• Journal of the Institute of Convergence Signal Processing
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• v.8 no.3
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• pp.199-204
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• 2007

This paper presents design of interleave configured dc-dc converter for high power distributed power system applications. The multi channel interleaving buck converter with small inductance has proved to be suitable for micro-grid, requiring medium output voltages, high output currents and fast transient response. Integrated magnetic components are used to reduce the size of the converter and improve efficiency. Unlike conventional methods, the distributed approach requires no centralized control, automatically accommodates varying numbers of converter cells, and is highly tolerant of subsystem failures. A general methodology for achieving distributed interleaving is proposed, along with a specific implementation approach. The design and simulation verification of switching frequency 10 kHz system is presented with interleaved clocking of the converter cells. The simulation (simulated by PSIM 6.1) results corroborate the analytical predictions and demonstrate the tremendous benefits of the distributed interleaving approach.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.240-242
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• 1994

Diode and thyristor-based bridge converter have been used for ac/dc conversion. Comparatively, diode bridges are simpler, more robust, less expensive and have a better power factor. However when voltage regulation is required, the thyristor-based phase-controlled converter have been used. But their use is limited by the low power factor and considerable harmonics in the input and output. An ac/dc power conversion scheme capable of fine output voltage control is investigated in this paper.

• Journal of Power Electronics
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• v.5 no.3
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• pp.190-197
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• 2005

This paper presents a technique to reduce the low frequency ripple voltage of the dc output in a BIFRED converter with a small-sized energy storage capacitor. The proposed pulse width control method can be effectively used to suppress the low frequency ripple appeared in the dc output and still maintains generally good performance such as low THD of input line current and a high power factor. Using the small-sized energy storage capacitor, it has better merits of low cost and smaller size than a conventional BIFRED converter. The proposed technique is illustrated its validity and effectiveness through simulations.

• Proceedings of the KIPE Conference
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• 1998.11a
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• pp.55-59
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• 1998

By this time, Diode Rectifier or SCR has been used to gain DC Voltage for Electrolysis Power. Generally DC Voltage is produced from rectifier shall be transformed before rectifier using step-down transformer to obtain adaptable DC Voltage, rectifier output. In the same way, rectifier using SCR shall obtain output voltage after step-down voltage through transformer and control of the SCR firing angle. Transformer shall be used for this two methods to adjust the voltage. But the size and weight of the transformer are increased in accordance with the increase of capacity, and the hardships are accompanied in workspace or transportation. Besides, only the value of input voltage is possible to be regulated, and the expectation of current control is almost impossible during Electrolysis. This study has conducted Design and Simulation to reduce the size and weight of transformer and to be enable voltage and current control of Electrolysis power through high-speed switching using Inverter, Electronics device.

• Journal of Power Electronics
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• v.17 no.1
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• pp.1-10
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• 2017

This paper presents a novel predictive digital control method for boundary conduction mode PFC converters without the need for detecting the inductor current. In the proposed method, the inductor current is predicted by analytical equations instead of being detected by a sensing-resistor. The predicted zero-crossing point of the inductor current is determined by the values of the input voltage, output voltage and predicted inductor current. Importantly, the prediction of zero-crossing point is achieved in just a single switching cycle. Therefore, the errors in predictive calculation caused by parameter variations can be compensated. The prediction of the zero-crossing point with the proposed method has been shown to have good accuracy. The proposed method also shows high stability towards variations in both the inductance and output power. Experimental results demonstrate the effectiveness of the proposed predictive digital control method for PFC converters.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2198-2204
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• 2003

In order to make a match of the insufficient direct solar radiation, in this study, the target output is lowered to 9 kW smaller than 25 kW in former studies. It is also necessary to match the collector/receiver with engine/generator systems to accomplish the power level of a system. The simulation analyses of a dish solar power system with stirling engine are totally carried out to predict the system performance with the designed values. In addition, an influence of direct solar radiation on system performance and operation control is discussed in simulation. It is found that the diameter of concentrator could be made small to 8 m regardless of slope errors with 2.5 and 5.0 mrad radiation, and the operation range of mean pressure control. is wide even if the direct solar radiation is a quit low.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1142-1152
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• 2019

This paper presents a control method for reducing the current distortion in an indirect matrix converter (IMC) operating in boost mode under unbalanced input conditions. IMCs operating in boost mode are useful in distributed generation (DG) systems. They are connected with renewable energy systems (RESs) and the grid to transmit the power generated by the RES. However, under unbalanced voltage conditions of the RES, which is connected with the input stage of the IMC operating in boost mode, the input-output currents are distorted. In particular, the output current distortions cause a ripple of the power, which is transferred to the grid. This aggravates the reliability and stability of the DG system. Therefore, in this paper, a control method using positive/negative sequence voltages and currents is proposed for reducing the current distortion of both side in IMCs operating in boost mode. Simulation and experimental results have been presented to validate effectiveness of the proposed control method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.29-36
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• 1996

A procedure for the predictive control for structural vibration control in building subject to wind loads is presented. The building motions are modeled by the first mode of the response. Wind velocities are generated by the simulation using power spectral density function. Predictive control algorithm is the discrete-time formulation and that is developed as a control strategy that computes the control signal which makes the predicted process output equal to a desired process output. Results on the reduction of the dynamic response and control effectiveness of the algorithm are presented and discussed.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.1
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• pp.47-58
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• 2018

A solar array simulator (SAS) consists of an engine that generates a setpoint according to panel characteristics, a power stage that provides the actual output, and a controller. Particularly, if the control method is not suitable due to the nonlinearity of the solar panel output curve depending on the irradiation amount and the temperature, and the variation of the curve factor depending on the various panel materials, then the panel simulation function cannot be performed properly. Current and voltage mode controls are usually used for the conventional control method. However, these control methods deteriorate the control performance near the maximum power point; thus, a hybrid control method using two or more controllers has been investigated. In this study, we analyze the hybrid control method using three controllers divided into different areas. The design equation of the controller is derived based on the small signal modeling of each controller, and the simulation performance of the solar array simulator verifies its stability and response speed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.14-21
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• 2009

In this paper, a Ka-band 10 W power amplifier module with seven power MMIC bare dies is designed and fabricated using MIC technology which combines multiple MMIC chips on a thin film substrate. Modified Wilkinson power dividers/combiners and CBFGCPW-Microstrip transitions for suppressing resonance and reducing connection loss are utilized for high-gain and high-power millimeter wave modules. A new TTL pulse timing control scheme is proposed to improve output power degradation due to large bypass capacitors in the gate bias circuit. Pulse-mode operation time is extended more than 200 nsec and output power increase of 0.62 W is achieved by applying the proposed scheme to the Ka-band 10 W power amplifier module operating in the pulsed condition of 10 kHz and $5\;{\mu}sec$. The implemented power amplifier module shows a power gain of 59.5 dB and an output power of 11.89 W.