• Journal of Drive and Control
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• v.12 no.1
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• pp.45-52
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• 2015

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.319-328
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• 2009

IEEE 802.16e standard defines different Sleep Mode Operations according to kind of services which aims at saving energy for MS efficiently. The previous study of Sleep Mode Operation is limited for single service environment, real sleep interval is decreased because different Sleep Mode Operations are applied at once when MS is on multi service. The proposed Enhanced Sleep Mode Operation increasing real sleep interval of this paper guarantees QoS(Quality of Services) which is same as standard, minimizes energy consumption when different Sleep Mode Operations are applied at once. Therefore Enhanced Sleep Mode Operation of this paper will be useful in case of increase battery life time as well as guaranteeing QoS for MS in IEEE 802.16 system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.80-88
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• 2010

In a conventional system, hydraulic unit pumps out pressurized oil when the power use is not even necessary. As a result, it causes much power loss. This study is on the proposal of new hydraulic unit which controls the revolution of the pump in order to produce proper power needed and to have good response characteristic. In addition, the existing control methods such as PID control method, fuzzy control method, and adaptive control method are applied to the proposed hydraulic unit. Then the best control method is selected and the controller is developed to realize minimum power loss.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.447-450
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• 1991

A novel effective calculation method of the compensation current commands of active power filter using voltage source PWM converter is proposed on the basis of the instantaneous reactive power theory. The load currents and the phase of the source voltages are used for the simplification of the calculations and the reduction of the its time. And the calculation of the currents is performed by DSP 32014 within 50 uSEC. For reducing the DC voltage and saving the costs, a passive power filters are used. The simulation results of the effects of the active power filter with a passive filter are presented.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.505-510
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• 2009

In this paper, building energy analysis and energy cost of power stand up and demand control over the power proposed to reduce power demand. Through analysis of the load power demand special day were able to apply the pattern. In addition, the existing rate of change of load forecasting to reduce the large errors were not previously available data. And daily schedules and special day for considering the exponential smoothing methods were used. Previous year's special day and the previous day due to the uncertainty of the load and the model components were considered. The maximum demand power control simulation using the fuzzy control of power does not exceed the contract. Through simulation, the benefits of the proposed energy-saving techniques were demonstrated.

• Annual Conference of KIPS
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• 2005.05a
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• pp.863-866
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• 2005

Low-power design is one of the most important challenges encountered in maximizing battery life in portable devices as well as saving energy during system operation. In this paper we propose a low-power DCT (Discrete Cosine Transform) architecture using a modified Computation Sharing Multiplication (CSHM). The overall rate of power consume is reduced during DCT: the proposed architecture does not perform arithmetic operations on unnecessary bits during the Computation Sharing Multiplication calculations. Experimental results show that it is possible to reduce power dissipation up to about $7{\sim}8%$ without compromising the final DCT results. The proposed lowpower DCT architecture can be applied to consumer electronics as well as portable multimedia systems requiring high throughput and low-power.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.380-388
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• 2006

In this paper, a novel control algorithm to minimize the power loss of the induction generator for wind power generation system is presented. The proposed method is based on the flux level reduction, where the flux level is computed from the machine model for the optimum d-axis current of the generator. For the vector-controlled induction generator, the d-axis current controls the excitation level in order to minimize the generator loss while the q-axis current controls the generator torque, by which the speed of the induction generator is controlled according to the variation of the wind speed in order to produce the maximum output power. Wind turbine simulator has been implemented in laboratory to validate the theoretical development. The experimental results show that the loss minimization process is more effective at low wind speed and that the percent of power loss saving can approach to 25%. Experimental results are shown to verify the validity of the proposed scheme.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1079-1080
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• 2006

This paper presents the methods to save energy by using load consumption pattern analysis. Base on the substation annual power usage data, the characteristic of the substation power consumption have investigated. With this investigation effective electrical billing condition and the control target load has been determined. Most of power usage comes from the motor car, so power system and load table of motor car were reviewed. And in the metropolitan area the peak power consumption occurs at summer or winter rush hours because of its typical characteristics. From this data control point of time are determined. Through the whole study the methode to control the power Peak consumption are proposed and prototype was designed.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.119-124
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• 2006

This paper deals with energy-saving effort in the hydraulic power steering system. Commonly, the hydraulic power steering systems are used for passenger cars and the reduction of pumping loss under non-steering condition is important to improve fuel economy. Experiments and simulations are performed simultaneously to examine the main factors to reduce the pumping loss-pressure loss and flow rate of the power steering systems. Fuel economy effect of the optimal design of power steering system is verified by vehicle test - more than 1% fuel consuming reduction is attained.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1326-1329
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• 2009

In large-area LCD displays, we have developed two new control technologies for high-power LED backlight. The Novel control technology called scanning control and local gray control. In addition, a conceptual display system power management was developed. We have implemented high power-LED module driving system which can achieve power saving and cost down. Finally, we designed LED light-bar module of the side type as a backlight source. It not only achieved light & thin but also reduced the quantity of LEDs.