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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Transactions of the Korean Institute of Electrical Engineers P
Journal Basic Information
Journal DOI :
The Korean Institute of Electrical Engineers
Editor in Chief :
Volume & Issues
Volume 55, Issue 4 - Dec 2006
Volume 55, Issue 3 - Sep 2006
Volume 55, Issue 2 - Jun 2006
Volume 55, Issue 1 - Mar 2006
Selecting the target year
The Design of UFR with Fast Frequency Measurement Technique
Park, Jong-Chan ; Kim, Byung-Jin ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 1~5
In this paper, the frequency estimator and DFT filter gain compensation for UFR(Under Frequency protection Relay) is introduced. Due to the sudden appearance of generator loads or faults in power system, the frequency is supposed to deviate from its nominal value. Because a frequency calculation is based on phase information, it needs sufficient sampling data to figure out a precious frequency. Therefore the frequency measurement for UFR needs excellent qualities such as high speed and precision with low sampling frequency Authors propose the frequency estimator which compares the vector differences and the DFT filter gain compensation which identifies DFT filter error and correct it. Using the frequency estimator and compensation, UFR which has the 0.01[ms] calculation delay and 0.003[Hz] measurement error is implemented with digital processor.
Testing of Advanced Relaying and Design of Prototype IED for Power Transformer Protection
Park, Chul-Won ; Shin, Myong-Chul ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 6~12
A popular method used by primary protection for power transformer is current ratio differential relaying (RDR) with 2nd harmonic restraints. In modern power transformer due to the use of low-loss amorphous material, the 2nd harmonic component during inrush is significantly reduced. The higher the capacitance of the high voltage status and underground distribution, the more the differential current includes the 2nd harmonic component during internal fault. Thus the conventional method may not operate properly. This paper proposes an advanced relaying algorithm and the prototype IED hardware design and it's real-time experimental results. To evaluate performance of the proposed algorithm, the study is well constructed power system model including power transformer utilizing the EMTP software and the testing is made through simulation of various cases. The proposed relaying that is well constructed using DSP chip and microprocessor etc. has been developed and the prototype IED has been verified through on-line testing. The results show that an advanced relaying based prototype IED never mis-operated and correctly identified all the faults and that inrushes that are applied.
Design of Double Digital Controller to Improve Performance for the Silent Discharging Ozonizer
Park, Jee-Ho ; Kim, Dong-Wan ; Woo, Sung-Hoon ; Roh, In-Bae ; Woo, Jung-In ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 13~20
In this paper, a control method of ozone generator for a tiny deodorizer is proposed, and also a cooling technique is described which is cooling down the flowing air gap into a silent discharger to
to generate ozone of high density and diffusing power. As the digital control system for this method, a double feedback loop is designed which detects the voltage and current of equivalent capacitor of the discharger and compensates for the poor power waveform caused by the noise at high discharging frequency. During the plant modeling of this system, computing time factor is considered as a unique parameter of the power system to improve the respond characteristics with regard to fluctuating load and to replenish the computing time delay of the controller. Through the experiment, sinusoidal input current for discharger can be acquired and all the effectiveness of this accurate control system over unstable ozone discharger are proved.
Instantaneous Voltage Sag Corrector Using Series Compensator in Transfer Power Line Generator
Lee, Sang-Hoon ; Min, Wan-Ki ; Jeon, Byeong-Seok ; Lee, Dae-Jong ; Hong, Hyun-Mun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 21~25
This paper describes the novel control techniques design of VSC(Voltage Sag Corrector) for the purpose of power line quality enhancement. A fast detecting technique of voltage sag is implemented through the detection of instantaneous value on synchronous rotating do-reference frame. The first order digital filter is added in the detection algorithm to protect the insensitive characteristics against the noise. The relationship between the total detection time and cut-off frequency of the filter is described. The size of the capacitor bank used as the energy storage element is designed from the point of view of input/output energy with circuit analysis. Finally, the validity of the proposed scheme is proven through the simulated results.
The Design and fabrication of Capacitive Humidity Sensor Having Interdigital Electrodes and Its Signal Processing Circuit
Kang, Jeong-Ho ; Lee, Jae-Yong ; Kim, Woo-Hyun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 26~30
For the purpose of developing capacitive humidity sensor having interdigital electrodes, interdigital electrode was modeled and simulated to obtain capacitance and sensitivity as a function of geometric parameters like the structural gap and thickness. For the development of ASIC, switched capacitor signal processing circuits for capacitive humidity sensor were designed and simulated by Cadence using
CMOS process parameters. The signal processing circuits are composed of amplifier for voltage gain control, and clock generator for sensor driving and switch control. The characteristics of the fabricated sensors are; 1) sensitivity is 9fF/%R.H., 2) temperature coefficient of offset(TCO) is
, 3) nonlinearity is 1.2%FS, 4) hysteresis is 1.5%FS in humidity range of
. The response time is 50 seconds in adsorption and 70 seconds in desorption. Fabricated process used in this capacitive humidity sensor having interdigital electrode are just as similar as conventional IC process technology. Therefore this can be easily mass produced with low cost, simple circuit and utilized in many applications for both industrial and environmental measurement and control system, such as monitoring system of environment, automobile, displayer, IC process room, and laboratory etc.
A Study on the Pressure Sensor for the Direct Detection of the Approach to the Dangerous Power Facilities Using Pb-free BNKT Ceramics
Hong, Jae-Il ; Yoo, Ju-Hyun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 31~34
A infrared rays sensor or ultrasonic sensor can detect the object at the narrow area, however a pressure sensor can detect man and animal at the wide area. It is necessary to manufacture the sensor by using Pb-free ceramics in the respect of environmental protection. Piezoelectric properties of ceramics added 0.2wt%
were 0.4 of kp,
. The output voltage of the pressure sensor is 0.48 V at 20 in
. The output voltage of the pressure sensor with driving circuit is 9.8 V, 37 ms width.
A Study on Optimal Operation of Summer Season Cooling System with Numbers of Heat Pumps
Shin, Kwan-Woo ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 35~40
Heat-pump system has a special feature that provides heating operation in winter season and cooling operation in summer season with a single system. It also has a merit that absorbs and makes use of wastewater heat, terrestrial heat, and heat energy from the air. Because heat-pump system uses midnight electric power, it decreases power peak load and is very economical as a result. By using the property that energy source is converted to low temperature when losing the heat, high temperature energy source is used to provide heating water and low temperature energy source is used to provide cooling water simultaneously in summer season. This study made up a heat-pump system with 4 air heat sources and a water heat source and implemented the optimal operation algorithm that works with numbers of heat pumps to operate them efficiently. With the heat-pump system, we applied it to cooling and heating operation in summer season operation mode in a real building.
Parallel Running of Induction Motor using Anti-slip Controller
Kim, Jung-Gyo ; Lee, Ju ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 41~46
In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a anti-slip control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the anti-slip control is performed to obtain the maximum transfer of the tractive effort.
The Comparison of Two Control Algorithm for a Voltage Bus Conditioner in a DC Power Distribution System
La, Jae-Du ; Lee, Yong-Geun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 55, issue 1, 2006, Pages 47~53
A Voltage Bus Conditioner (VBC) is used to mitigate the voltage transients on a common power distribution bus. The VBC described here utilises inductive storage and unlike its counter part with capacitive storage, it can employ the entire stored energy towards transients' mitigation. The performances of adaptive duty ratio control and sliding mode control have been compared. The simulation results (with the package SABER) indicate that the sliding mode control results in the shortest and the smallest bus voltage excursions.