• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.119-123
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• 2001

In this paper, a DCM operated boost integrated single-stage forward-flyback converter is proposed. This proposed converter has high power factor, low harmonic distortion, and tight output regulation. To increase efficiency, zero voltage switching with asymmetrical control is used. This converter also give low voltage stress in switch and this results in low conduction loss with low turn-on resistance.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.129-132
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• 2001

Recently, a ZVT boost converter is embedded in a power factor correction system. The control circuit of the converter assures soft-switching for all the MOSFETs and load regulation. The PFC system contains additional control circuits which assure the input voltage in a sinusoidal form and feed-forward line voltage regulation. In this paper, a soft switching boost converter with zero-voltage transition(ZVT) main switch using zero-current switching(ZCS) auxiliary switch is proposed. Operating intervals of the converter are persented and analyzed. The proposed results show that the main switch maintains UT while auxiliary switch retains ZCS for the complete specified line and load conditions.

• Journal of Power Electronics
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• v.7 no.4
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• pp.310-317
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• 2007

In this paper, an analysis and hysteretic controller design of a $3^{rd}$ order buck converter is presented. The proposed hysteretic controller consists of an inner current-loop, just like the conventional cascade control scheme, and an outer voltage-loop for load voltage regulation. Although it is possible to include an inner current loop from different branches of the converter, from the feasibility and operational point of view, the load side capacitor current would be the better choice. The addition of an inner current-loop improves the dynamic performance of the converter while preserving the robustness of the hysteretic control. The controller formulation and closed-loop converter performance analysis are validated through computer simulations. Few experimental results of the proposed converter are given and compared with the buck converter.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2076-2078
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• 1998

This paper presents STATCON(Static Condenser) control schemes for voltage regulation, power factor correction and harmonics mitigation. Each control scheme can be applied in the system depending on the system requirements. The 20KVA STATCON is developed and tested in the reduced system model for the verification of three different control algorithms. The results of proposed controls are compared for power factor correction and voltage regulation algorithms. For each algorithm, harmonic mitigation scheme is adopted as a part of control. Finally verification of STATCON for the transient response is implemented by voltage flicker test.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.4
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• pp.46-49
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• 1975

Mallory의 회로를 변형하여 변압기를 사용하지 않은 새로운 배전압회로를 구성하였고 직류출력전압의 regulation에 있어서 Mallory의 회로보다 훨씬 우수한 결과를 얻었다. 또 출력파형을 해석하고, 직류출력전압과 출력전류와의 관계를 간결한 반사식으로서 표현하였고 이 관계식이 실험결과와 잘 부합되어 있음을 보였다. In this paper, a new transless voltage doubler circuit which is a modification of Mallory circuit is proposed, Regulation characteristics of the new circuit is much superior to that of Mallory's. The analysis of output waveform is applied, an4 a simple and practical relation between dc output voltage and dc output current is derived. It is shown that this formula is coincide with the experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.71-78
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• 2012

This paper presents a digital control solution to process capacitor current feedback of high performance single-phase UPS for non-linear loads. In all UPS the goal is to maintain the desired output voltage waveform and RMS value over all unknown load conditions and transient response. The proposed UPS uses instantaneous load voltage and filter capacitor current feedback, which is based on the double regulation loop such as the outer voltage control loop and inner current control loop. The proposed DSP-based digital-controlled PWM inverter system has fast dynamic response and low total harmonic distortion (THD) for nonlinear load. The control system was implemented on a 32bit Floating-point DSP controller TMS320C32 and tested on a 5[KVA] IGBT based inverter switching at 11[Khz]. The validity of the proposed scheme is investigated through simulation and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.601-607
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• 1999

본 논문에서는 순간전압조정, 역률 보상, 고조파 저감에 대한 배전용 정지형 동기조상기(STATCOM : STATic COMpensator)에 대한 다양한 제어 모드를 제안하고 있다. 이러한 제어 알고리즘의 성능을 검증하기 위해 각 제어 알고리즘을 20kVA의 축소형 STATCOM에 적용하고 간단한 배전계통을 꾸며 시험하였다. 실험결과로부터 제안한 제어알고리즘이 Custom Power 시스템으로 훌륭한 성능을 보임을 확인할 수 있었다. 실재 배전계통에 적용하여 현재 1MVA STATCOM이 성공적으로 운전되고 있다.

• Journal of Power Electronics
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• v.15 no.4
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• pp.886-898
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• 2015

The design feasibility of a micro unidirectional DC transmission system based on an input-parallel output-parallel (IPOP) converter is analyzed in this paper. The system consists of two subsystems: an input-parallel output-series (IPOS) subsystem to step up the DC link voltage, and an input-series output-parallel (ISOP) subsystem to step down the output voltage. The two systems are connected through a transmission line. The challenge of the delay caused by the communication in the control system is addressed by introducing a ring communication structure, and its influence on the control system is analyzed to ensure the feasibility and required performance of the converter system under practical circumstances. Simulation and experiment results are presented to verify the effectiveness of the proposed design.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.479-480
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• 2007

This paper reports the results of time-domain simulation for the KEPCO metropolitan system with a secondary voltage regulation (SVR) model, developed with TSAT user defined model blocks. The previously proposed model in the literature needs switching blocks for converting level signals generated by a regional voltage regulator (RVR) into settings of reactive generation. This paper modified the SVR model not to incorporate the switching blocks, so it is much easier to implement the modified model on the simulation tool.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.2
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• pp.106-117
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• 2022

Multiple output converters can be utilized when various output voltages are required in applications. Recently, one of the multiple output converters called fly-buck has been proposed, and has attracted attention due to the advantage that multiple output can be easily obtained with a simple structure. When constant on-time (COT) control is applied, the output ripple voltage must be treated carefully for control stability and voltage regulation characteristics in consideration of the inherent energy transfer characteristics of the fly-buck converter. This study analyzes the operation principle of the fly-buck converter with a ripple generation network and presents the design guideline for the improved output voltage regulation. Validity of the analysis and design guideline is verified using a 5 W prototype of the COT controlled fly-buck converter with a ripple generation network for telecommunication auxiliary power supply.