• Journal of Power Electronics
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• 제15권5호
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• pp.1235-1243
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• 2015

This paper presents a modified Space Vector Pulse Width Modulation Technique (SVPWM), which solves the well-known problem of voltage imbalance in the capacitors of a single-phase multilevel inverter. The proposed solution is based on the measurement of DC voltage levels at each capacitor of the inverter DC bus. The measurements are then used to adjust the size of the active vectors within the SVPWM algorithm to keep the voltage waveform sinusoidal regardless of any voltage imbalance on the DC link capacitors. When a voltage deviation exceeds a predetermined hysteresis band, the correspondent voltage vector is restricted to restore the voltage level to an acceptable threshold. Hence, the need for external voltage regulators for the voltage capacitors is eliminated. The functionality of the proposed algorithm is successfully demonstrated through simulations and experiments on a grid tied application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.309-311
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• 1996

In this paper, we propose two types of novel discrete time current control methods of modified fixed band hysteresis control and optimal control for Parallel Resonant DC Link Inverters(PRDCLI). Because zero bus voltage intervals are generated on the DC link of PRDCLI, we can obtain the information of counter electromotive force(emf) by a simple estimation strategy. The proposed current controllers predict the currents of the next resonant cycle using the obstained information of counter emf and the average values of DC link voltages. The computer simulation results for a simple equivalent circuit of induction motor show that the proposed control methods are more effective than conventional methods.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.443-448
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• 2005

This paper proposed a regeneration inverter system, which can regenerate the excessive power form dc bus line to ac source for traction system. The proposed regeneration inverter system for dc traction can reduce harmonics which are include to ac current source. The regenerative inverter is operated as two modes. As a regeneration inverter mode, it can recycle regenerative energy caused by decelerating tractions and as an active power filter mode, it can compensate for harmonic distortion produced by the rectifier substation. In the paper, a regeneration inverter used PWM DC/AC converter algorithm. And an active power filter used p-q theory. The simulation was composed as a prototype model[3kW]. Simulation results show that two algorithm can be used to real model[100kW]. Finally, the inverter was successfully operated as regeneration mode.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.215-215
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• 2011

본 논문은 상용차용 전동 쿨링팬 모듈의 개발을 위한 5kW급 브러시리스 DC 전동기에 관하여 기술한다. 개발 대상전동기는 정격 3,000rpm의 회전속도를 목표로, 기존 팬 쉬라우드에 장착 가능한 박형으로 설계되며, 코깅토크 저감을 위한 회전자와 고정자 형상 최적화를 수행하여, 구동시 소음과 진동을 감소시키고자 하였다. 전동기를 제작하여 입출력 특성을 분석하고, 최종적으로 기 개발된 팬 블레이드와 결합하여, 쿨링팬 시스템의 유량 및 유압 특성시험을 진행하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.439-442
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• 2004

This paper described a dc power system, which can generate the excessive do power form do bus line to ac source in substation for traction system. The proposed regeneration inverter system for dc traction can be used as both an inverter and an active power filter(APF). As a regeneration inverter mode, it can recycle regenerative energy caused by decelerating tractions and as an active power filter mode, it can compensate for harmonic distortion produced by the rectifier substation.

• 전력전자학회논문지
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• 제12권5호
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• pp.372-377
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• 2007

본 논문은 가변속 구동 장치에서 직류링크 전압 평활용으로 사용되는 전해 커패시터의 새로운 고장 진단 방법을 제안한다. 전해 커패시터의 등가직렬저항은 직류링크 전압과 부하 전류로부터 직접 추정되고, 추정된 등가직렬저항으로부터 전해 커패시터의 상태가 결정된다. 온도 변동에 따른 등가직렬저항 변동을 보상하기 위해, 커패시터 주변의 PCB에 다이오드를 부착하고 다이오드의 전압 강하로부터 커패시터의 온도를 간접적으로 검출한다. 시뮬레이션 및 실험은 제안된 방식의 효용성을 보인다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.285-287
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• 2006

플라이휠 에너지 저장장치는 회전하는 물체에 에너지를 저장하고 이 에너지를 필요 시 기계적인 에너지를 변환하여 전기적 축전지이다. 플라이휠은 무정전전원장치의 직류측의 단자에서 전원을 받아 충전되며, 무정전전원장치의 입력 AC전압이 차단되어 UPS DC bus전압이 설정 값 이하로 떨어지면 저장 되어 있는 에너지를 전력변환 모듈에 의해 DC로 변환하여 UPS에 공급한다. 또한 전압 Sag, 전압의 불평형, 순간정전 및 고조파에 의한 정전에 대비하여 축전지와 플라이휠 에너지 저장장치를 조합하여 운용할 경우 축전지와 UPS의 DC BUS가 전기적으로 절연이 되어 개별 축전지 구성과 동일한 동작이 되도록 구성으로 축전지의 방전 횟수를 감소함으로써 축전지의 수명도 연장 할 수 있습니다.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.620-630
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• 2018

In this paper, a positioning method of distributed power system is proposed to minimize the average voltage variation of a DC microgrid through voltage sensitivity analysis. The voltage sensitivity under a droop control depends on the position of the distributed power system. In order to acquire a precise voltage sensitivity under a droop control, we analyzed the power flow by introducing a droop bus with the considerations of the droop characteristics. The results of the positioning method are verified through PSCAD/EMTDC simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.463-465
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• 2005

This paper proposes a regeneration inverter system, which can regenerate the excessive power form the DC bus line to the AC source for traction systems. The proposed regeneration inverter system for DC traction can reduce harmonics which is a characteristic of the AC current source. The simulation was composed as a prototype model[3.7kW]. Finally, it is shown that the inverter can successfully operate in regeneration mode.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.376-377
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• 2018

A hardware-in-the-loop (HIL) platform for a power management control of islanded DC microgrids is established. In order to avoid the complexity and high costs, a decentralized control based on the DC Bus Signaling (DBS) method is applied to the HIL system. The simulation results for the HIL microgrid platform have verified the effectiveness of power management strategy.