• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1991.10a
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• pp.59-63
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• 1991

Fuel cells power generating system converts the chemical energy of a fuel directly into electrical energy. The merits of fuel cells power generating system are pollution free and high energy conversion efficiency. Fuel cells power generating system includes the DC/AC converter. DC source obtained from stack is converted to the constant AC voltage or current by the inverter. In this paper, the power conditioner for the fuel cells power generating system are discribed. Some experiments are performed, for the power conversion system. The results show that the implimented experimental system may be applied to the practical fuel cells power generating system.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.500-503
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• 1991

Fuel cells power generating system converts the chemical energy of a fuel directly into electrical energy. The merits of fuel cells power generating system are pollution free and high energy conversion efficiency. Fuel cells power generating system includes the DC/AC converter. DC source obtained from stack is converted to the constant AC voltage or current by the inverter. In this paper, the power control techniques for the fuel cells power generating system are described.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.185-192
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• 1996

This paper presents a design of vertical axis Darrieus wind turbine combine with Savonius for wind-power generating system to be adapted for variable wind speed. The wind turbine consists of two troposkien- and four Savonius-blades. Darrieus turbine is designed with diameter 9.4[m], chord length 380[mm], tip speed ratio 5. Savonius turbine is designed with diameter 1.8[m], height 2[m], tip speed ratio 0.95. The design of turbine is laid for the main data of rated wind speed 10[m/s], turbine speed 101.4[rpm]. The generating power is estimated to maximum power 20[kW], and this is converted to commercial power line by means of three phase synchronous generator-inverter system. Generating system is designed for operation on VSVF(variable speed variable frequency) condition and constant voltage system.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.38-43
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• 2013

We derive the Z-parameters for the two coupled antennas used for wireless power transfer under the assumption that the antennas are canonical minimum scattering antennas. Using the Z-parameter and the maximum power transfer efficiency formula, we determine the maximum power transfer efficiency of wireless power transfer systems. The results showed that the maximum power transfer efficiency increases as the mode number or the radiation efficiency increases. To verify the theory, we fabricate and measure two different power transfer systems: one comprises two antennas generating $TM_{01}$ mode; the other comprises two antennas generating $TM_{02}$ mode. When the distance between the centers of the antennas was 30 cm, the maximum power transfer efficiency of the antennas generating the $TM_{02}$ mode increased by 62 % compared to that of the antennas generating the $TM_{01}$ mode.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.326-329
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• 1997

This paper deals with the generating power analysis of wound rotor induction generator according to the rotor excitation for use of DFIG (Doubly Fed Induction Generator) system in wind power generation as a part of renewable energy development. In this way, the generating power of wound rotor induction generator can be achieved for a wide range wind speed of supersynchronous and subsynchronous speed.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3365-3370
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• 2007

We developed micro power generation system using piezoelectric materials. In our system, the ambient vibrating energy is converting to electric energy by deflection of piezoelectric beams. The system consists of energy generating parts, converting enhancement parts, electric regulation and charging parts, and interface with small-energy-consuming mobile devices. The geometry of piezoelectric beams, the source of vibrating energy, and the electric load of target application determine the characteristics of generating electric power, such as impedance, voltage, current and power density. Therefore, we made a model for analysis of generating power with given information such as piezoelectric materials, geometry, vibration type, and mass. With this model, we can calculate capacitance of piezoelectric beams, generating voltage, current, and power. To obtain maximum energy transfer efficiency, we approached this study in the view of material, electrical, and mechanical engineering

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.567-570
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• 2002

In variable speed wind power generating system connected in power grid, how to capture the maximum wind energy is most important thing Using the doubly fed induction machine as a generator in wind power generating system, it is possible to control the bidirectional slip power between grid and rotor side. This means that we can control the generating power under subsynchronous speed. To verify the theoretical analysis, computer simulation results using Psim program are presented to support the discussion.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.162-165
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• 2003

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM)voltage control for plasma sterilization are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.52-54
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• 2002

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM) voltage control for plasma sterilization are described, For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc.. PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with 6.5[kHz], 1.8[kW] inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1172-1174
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• 2003

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM)voltage control for plasma sterilization are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.