• 한국태양에너지학회 논문집
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• 제39권4호
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• pp.69-77
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• 2019

Among the main functions of the grid-connected photovoltaic (PV) system, the anti-islanding operation function is a very important problem. Recently, due to the improvement in power generation efficiency and the maintenance advantages in PV system, the use of string inverter has increased so that the possibility of islanding operation has been raised. Generally, when a power system faults, the PV inverter must be disconnected from power system within 10 cycles by the anti-islanding operation function. However, in the real-time of power system, the output power of the PV system within 10cycles is effected. In this paper, we analyzed the effect of grid-connected PV system on power quality in a short time within 10 cycles on fault case of power system using the Matlab Simulink program.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.477-482
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• 2021

Hydrogen production, hydrogen production cost, and utilization rate were calculated assuming four cases of hydrogen production system in combination of photovoltaic power generation (PV), water electrolysis system (WE), battery energy storage system (BESS), and power grid. In the case of using the PV and WE in direct connection, the smaller the capacity of the WE, the higher the capacity factor rate and the lower the hydrogen production cost. When PV and WE are directly connected, hydrogen production occurs intermittently according to time zones and seasons. In addition to the connection of PV and WE, if BESS and power grid connection are added, the capacity factor of WE can be 100%, and stable hydrogen production is possible. If BESS is additionally installed, hydrogen production cost increases due to increase in Capital Expenditures, and Operating Expenditure also increases slightly due to charging and discharging loss. Even in a hydrogen production system that connects PV and WE, linking with power grid is advantageous in terms of stable hydrogen production and improvement of capacity factor.

• 전기학회논문지
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• 제59권6호
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• pp.1046-1052
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• 2010

In residential house, photovoltaic (PV) system among various alternatives in renewable energy system is the most efficient and feasible solution for reducing energy consumption and electricity cost. However, relatively high initial cost make people reluctant to install PV system in their houses. Therefore, in the initial state for PV system installation in the house, it is very important to decide proper capacity of the PV system considering the expected energy usage and solar energy supplying condition with the house. This paper proposes a novel optimization model for deciding appropriate capacity of the PV system for residential house. The objective function of the model is to minimize the annual cost including electricity bill, operation and maintenance cost, and annual fixed cost calculated from the initial installation cost based on capital recovery factor (CRF). The model also shows the optimal inclining angle of PV panels of the system. In this paper, we estimate the PV output using PVWATTS (PV simulator of Office of Energy Efficiency and Renewable Energy) and find optimal solutions by Sequential Quadratic Programming (SQP) method using MATLAB software. The proposed approach is finally applied to a residential model house in Gangneung, Gangwon-Do and verified its feasibility for adopting to PV system design for residential houses.

• 전기학회논문지
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• 제56권1호
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• pp.8-13
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• 2007

During the last years, there has been an increased interest in the new energy such as photovoltaic(PV) system from the viewpoint of environmental pollution. In this regard, this paper estimates the power quality of grid-connected PV system. As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling that contains incremental conductance MPPT controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(TDD) and total demand distortion(TDD). For the case study, the measured data of the PV way in Cheongwadae, Seoul, Korea is used.

• 전기학회논문지
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• 제64권7호
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• pp.1012-1018
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• 2015

The studies on the operating performance analysis or design about the fixed tilt angle flat-plate photovoltaic (PV) system are still lively going off. However the operating property analysis about the arch type PV system which means PV array were designed as round type is dissatisfied. In this paper, we theoretically established the factors which are cause of the deterioration in performance of arch type PV system. In addition, we use the Solar Pro simulation tools to design both flat-plate type and arch type 30kW PV systems. The simulations about arch type PV system applied two ways such as central inverter and string inverter were conducted. The performance ratio (PR) of the PV system with flat-plate type shows the highest value 74[%] when the tilt angle is 30°. In case of arch type, when applying central inverter method, PR value shows approximately 73[%] and no more difference with arch type of the PV array. This value shows 1[%] decrease compare with the flat-plate type. However when applying string inverter methods, the average PR value shows 80 % and 6% improved than the central inverter method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권8호
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• pp.509-516
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• 2004

The concerns of distributed generations including photovoltaic(PV) system have been increased around the world since PV system is becoming widespread as a clean and gentle energy source for earth. In the future high density grid-connected PV systems will be interconnected with distribution network. As a result, the stability and long-term reliability of PV systems have become more important issues in this area. Grid-connected PV systems have been installed and monitored at field demonstration test center(FDTC) and also data acquisition system(DAS) has been constructed for measuring and analyzing performance of PV system to observe the overall effect of environmental conditions on their operation characteristics. The performance of PV system has been evaluated and analyzed for component perspective (PV array and power conditioning system) and global perspective (system efficiency, capacity factor, and electrical power energy) by field test and loss factors of PV system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.41-44
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• 2009

본 논문에서는 태양광발전이 본격적으로 보급 활성화 되기 전인 1999년 4월에 50 kVA 계통연계형 태양광 발전시스템 개발과제로 구축된 50kWp급 중규모의 계통연계 태양광 발전시스템의 약 10년간의 장기 실증운전을 통하여 취득한 자료를 기반으로 장기운전에 따른 운전특성 변화를 분석하였다. 본 설비는 50kVA급 PCS, 3kVA급 PCS 및 모듈 50kWp의 용량으로 1999년도에 한전 전력연구원 구내에서 실증시험용으로 구축되었으며, 장기운전에 따른 출력감소율은 10년간 전년도 대비 연 2.73% 이며, 발전설비 이용율은 11.04% 로 분석되었다

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.58-60
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• 2007

국내 신재생에너지의 보급은 정부 보조금 지원을 통해 국내 지역별로 다양한 형태, 발전 용량으로 보급되고 있다. 그 중에서도 태양광 발전의 주택보급과 산간지역의 풍력발전 보급은 발전 규모와 설비가 대형화 되어 가고 있다. 본 논문에서는 이러한 발전 시스템 지원을 위한 지역 기후 현황 분석과 발전 시스템과의 연계를 통해 특성을 분석하고자 하였다.

• 조명전기설비학회논문지
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• 제22권6호
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• pp.89-99
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• 2008

본 논문은 태양광 발전 추적 시스템의 발전량을 증가시키기 위해 일사량 급변에 대한 추적 장치 기동 시 전력소모를 고려한 새로운 추적 알고리즘을 제시한다. 종래의 태양광 발전에 사용되는 센서방식의 추적시스템은 구름 및 안개 등 급변하는 기후환경에 의해 추적 장치의 오동작의 문제점으로 태양의 정확한 추적이 불가능하다. 또한 프로그램 방식의 경우에는 기후 환경의 외부 요인에 대응하지 못함으로서 추적 장치의 불필요한 동작으로 인한 에너지소비가 발생된다. 이러한 이유로 태양 추적 장치가 실시간으로 태양의 방위각 및 고도 각을 추정하는 경우에도 실제 태양광 발전량은 특정한 위치에 고정되어 있는 경우보다 발전량이 증가하지 못한다. 본 논문에서는 이러한 전력소모를 줄이기 위한 추적시스템의 새로운 제어 알고리즘을 제시한다. 또한 종래의 태양광 추적 방식과 제시한 방법의 효율을 분석하고, 실증연구를 통하여 제시한 알고리즘의 타당성을 입증한다.

• 한국태양광발전학회지
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• 제4권1호
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• pp.42-55
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• 2018