• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.268-272
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• 2016

A brush-less type synchronous generator is driven by an internal-combustion engine that is used for emergency source. This kind of generator has to maintain output voltage in a range of some degree under the abrupt load irregular conditions such as a full load trip. This paper suggests a suppression method of increasing the output voltage over the rating. Automatic voltage regulator detects excessive rising of output voltage of the generator and supplies the signals to a switch installed in the rotating exciter through the photo-coupler. The current of main field rapidly decreases by additional resistor of the main filed circuit. Therefore, the output voltage of the generator is maintained effectively. The experimental results verified that the excessive value of the output voltage is limited in the range of 7% of the rated voltage.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.83-94
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• 1994

Performance test result on prototype car equipped with low-band type active suspension system is reported. Control theory is explained first. Simulation for feasibility and parameter tuning, control module test using hydraulic exciter and test run, and performance evaluation of the test car on test track are reported successively. Emphasis was put on modification of control theory which caused many unexpected problems in actual implementation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.218-223
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• 2007

This paper presents a simple, robust excitation control system for synchronous generator using direct instantaneous voltage control(DIVC) method. The proposed DIVC excitation system can operate as high dynamics of power conversion system without any control gains such as Pill controller. And the transient overshoot of generator voltage can be suppressed with a simple time constant. For the continuous control of excitation system, the fast IGBT inverter system is used in this paper for exciter's field control. The proposed control scheme is verified by the computer simulations and experimental results in the prototype generation system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.147-152
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• 1999

Semiconductor piezoresistive type vibration sensor was fabricated by using semiconductor process and micromachining technology. To measure the micro electromagnetic force between coil and magnet, fabricated vibration sensor was used. Toapply micro electromagnetic force produced from the micro exciter, small-sized NdFeB permanent magnet was attached on the mass of the fabricated vibration sensor. The measured electromagnetic force are about 5~180dyne when the applied sinusoidal current of 1KHz in the range of 1.5~8mA. The measurement of micro electromagnetic forcewas performed by changing the distance between coil and magnet. Output characteristics of micro electromagnetic force according to the applied coil current were linear. Furthermore, output results were used to get the transfer constant that is important to decide the efficiency and the performance of the coil and magnet.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.562-565
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• 2001

In this paper, novel device structures in order to realize ultra fast and ultra small silicon devices are investigated using ultra-high vacuum chemical vapor deposition(UHVCVD) and Excimer Laser Annealing (ELA). Based on these fundamental technologies for the deep sub-micron device, high speed and low power devices can be fabricated. These junction formation technologies based on damage-free process for replacing of low energy ion implantation involve solid phase diffusion and vapor phase diffusion. As a result, ultra shallow junction depths by ELA are analyzed to 10~20nm for arsenic dosage(2${\times}$10$\_$14//$\textrm{cm}^2$), exciter laser source(λ=248nm) is KrF, and sheet resistances are measured to 1k$\Omega$/$\square$ at junction depth of 15nm and realized sub-50nm n-MOSFET.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.319-322
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• 2005

This paper describes practical tuning methods and testing of a digital PSS, which uses both frequency and power, with the 220MVA Chungpyung P/P #1 in the KEPCO system to enhance the damping of local modes. In the first step, the objective phase of PSS is computed through a phase leading function to provide compensation between the exciter reference point and the generator air-gap torque before tuning the PSS's time constants. In addition, eigenvalue analysis was used to determine a range of PSS's gain, whichis the more useful for field testing rather than a single gain value. The Real-Time Digital Simulator was used to verify safe operations of the PSS in the presence of disturbances, such as AVR step and three phase fault.

• Proceedings of the KIEE Conference
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• summer
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• pp.239-241
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• 2004

The purpose of this paper is to explain techniques achieved while developing a transient stability program which is suitable to Korean power system. It concentrates on the development of a synchronous machine model, exciter models and turbine-governor models used in large-scale power system stability analysis. These proposed models enhance the performance of the developing program. This developing program has been tested with the KEPCO system, and the simulation results obtained from the program are compared to those of commercial programs.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1060-1062
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• 1999

This paper proposes a guideline of choosing the optimum stabilizer input considering the gain margin of power system stabilizer between the optimum stabilizer gain and the allowable maximum stabilizer gain in accordance with the five inputs, such as generator shaft speed, bus frequency, electrical power, accelerating power and bus terminal voltage. The local mode damping and exciter mode damping are considered with increasing the stabilizer gain to determine each gain margin of the inputs.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.113-117
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• 1992

This paper is discribed to the application of PID controller for the frequency control of power systems. The proposed optimal PID controller is designed to obtain gain Parameters of P,I,D's coefficients according to optimization technique using the relatively ingeneous simplex method. The PID controller which is applied to one area, tie-line two area with(or without) exciter is showed good performance rather than that of optimal Pl controllor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.57-60
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• 2005

Modal parameters of a structure are the important factor to control the missile maneuver. In general, a dummy structure is used for the modal test of missile structure instead of the real warhead and propellant because there may be the danger of a explosion by the electric shock of test equipment, such as the exciter and the power amplifier. However, the modal testing of a real missile structure is required to acquire the modal parameters and to analyze the missile performance accurately. The new test system and technique are developed to get rid of the danger and secure the safety during the testing. This test system is made of with the computer network system and controlled remote from test site. Using His new test system, the modal test of real missile structure is performed successfully and its validity is proven.