• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.921_922
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• 2009

본 논문에서는 매트릭스 컨버터의 입력 필터를 설계하고 실험을 수행한 후 입력 파형 비교를 통하여 타당성을 검증하고 분석한다. 매트릭스 컨버터는 18개의 양방향 스위치로 구성되어 있으며, 출력 전압을 합성하기 위해 각각의 스위치가 실시간으로 빠르게 온-오프 한다. 이러한 스위칭 과정에서 고차 고조파가 발생하고, 이 고조파는 매트릭스 컨버터 주위에 연결된 각종 기기에 영향을 미친다. 이러한 영향을 줄이기 위해 설치한 것이 입력필터이다. 본 논문에서는 적절한 입력필터의 소자값을 계산해 내는 과정을 설명하고 이를 구현한 후, 실험을 통해 필터의 설치 전후의 입력 전류 고조파 왜곡율(THD) 등 파형의 변화를 비교하여 설계 값의 타당성과 필터의 적정성을 알아본다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2176_2177
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• 2009

This paper describe the power quality measuring result of the inter-connected residental PV system. The power quality measuring for inter-connected residental PV system are important to verify their performance and effect of power distribution system with inter-connected residental PV system. Also, these power quality measuring and analysis are essential to improve electrical safety. In order to evaluate influence of power distribution system with inter-connected residental PV system, we measure and analyze power quality index such as power, voltage, current, harmonic, THD, flicker index, power factor and frequency using DEWE5000.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2225_2226
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• 2009

An increasing of non-linear loads such as power electronic equipment in distribution systems is the reason for the greater concern about harmonics in recent time. A harmonic current and voltage in distribution systems can cause many problems such as malfunction of protective equipment. In this paper, Total Harmonic Distortion(THD) of voltage according to magnitudes and measurement locations of the non-linear loads was calculated and analyzed with Electro-Magnetic Transients Program(EMTP).

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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• pp.125-130
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• 2014

This paper is research result for a development of solar cell silicon ingot glowing(SCSIG) PWM converter system for 120[kW] 3[kA]. The system include 3-phase AC-DC rectifier diode converter of input voltage AC 460[V] and 60[Hz], DC-AC single phase full bridge PWM inverter of high frequency, AC-DC single-phase full wave rectifier using center-tapped of transformer for low voltage 50[V] and large current 3,000[A], carbon resistor load 0.2 [$m{\Omega}$]. PWM switching frequency for IGBT inverter control set 15KHz. The suggested researching contents are designed data sheets of power converter system, PSIM simulation, operating characteristics and analysis results of developed SCSIG system.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1234-1242
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• 2013

To verify the effectiveness of the proposed system, the charges in power demand are analyzed for an AC and DC distribution system for the existing V2G concept and electric vehicle charging stations connected to a Battery Energy Storage System. In addition, since many power-converter-based chargers are operated simultaneously in an EV charging station, the change in the system harmonics when several EV chargers are connected at a single point is analyzed through simulations.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.8
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• pp.441-448
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• 2002

Harmonics studies have been an important aspect of power conversion system analysis and design in recent years. Harmonics using power conversion device, have a harmful effect on power qualify. Nonlinear load such as converter causes harmonic and effects self & other system. There are linear and nonlinear loads in the end-user application. For filter design to reduce harmonics, it is important to understand how loads interact with each other. In this paper, effects on the power conversion system at the low voltage local bus are discussed.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.147-148
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• 2006

Recently, due to increasing the application of power electronic equipment, harmonics generated from the non-liner load are fairly produced. Harmonics can cause a variety of problems such as the overheating of distribution transformer, the breakdown of device and communication interference. Interest about power quality decline of power system is very increased. In this paper, we are measured the harmonic voltage and current o( power system to analyze harmonic characteristics, and it is analyzed Total Harmonic Distortion(THD). Also, we Ere modeled power system using PSCAD/EMTDC. And it is analyzed harmonic voltage and current in steady-state. The study results have been indicated the utility about harmonics analysis and modelling for power system.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.121-122
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• 2014

멀티 레벨 인버터는 높은 출력 전압을 갖으며, 낮은 THD(Total harmonic distortion)를 요구하는 시스템에 적합하다. 그 중 cascaded H-brige 멀티레벨 인버터는 H-bridge 셀별 관리가 쉽고, 레벨 수를 증가시키기 쉽다는 장점 때문에 많이 이용되어 왔다. 본 논문에서는 cascaded H-bridge 인버터의 기존 PI (proportional integral) 제어 기반 PWM (pulse width modulation)기법의 스위칭 패턴과 모델 예측 제어의 스위칭 패턴을 비교하고 모델예측 제어 시 셀 별 스위칭 패턴 균형을 위한 방법을 제안한다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.119-120
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• 2014

멀티레벨 인버터는 낮은 고조파 성분을 갖고, 제한된 정격 스위칭 소자로 대용량 전력변환이 요구되는 시스템에 매우 효율적이다. 수학적인 해석방법을 통해 전도손실, 스위칭 손실, 출력 전압 전류의 THD의 해석방법을 제시하고 시뮬레이션을 통해 멀티레벨 인버터의 특성을 비교 분석을 한다. 본 논문은 기존 제안된 멀티레벨 구조인 NPC(Neutral Point Clamped) 멀티레벨 인버터, Cascaded H-bridge 멀티레벨 인버터, Flying capacitor 멀티레벨인버터를 기반으로 25MW급 대용량 인버터의 손실 및 출력특성을 비교 분석하였다.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.2
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• pp.85-90
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• 2012

This paper presents a topology structure and control method for an input-parallel-output-series(IPOS) inverter system which is suitable for high input current, high output voltage, and high power applications. In order to ensure the normal operation of the IPOS inverter system, the control method should achieve input current sharing(ICS) and output voltage sharing(OVS) among constituent modules. Through the analysis in this paper, ICS is automatically achieved as long as OVS is controlled. The IPOS inverter system is controlled by a three-loop control system which is composed of an outer common-output voltage loop, inner current loops and voltage sharing loops. Simulation results show that this control strategy can achieve low total harmonic distortion(THD) in the system output voltage, fast dynamic response, and good output voltage sharing performance.