control performances with the suggested methods of prediction and reset control of outdoor air temperature are compared with the existing ones. As a result, the value of coefficient of determination $R^2$ for the predicted outdoor temperatures is improved and the suggested control method shows maximum 21.8% energy saving in comparison with existing control ones.

• KIEAE Journal
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• v.10 no.6
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• pp.33-39
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• 2010

Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1211-1222
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• 2017

In order to decrease the parameter sensitivity of deadbeat direct torque control (DB-DTC), an improved deadbeat direct torque control method for surface mounted permanent-magnet synchronous motor (SPMSM) drives is proposed. First, the track errors of the stator flux and torque that are caused by model parameter mismatch are analyzed. Then a sliding mode observer is designed, which is able to predict the d-q axis currents of the next control period for one-step delay compensation, and to simultaneously estimate the model parameter disturbance. The estimated disturbance of this observer is used to estimate the stator resistance offline. Then the estimated resistance is required to update the designed sliding-mode observer, which can be used to estimate the inductance and permanent-magnetic flux linkage online. In addition, the flux and torque estimation of the next control period, which is unaffected by the model parameter disturbance, is achieved by using predictive d-q axis currents and estimated parameters. Hence, a low parameter sensitivity DB-DTC method is developed. Simulation and experimental results show the validity of the proposed direct control method.

• KIEAE Journal
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• v.14 no.4
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• pp.111-117
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• 2014

In South Korea, the government has recently enforced regulations associated with buildings. Temperature restriction in indoor environment is one of the common ways of energy reduction in order not to dissipate heating and cooling energy; however the people who are in restricted temperature feels uncomfortable. Furthermore, occupants cannot feel the same thermal sensation even they are in the same place. For the reason, occupants should express their thermal sensation and HVAC system should be able to apply their demand. It is proved by an adaptive principle. The adaptive model means that people react in ways which tend to restore their comfort, when change occurs such as to produce discomfort. In order to design HVAC control strategies based on adaptive model, we designated an existing office building as a reference building to gather data from actual field. Furthermore, we gathered occupants' thermal sensation and clothing insulation in real-time. We filtered the data with Kalman's filter method. The data was reasonable when there is an alarm messages for asking questionnaire. The response ratio were different in occupants' thermal condition. In conclusion, the filtered occupants' thermal sensation can be used as a real time HVAC control and input value of HVAC control.