• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.171-174
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• 2001

This paper proposes a nonlinear impedance circuit composed by diodes and inductors or capacitors. This circuit needs no control circuits and switches, and the impedance .value is changed by the polarity of current or voltage. and this paper presents one of these applications to improve the input current of capacitor input diode rectifiers. The rectifier using the nonlinear impedance circuit id constructed with four diodes and four capacitors in addition to the conventional rectifiers, that is, it has eight diodes and five capacitors, including a DC link capacitor. It makes harmonic components of the input current reduce and the power factor improve. A circuit design method is shown by experimentation and confirmed simulation. It explained that compared conventional pulse width modulated (PWM) inverter with half pulse-width modulated (HPWM) inverter. Proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.727-728
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• 2000

The Cathodic Protection system which is usually applied to marine metallic structures in domestic is Sacrificial Anode Method. In general. low efficiency rectifiers are using in the field of Cathodic Protection. These rectifiers are not only low efficiency but also manual type which is not able to control remotely. In this paper we describe the high efficiency rectifier used the high speed switching method for optimum corrosion control of marine metallic structures.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1664-1672
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• 2015

This paper proposes a series arc fault detection algorithm which incorporates peak voltage and harmonic current detectors for single-phase boost power factor correction (PFC) rectifiers. The series arc fault model is also proposed to analyze the phenomenon of the arc fault and detection algorithm. For arc detection, the virtual dq transformation is utilized to detect the peak input voltage. In addition, multiple combinations of low- and high-pass filters are applied to extract the specific harmonic components which show the characteristics of the series arc fault conditions. The proposed model and the arc detection method are experimentally verified through a boost PFC rectifier prototype operating under the grid-tied condition with an artificial arc generator manufactured under the guidelines for the Underwriters Laboratories (UL) 1699 standard.

• Journal of Power Electronics
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• v.12 no.4
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• pp.559-566
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• 2012

A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

• Journal of Power Electronics
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• v.12 no.4
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• pp.587-594
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• 2012

When a PWM rectifier has a low DC-link voltage during startup, the output voltage vector cannot be high enough to regulate the input current. This lack of a PWM rectifier output voltage vector can cause an unregulated inrush current when the rectifier operation starts. This paper presents a PWM rectifier start-up current control algorithm for when it starts operation with a lower DC-link voltage than unloaded condition case. To avoid the unregulated inrush current caused by a lack of DC-link voltage, the proposed control scheme regulates the one phase current with one switch chopping and it generates the current command considering the uncontrolled current magnitude information, which is calculated in advance. Simulation and experiment results support the validity of the proposed method.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1044-1048
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• 2001

This paper proposes a nonlinear impedance circuit composed by diodes and inductors or capacitors. This circuit needs no control circuits and switches, and the impedance value is changed by the polarity of current or voltage. This paper presents one of these applications to improve the input current of capacitor input diode rectifiers. The rectifier using the nonlinear impedance circuit id constructed with four diodes and four capacitors in addition to the conventional rectifiers, that is, it has eight diodes and five capacitors, including a DC link capacitor. It makes harmonic components of the input current reduce and the power factor improve. A circuit design method is shown by experimentation and confirmed simulation. It explained that compared conventional pulse-width modulated (PWM)inverter with half pulse-width modulated (HPWM) inverter proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2662-2664
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• 1999

To improve the current waveform of diode rectifiers, we propose a new operating principle for the voltage diode rectifiers. In the conventional voltage rectifier circuit, relatively large capacitors are used to boost the output voltage, while the proposed circuit uses smaller ones and a small reactor not to boost the output voltage but improve the input current waveform. A circuit design method is shown and confirmed simulation. It explained that compared conventional SPWM inverter with HPWM(Half Pulse-width modulated)Inverter. Proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting. Output voltage and current of this paper were applied for real air-conditioner.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1431-1433
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• 1996

Effective ionization coefficients for (100), (110) and (111) oriented gallium arsenide are extracted from the ionization coefficients far electrons and holes. Analytical formulas for the breakdown voltage of the GaAs Schottky rectifiers are derived by employing the ionization coefficients. The breakdown voltages obtained from our analytical model agree fairly well with the numerical results as well as the experimental ones reported in the range of $10^{14}\;cm^{-3}$ - $5{\times}10^{17}\;cm^{-3}$ doping concentrations.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.658-662
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• 1998

A pulse frequency modulation control method for single-switch three-phase buck rectifiers is comprehensively studied in this paper. The proposed pulse frequency control method leads the three-phase buck rectifier to high performance system that can draw the nearly sinusoidal imput-line currents. The simulated and experimental results demonstrate that the system provides low total harmonic distortion of the input-line currents, high-power factor, and good output voltage regulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.6
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• pp.592-600
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• 2000

In this paper, a novel control scheme of three-phase PWM rectifiers using only dc-side sensors is proposed. The phase currents are reconstructed from switching states of the rectifier and the dc output current. For effective current control, the currents are estimated by a predictive state observer. Also, both the phase angle and the magnitude of the source voltage are estimated by controlling the deviation between the model current and the system current to be zero. The validity of the proposed ac phase and current sensorless technique has been verified by experimental results.