• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1972-1977
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• 2011

The mechanical integrity of generator stator windings is one of the critical point because the electric power is generated and conducted to power system through these windings. To cool down the heat emitted from generator winding during its operation, a majority of generators use de-mineralized water characterized by high cooling efficiency. Contrary to such the excellent cooling efficiency, however, the damaged bar insulations attributed to the absorption of cooling water in the generator stator winding lead to highly time- and cost consuming efforts as well as to service deterioration due to unexpected forced outage of generator. It is described that the new design of water absorption sensor using cross capacitance for generator in power plant in order to increase the reliability of water absorption diagnostics for generator stator bar insulation.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2192-2201
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• 2016

Wind energy is currently the fastest-growing electricity source worldwide. The cost efficiency of wind generators must be high because these generators have to compete with other energy sources. In this paper, a system that utilizes an open-winding permanent-magnet synchronous generator is studied for wind-energy generation. The proposed system controls generated power through an auxiliary voltage source inverter. The VA rating of the auxiliary inverter is only a fraction of the system-rated power. An adjusted control system, which consists of two main parts, is implemented to control the generator power and the grid-side converter. This paper introduces a study on the effect of unbalanced voltages for the wind-generation system. The proposed system is designed and simulated using MATLAB/Simulink software. Theoretical and experimental results verify the validity of the proposed system to achieve the power management requirements for balanced and unbalanced voltage conditions of the grid.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.4
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• pp.273-279
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• 2000

Electrical repair method which has replaced laser repair method can replace defective cell by redundancy’s in the redundancy scheme of conventional high density memory. This electrical repair circuit consists of the antifuse program/read/latch circuits, a clock generator a negative voltage generator a power-up pulse circuit a special address mux and etc. The measured program voltage of made antifuses was 7.2~7.5V and the resistance of programmed antifuses was below 500 Ω. The period of clock generator was about 30 ns. The output voltage of a negative voltage generator was about 4.3 V and the current capacity was maximum 825 $mutextrm{A}$. An antifuse was programmed using by the electric potential difference between supply-voltage (3.3 V) and output voltage generator. The output pulse width of a power-up pulse circuit was 30 ns ~ 1$mutextrm{s}$ with the variation of power-up time. The programmed antifuse resistance required below 44 ㏀ from the simulation of antifuse program/read/latch circuit. Therefore the electrical repair circuit behaved safely and the yield of high densitymemory will be increased by using the circuit.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.209-211
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• 1995

This paper is concerned with High Frequency, High Voltage Generator for X-ray using zero-voltage soft-switching PWM DC-DC high-power converter by Resonant method, which makes the most of the parastic LC parameters of high-voltage transformer link, for diagnostic X-ray power generator. The converter circuit basically utilizes phase-shift pulse width modulated series Resonant full-bridge PWM DC-DC high-power converter operating at a constant frequency;25kHz. The converter output regulation is digitally controlled using DSP (Digital Signal Processor) for obtaining a fast rising time and adjust output voltage within a wide load range.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.42-49
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• 2000

This paper presents the application of a FARMA controller to stabilization of nonlinear Two-Generator Five-Bus power Systems. The control rules and the membership functions of the FARMA controller are generated automatically without using any plant model high complexity and severe nonlinearity of power systems are introduced and two-Machine Five -Bus Power system stabilization problem is formulated. The simulation results demonstrate the effectiveness and application possibility of the FARMA controller to the control problem of high order and nonlinear plants.

• Journal of Power Electronics
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• v.11 no.4
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• pp.527-532
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• 2011

Due to the need for improved fuel consumption and the trend towards increasing the electrical content in automobiles, integrated starter generator (ISG) systems are being considered by the automotive industry. In this paper, in order to change the conventional generator of a vehicle, a belt driven integrated starter generator is considered. The overall ISG system, the design considerations for the claw pole type AC electric machine and a low voltage very high current power stage implementation are discussed. Test data on the low voltage claw pole type machine is presented, and a large current voltage source DC/AC inverter suitable for low voltage integrated starter generator operation is also presented. A metal based PCB (Printed Circuit Board) power unit to attach the 4-parallel MOS-FETs is used to achieve extremely high current capability. Furthermore, issues related to the torque assistance during vehicle acceleration and the generation/regeneration characteristics are discussed. A prototype with the capability of up to 1000 A and 27 V is designed and built to validate the kilo-amp inverter.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.69-72
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• 2002

In this study, We proposed high efficiency wind power generator system for induction generator used SVPWM swiching inverter. First, We propose Equivalient Circuit for Induction Generator, it's characteristics equation, and power equation of slip. In addition, we suggest Pick Power Traction Slip control methods, adapted variable wind power system. We study simulation result for the proposed system and output power by slip effect. and we identify SVPWM of suitable wind power system by comparison between SPWM and SVPWM Consequently, we show that the system control result from variable wind power is suitable.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1003-1004
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• 2011

In this paper, the Interior Permanent Magnet Generator utilizing the power of the robot engine was designed. We designed considering the required power of the auxiliary power to be also used in robot. The rotor which is suitable for the high speed operation was designed. And the generator which utilized this finite element method (FEM) and can deliver the optimum output to the auxiliary power was designed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.103-107
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• 2016

In general, the voltage stability of induction generator is lower than synchronous generator. Induction generator has a number of advantages over the synchronous generator on the side of price and maintenance. So Induction generator has been applied to the small hydroelectric power of low output. Induction generator usually generates a high current during grid connection. The high current that occurs during grid connection can cause a voltage drop in the system. In order to increase the supply of the induction generator, it is necessary to propose a method of reducing high current. This paper proposes some method of the soft start to reduce voltage drop caused by the large starting current. soft-start method has high voltage drop effect than direct start method, control of firing angle can be increased the voltage drop effect.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.218-221
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• 2006

In this paper, a high-voltage generator with several mA draw output currents using LTPS-TFT technology is proposed. The new generator can be efficiently boosted about +18V output voltages with 5mA draw output currents and power efficiency ${\eta}$ is around 84% under the conditions of +5V power-supply voltage and 250kHz frequency.