• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.639-640
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• 2015

본 논문에서는 일간 시간대별 에너지저장장치 (Energy Storage System, ESS) 최적 충 방전량 스케줄링을 이용하여 계통연계형 마이크로그리드 내에 설치되는 ESS의 용량을 산정한다. 대상 마이크로그리드의 과거 부하데이터를 이용하여 절감하고자 하는 양을 정하고, 이를 이용하여 전력변환장치(Power Conditioning System, PCS)의 정격출력량을 산정한다. ESS용량의 기준점을 정하여 이분법 적용구간을 설정하고, 반복연산을 통해 최적 ESS용량을 찾는 과정을 제시한다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.986-987
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• 2015

본 논문은 이차전지 에너지저장장치(ESS)을 위한 충 방전용 5kW급 계통 연계형 PCS(Power Conditioning System) 구성 및 실험에 대하여 서술하였다. 양방향 계통 연계형 PCS는 4Phase 인터리브드 DC/DC컨버터, 단상 계통 연계형 인버터로 구성된다. 4Phase 인터리브드 DC/DC컨버터를 통해 배터리 리플전류를 감소시켰으며, 계통에 의해 DC_Link에 발생하는 리플전류를 저감할 수 있는 L-C공진회로를 설계하고 실험하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.505-506
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• 2015

분산전원의 보급이 증가함에 따라 계통에 연계되어 운전하는 분산전원들은 지역의 전력품질을 유지하는 역할이 요구될 것으로 예상되기 때문에 계통에 유효전력과 무효전력을 적절하게 공급할 수 있는 역률제어형 인버터에 대한 역할이 증가할 것으로 예상된다. 이에 따라 역률제어형 인버터를 설계하고 계통과 연계되어 운전될 때, 출력단에 연결되는 필터에 대해 고찰할 것이다. 제안하는 인버터의 알고리즘과 출력필터의 영향을 검증하기 위해 PSCAD/EMTDC 시뮬레이션 툴을 사용하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1064-1065
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• 2015

단상 계통 연계형 전력 변환기에서 계통과 연계하기 위해서는 계통의 위상 정보를 정확히 측정하여 전력 변환기의 출력 주파수와 위상이 동일한 상태로 전류가 공급 되도록 해야 한다. 본 논문에서는 단상 d-q 좌표 변환 기법을 통한 위상 동기화 기법을 적용하여 왜곡된 계통전압이 d축 전압에 야기 되는 에러 성분을 최소화 하는 보상 기법을 제안한다. 제안된 기법은 동기 d축 전압을 일정한 주기로 적분하여 에러 성분을 최소화 한 후, PI제어를 통해 d축 전압을 0으로 수렴하게 하는 기법이다. 제안된 기법은 추가적인 하드웨어를 요구하지 않는다. 본 논문의 타당성을 검증하기 위해 3[kW]급 단상 계통 연계형 전력변환기 시작품을 제작하고 실험을 통해 증명하였다.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.873-878
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• 2000

Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.529-531
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• 2006

The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. The main subject of this paper is about making the more useful real-time monitoring program to get and save the data from photovoltaic generation system of 30kW grid-connected. Therefore, it uses LabView for this real-time monitoring program.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.551-554
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• 2002

This paper describes a new interactive inverter between a photovoltaic(PV) array and single-phase utility that avoid the bulky input (60Hz) transformer on the AC side. The interface employs a pwm boost converter on the DC side followed by a pwm current-forced single-phase rectifier for injecting the power from the PV array into the mains. The current waveform at the AC side remains sinusoidal and exactly in phase at all time. The circuit also has the advantage of requiring fewer switching device than high-frequency link system. This paper describes modeling of PV array and new system topology. Simulation results on the performance of the connection are also presented.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.555-558
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• 2002

The general ways of the anti-islanding can be classified into the active method and passive method. The passive method which use only the voltage information when power failure occurs has much possibility of the wrong detection. And the active method detects the change of the voltage frequency as instantaneously changing the frequency of the inverter output current. Therefore, in this paper, the method to inject arbitrary order harmonics into controlled current is proposed. In this method islanding can be detected by measuring the amount of load voltage of injected harmonics order. And as a current control method predictive control method is used, which make actual current accurately to track reference current by Instantaneously computing converter output voltage and has fast response in transient state. This parer proposed method was verified by simulation.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.558-560
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• 2006

Solar cell converts sunlight into the electricity that one of the most versatile forms of energy. It has been developed and applied on residental electric power system by urbanized countries as a alternative energy source to overcome energy problem after oil shock. This paper summarizes the results of these efforts by offering a snapshot of the configuration of photovoltaic in residential applications. The status of PV system components and inter-connection and safety equipment will be summarized. Hence this paper discusses only points that might be useful for application.

• Journal of Power Electronics
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• v.16 no.2
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• pp.748-759
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• 2016

The microgrid concept is a promising approach for injecting clean, renewable, and reliable electricity into power systems. It can operate in both the grid-connected and the islanding mode. This paper addresses the two main challenges associated with the operation of a microgrid i.e. control and protection. A control strategy for inverter based distributed generation (DG) and an energy storage system (ESS) are proposed to control both the voltage and frequency during islanding operation. The protection scheme is proposed to protect the lines, DG and ESS. Further, the control scheme and the protection scheme are coordinated to avoid nuisance tripping of the DG, ESS and loads. The feasibility of the proposed method is verified by simulation and experimental results.