• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.314-316
• /
• 2008

계통연계형 태양광 PCS는 주로 전압원 인버터와 전압의 승압을 위한 DC/DC컨버터, 즉 이단구조로 구성된다. Z-소스 인버터는 DC/DC컨버터 없이 전압을 승/감압할 수 있다. 3k급 계통연계형 태양광 PCS에 Z-소스 인버터를 적용하여 일단구조로 설계하였고 PSIM 시뮬레이션과 실험을 통하여 타당성을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2018.07a
• /
• pp.348-349
• /
• 2018

본 논문은 DC Common 방식의 Hybrid PCS (Power Conditioning System)의 해외 실증사례에 대해 서술하고 있다. 본 시스템은 계통, PV(Photovoltaic), BESS (Battery Energy Storage System)로 구성되어 있으며 UAE의 Dubai에 60kW급 2기, 200kW급 1기를 실증한 사례를 설명한다. 각 구성품 들의 사양과 Destin Power사 Hybrid PCS를 소개하고 사양을 서술하였으며 실제 운영을 통하여 제품의 신뢰성을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2015.11a
• /
• pp.97-98
• /
• 2015

에너지 저장 시스템(ESS, Energy Storage System)은 태양광(PV)발전, 풍력(WT)발전시스템 등과 같은 신재생 에너지 출력안정화, 계통 전력품질 개선, 수용가 에너지효율화 등의 분야에 이용되고 있다. 에너지 저장 시스템은 전력변환장치와 에너지 저장 장치로 구성되며, 에너지 저장 장치로 배터리를 많이 사용하고 있다. 전력변환장치 및 제어기의 설계 및 검증을 위해서는 배터리를 전력변환장치에 연계하여야 하지만 배터리의 경우 고가에 관리가 어려운 문제로 인해 일반적으로 배터리 모의 장치를 이용한다. 본 논문에서는 대용량 에너지 저장 시스템용 전력변환장치 및 제어기의 설계와 현실적인 검증이 가능한 MW급 PCS 성능검증용 배터리 모의장치를 개발하였다.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.302-303
• /
• 2020

본 논문은 모듈 평가를 위한 태양광 PCS 개발과 이에 적용되는 모듈 성능 비교에 대해 다룬다. 개발되는 인버터는 3상 380V, 26.5kW 급으로 MNPC 타입의 전력반도체 모듈을 적용한다. 전력반도체 모듈 국내 개발품과 해외 선진사 제품(Vincotech사)의 성능비교를 위해 데이터시트를 기반으로 손실 분석을 수행하였다. 그리고 이를 검증하기 위해 개발된 전력모듈을 평가용 인버터에 적용하여 부하별 효율 비교 평가를 진행하였다.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.5
• /
• pp.1447-1453
• /
• 2014

This paper proposes the new method based on the availability of three points measurement and convexity of photovoltaic (PV) curve characteristic at the maximum power point (MPP). In general, the MPP tracking (MPPT) function is the important part of all PV systems due to their power-voltage (P-V) characteristics related with weather conditions. Then, the analog-to-digital converter (ADC) and low pass filter (LPF) are required to measure the voltage and current for MPPT by the digital controller, which is used to implement the PV power conditioning system (PCS). The measurement and quantization error due to rounding or truncation in ADC and the delay of LPF might degrade the reliability of MPPT. To overcome this limitation, the proposed method is proposed while improving the performances in both steady-state and dynamic responses based on the detailed investigation of its properties for availability and convexity. The performances of proposed method are evaluated with the several case studies by the PSCAD/EMTDC$^{(R)}$ simulation. Then, the experimental results are given to verify its feasibility in real-time.

• Journal of Power Electronics
• /
• v.12 no.3
• /
• pp.487-494
• /
• 2012

A new low cost high power density photovoltaic power conditioning system (PV PCS) with an energy storage system is proposed in this paper. Its high power density and cost effectiveness can be achieved through the unification of the maximum power point tracker and the battery charger/discharger. Despite the reduced power stage, the proposed system can achieve the same performance in terms of maximum power point tracking and battery charging/discharging as the conventional system. When a utility power failure happens, the proposed system cannot perform maximum power point tracking at the UPS mode. However, the predetermined battery voltage near the maximum power point of the PV array can effectively generate a reasonable PV power even at the UPS mode. Therefore, it features a simpler structure, less mass, lower cost, and fewer devices. Finally, to confirm the operation, validity, and features of the proposed system, a theoretical analysis and experimental results from a single phase AC 220Vrms/1.5kW prototype are presented.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1471-1473
• /
• 2004

Maximum power point tracking(MPPT) is used in photovoltaic(PV) systems to maximize the photovoltaic array output power, irrespective of the temperature and irradiation conditions. The object of this paper is to compare and analyze MPPT efficiency for different MPPT techniques by changing irradiance. Also, this paper introduces transformerless grid-connected inverter. Simple flow charts and characteristics of each MPPT algorithm are shown. The implementation of transformerless grid-connected inveter system was based on a digital signal processor(DSP). Simulation was carried out for each MPPT method.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.343-344
• /
• 2012

In high power PV generation system, the solar cell normally generates wide output voltage depending on the insolation, cell's temperature and shade effect. This paper will propose a high efficiency converter allowing the wide input voltage to supply stable voltage with the controller and operation for the PV generation system. The proposed converter consists of two stages comprising SEPIC with a coupled inductor and LLC, which generates 24 V of output at the final output terminal. In this paper, a design method and experimental results with a test-bed of 50 W will be presented to validate the proposed converter.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1781-1783
• /
• 2005

To evaluate the grid-connected Photovoltaic(PV) system performance, as a medium size, a 120 kW PV system which was consisted of solar cells, PCS, 150kVA transformer station and utility grid was designed and constructed.

• KEPCO Journal on Electric Power and Energy
• /
• v.5 no.1
• /
• pp.25-32
• /
• 2019

K-BEMS System was introduced to reduce peak load and to save total energy of the 200 buildings that KEPCO headquarter and branch offices use. And K-BEMS system is composed of PV, battery, and hybrid PCS. KEPCO research institute has carried out this K-BEMS research project for 3 years since January 2016. In this paper, the results of the project are shown. 9 modes of test results of K-BEMS system and are operational problems were analyzed. And measures to cure the trouble are also suggested. Batteries are operated more than 20% of SOC, and less than 20% of SOC battery protection switches are automatically shutting down the system and the system no longer respond to EMS, ending the supply of PV, and so therefore to continue the PV power supply it was turn out to be necessary that the EMS should automatically change its policy to change PV only supply mode automatically when the Battery Switch automatically operated. To operate the system continuously and automatically, it is necessary to modify the minimum operational SOC value, and in addition to that the EMS computer must remember the last shut-down SOC and Voltage which interrupted the system and add some margin to reflect the measurement error in the system.