• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.921-930
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• 2016

This paper proposes a design and control method for a high-voltage direction current modular multilevel converter (HVDC-MMC) considering the capacitor voltage ripple of the submodule (SM). The capacitor voltage ripple consists of the line frequency and double-line-frequency components. The double line- frequency component does not fluctuate according to the active power, whereas the line-frequency component is highly influenced by the grid-side voltage and current. If the grid voltage drops, a conventional converter increases the current to maintain the active power. A grid voltage drops, current increment, or both occur with a capacitor voltage ripple higher than the limit value. In order to reliably control an MMC within a limit value, the SM capacitor should be designed on the basis of the capacitor voltage ripple. In this paper, the capacitor voltage ripple according to the grid voltage and current are analyzed, and the proposed control method includes a current limitation method considering the capacitor voltage ripple. The proposed design and control method are verified through simulation using PSCAD/EMTDC.

• 전력전자학회논문지
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• 제27권4호
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• pp.325-331
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• 2022

This study proposes a design method that minimizes a conduction loss of LCC resonant converter under rated condition. Through a simplified analysis of the waveform of the resonant current, the power transfer section and RMS value of the resonant current was analyzed mathematically and graphically. Based on this analysis, the design method that minimizes the RMS value of the resonant current is proposed. To demonstrate this method, this study designed a 7.5 kW (100 V, 75 A) capacitor charger based on LCC resonant converter and the design parameters were chosen according to the process of the design method. Then, the capacitor charger was implemented. An experiment was conducted to measure efficiency while satisfying design specifications under rated conditions. This design method was verified to be effective by achieving 97.7% maximum efficiency and design specifications under rated conditions.

• 한국자기학회지
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• 제5권5호
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• pp.828-832
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• 1995

This paper describes the efficient design, analysis method and experimental verification of capacitor discharge impulse magnetizer system. A capacitor discharge magnetizer system is used to produce a high current impulse of short duration in this magnetizing fixture. The parasitic resistance and parasitic inductance of the capacitor discharge impulse magnetizer system have been estimated using known air-core test coil. Finite element analysis (using MAXWELL 2-D field simulator) and magnetizing circuit analysis (using SPICE) are also used as part of the design and analysis process of the capacitor discharge impulse magnetizer system. Application study for a magnetizing fixture design is shown. 8-pole magnetizing fixture has been designed and analyzed using finite element analysis. The fixture design for 8-pole magnet are presented along with the experimental results. The experimental results have been achieved using a high-voltage, high-energy capacitor discharge impulse magnetizer and 8-pole iron core fixtures (charging voltage : 2000[V], capacitor bank : 4000[$\mu\textrm{F}$]).

• Journal of Power Electronics
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• 제13권4호
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• pp.558-568
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• 2013

In this paper, a new decoupling technique for a flyback inverter using an active power decoupling circuit with auxiliary winding and a novel switching pattern is proposed. The conventional passive power decoupling method is applied to control Maximum Power Point Tracking (MPPT) efficiently by attenuating double frequency power pulsation on the photovoltaic (PV) side. In this case, decoupling capacitor for a flyback inverter is essentially required large electrolytic capacitor of milli-farads. However using the electrolytic capacitor have problems of bulky size and short life-span. Because this electrolytic capacitor is strongly concerned with the life-span of an AC module system, an active power decoupling circuit to minimize input capacitance is needed. In the proposed topology, auxiliary winding defined as a Ripple port will partially cover difference between a PV power and an AC Power. Since input capacitor and auxiliary capacitor is reduced by Ripple port, it can be replaced by a film capacitor. To perform the operation of charging/discharging decoupling capacitor $C_x$, a novel switching sequence is also proposed. The proposed topology is verified by design analysis, simulation and experimental results.

• 전력전자학회논문지
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• 제17권5호
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• pp.453-460
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• 2012

This paper proposes the method to design the parameters of an impedance network at three-phase QZSI(quasi Z-source inverter) by considering an equivalent series resistance (ESR) in the capacitor. The equations of both two capacitor voltages and two inductor currents are derived at three operating modes of the QZSI. The capacitor voltage ripples caused by the ESR in the capacitor at the transition state of operating modes are calculated. Based on the ripples of both the capacitor voltages and inductor currents, the optimal values of capacitor and inductor are designed. The simulation studies using PSIM and experimental results with DSP are carried out to verify the performance of design method.

• 전기의세계
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• 제31권2호
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• pp.132-140
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• 1982

Designing the capacitor-run motor for balanced operation is accompanied with the excessive capacitor value and low capacitor terminal voltage of condenser. As a solution for this problems, It was reported the design by equal volt-ampere method. The running characteristics of capacitor-run motor by this method due to the balancing point selection, however, has a room to be studied further. This paper deals with the determination of the winding ratio and capacitor value of a permarient-split capacitor motor by balanced operation and equal volt-ampere method at the different load points. The analysis of the running characteristics of a motor and its designing method also presented for both cases. It concluded that the running characteristics due to the equal volt-ampere operation are very close to the balanced operation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.223-224
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• 2011

This paper presents the method to design the inductor and capacitor value considering the ripple component that may be generated by three operating states of the Quasi Z source inverter at the impedance network. Based on the analysis of each operation mode, the equations of the capacitor voltage and inductor current are derived. In order to simplify the design processing, design equations of the impedance network are derived where the capacitor voltage and inductor current are lineared. The validity of the design method is verified with the simulation result using PSIM.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.203-204
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• 2012

This paper presents the method to design the inductor and capacitor value considering the ripple component that may be generated by three operating states of the Quasi Z-source inverter at the impedance network. Based on the analysis of each operation mode, the equations of the capacitor voltage and inductor current are derived. In order to simplify the design processing, design equations of the impedance network are derived where the capacitor voltage and inductor current are lineared. The validity of the design method is verified with the simulation result using PSIM and experimental result using 32-bit DSP.

• 전기학회논문지
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• 제62권4호
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• pp.510-516
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• 2013

This paper suggests a 3-phase series-resonant type high voltage capacitor charger for an EML pulsed power system. The operating principle on the charger is explained by an equivalent circuit. Additionally, we analyze the charging characteristic in one discontinuous conduction mode and three continuous conduction modes. The analysis shows that the resonant current per phase is two thirds of the 3-phase charger's average charging current and one third of the single-phase charger's average charging current with the same capacity. We suggest a design method of the 3-phase capacitor charger in each operational mode and present an example of 3.5 kW capacitor charger at ${\omega}_s=0.33{\omega}_r$. The 3.5 kW 3-phase capacitor charger prototype is assembled with a TI28335 controller and a 40 kJ, 7 kV capacitor. The design rules based on the analysis are verified by experiment.

• 대한전기학회논문지
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• 제43권2호
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• pp.206-215
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• 1994

A method for simulating general characteristics and temperature characteristics of discharging SCR of the capacitor discharge impulse magnetizer-magnetizing fixture system using SPICE is presented. This method has been developed which can aid the design, understanding and inexpensive, time-saving of magnetizing circuit. As the detailed characteristic of magnetizing circuit can be obtained, the efficient design of the magntizing circuit which produce desired magnet will be possible using our SPICE modeling. Especially, computation of the temperature rise of discharging SCR is very important since it gives some indication of thermal characteristic of discharging circuit. It is implemented on a 486 personal computer, and the modeling results are checked against experimental measures. The experimental results have been achived using 305[V] and 607[V] charging voltage, low-energy capacitor discharge impulse magnetizer-magnetizing fixture of air cleaner DC motor.