• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.56-69
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• 2021

In this paper, the PV system with a link to the commercial system needs some advantages like small capacity, high power factor, high reliability, low harmonic output, maximum power operation of solar cell, and low cost, etc. as well as the properties of inverter. To transfer the PV energy of photovoltaic power generation system to the system and load, it requires PCS in both directions. The purpose of this paper is to confirm the stable power supply through the load leveling by presenting the PCS considering ESS of photovoltaic power generation. In order to achieve these purpose, 5 step process of operation mode algorithm were used according to the solar insolation amount and load capacity and the controller for charging/ discharging control was designed. For bidirectional and effective energy transfer, the bidirectional converter and battery at DC-link stage were connected and the DC-link voltage and inverter output voltage through the interactive inverter were controlled. In order to prove the validity of the suggested system, the simulation using PSIM was performed and were reviewed for its validity and stability. The 3[kW] PCS was manufactured and its test was conducted in order to check this situation. In addition, the system characteristics suggested through the test results was verified and the PCS system presented in this study was excellent and stronger than that of before system.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.25-26
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• 2010

본 논문은 전기자동차용 인버터의 DC-Link 전압 가변을 위한 2상 양방향 DC-DC 컨버터의 제어 기법을 제안한다. 제안된 DC-DC 컨버터는 2-스위치 Buck-Boost 컨버터를 병렬구성 하여 전기자동차의 높은 출력에 대응하였으며 출력단 다이오드를 스위치로 교체하여 회생동작을 가능하게 하였다. 이를 시뮬레이션을 통하여 제어알고리즘의 가능성을 확인하였다.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.93-94
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• 2015

본 논문에서는 전기자동차 응용을 위한 양방향 전류원 인버터를 제안한다. 본 논문에서는 회로 DQ변환에 의하여 얻어진 DC 등가회로를 바탕으로 3상 시스템의 DC 특성을 보이고 직류측 전류, 전압과 같은 변수에 대한 식을 유도한다. 본 논문에서는 시뮬레이션을 통하여 제안된 양방향 전류원 인버터가 전기자동차 응용에 적합하게 사용될 수 있음을 확인한다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.159-160
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• 2016

본 논문은 계통 연계용 2레벨 인버터와 3레벨 인버터의 전력반도체 소자와 출력 필터에서 발생하는 손실을 비교 분석한다. 각 인버터 토폴로지 별로 국제 고조파 기준을 만족하도록 하는 출력 필터 설계 값을 고려하며, 각 인버터 토폴로지의 필터 설계 및 소자 선정 차이, 동작조건에 따른 손실 양상을 비교 분석한다.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.328-335
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• 1999

Three phase full bridge rectifier has been used to obtain dc voltage from three phase ac voltage source. The rectifier system has drawbacks that power factor is low and power flow is unidirectional. Therefore, when dc voltage increases due to regeneration of power the dynamic resister for dissipation of regeneration power must be installed. But three phase PWM converter can be controlled to operate with unity power factor and bidirectional power flow. Therefore when the PWM converter is used as do supply system, the dissipating resistor is not necessary. On this thesis, in order to design a controller having good performance, the hee phase PWM converter is completely modeled by using circuit DQ-transformation and thus a general and simple instructive equivalent circuit is obtained; the inductor set becomes a second order gyrator-coupled system and three phase inverter becomes a transformer as well. Under given phase angle(${\alpha}$) and modulation index(MI) of the three phase inverter, the dc and ac characteristics are obtained by analysis of the transformed equivalent circuit The validity of the equivalent circuit is confirmed through PSPICE simulation. And based on the dc and ac characteristics a controller with unity power factor is proposed.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.48-50
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• 2008

A wind power system with squirrel-cage induction generator has irregular change of output power according to the sudden change of wind speed. This paper describes the development of a active and reactive power compensator, which is composed of a 3-phase inverter and a bidirectional DC/DC converter with super-capacitor. The operational characteristic was analyzed through simulations with PSCAD/EMTDC and experimental works with a scaled model. The developed system can continuously compensate the active power change with energy storage and the reactive power change with 3-phase inverter.

• Journal of Electrical Engineering and information Science
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• v.1 no.1
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• pp.51-57
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• 1996

An improved predictive current control technique for a zero current switched(ZCS) buck-boost series resonant inverter(SRI) is proposed to overcome the inherent disadvantages such as the uncontrollable large overshoot and the large current ripple. Using the proposed technique, four quadrant operations of the output voltage and current for an uninterrutible power supply(URS) application are guaranteed and the buck-boost operation can also be obtained without an additional bidirectional switch.

• Journal of IKEEE
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• v.23 no.4
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• pp.1280-1287
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• 2019

Grid-connected bidirectional PCS(Power Conditioning System) technology is a technology for implementing distributed renewable energy smart grid. And it is always charged by using power collected from solar modules and commercial grid power among vast smart grid systems, and stored when needed.It is a hybrid energy storage device that allows power to be released into the low voltage system. To this end, a PV input power converter with MPPT function, a bidirectional power converter for battery charging and discharging, and a DC Link input are output to a 3 phase 380V AC system, and if nessary, the bidirectional DC/DC converter We designed and developed a PCS with three power converter structures composed of inverters that perform battery charging. Currently, this system is applied to the site of Jeju, which is vulnerable to power outages and fire accidents.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.2
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• pp.164-171
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• 2006

In this paper, the fault tolerant system for BLDC motor has been proposed to maintain control performance under an open switch fault of inverter. The fault identification is proposed to two methods, which are using the difference between reference and actual current, and adding voltage sensors across lower legs of inverter. The reconfiguration scheme is achieved by the four-switch topology connecting a faulty leg to the middle point of DC-link using bidirectional switches. The proposed fault tolerant system quickly recovers control performance by short fault detecting time and reconfiguration of system topology. Therefore, continuous free operation of the BLDC motor drive system after faults is available. The superior performance of the proposed fault tolerant system is proved by simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.1-8
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• 2007

This paper presents a new fault detection scheme for voltage fed inverter to improve the reliability of power electronic system, which is of paramount importance in the wide industrial applications. The proposed method is achieved by using voltage across lower switches in each phase under the switch fault condition. The reconfiguration method is achieved by the four-switch topology connecting a faulty leg to the middle point of DC-link using bidirectional switches. The proposed method has a simple algorithm and fast fault detection time. Therefore, normal operation of the system after faults is continuously achieved by reconfiguration of system topology. The superior performance of the proposed fault detection and tolerance method are proved by simulation.