• Journal of Power Electronics
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• 제15권4호
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• pp.920-928
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• 2015

Transformerless solar inverters have a higher efficiency than those with an isolation link. However, they suffer from a leakage current issue. This paper proposes a family of single phase six-switch transformerless inverter topologies with an ac bypass circuit to solve the leakage current problem. These circuits embed two unidirectional freewheeling current units into the midpoint of a full bridge inverter, to obtain a freewheeling current path, which separates the solar panel from the grid in the freewheeling state. The freewheeling current path contains significantly fewer devices and poor performance body diodes are not involved, leading to a higher efficiency. Meanwhile, it is not necessary to add a voltage balancing control method when compared with the half bridge inverter. Simulation and experiments are provided to validate the proposed topologies.

• International Journal of Computer Science & Network Security
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• 제22권5호
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• pp.1-4
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• 2022

The growth in global population and industrialization has led to an increasing demand for electricity. Accordingly, the electricity providers need to increase the electricity generation. Due to the economical and environmental concerns associated with the generation of electricity from fossil fuels. Alternative power recourses that can potentially mitigate the economical and environmental are of interest. Renewable energy resources are promising recourses that can participate in producing power. Among renewable power resources, solar energy is an abundant resource and is currently a field of research interest. Photovoltaic solar power is a promising renewable energy resource. The power output of PV systems is mainly affected by the solar irradiation and ambient temperature. this paper investigates the utilization of machine learning unsupervised neural network techniques that potentially improves the reliability of PV solar power systems during integration into the electrical grid.

• International Journal of Computer Science & Network Security
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• 제22권5호
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• pp.67-72
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• 2022

There has been a significant growth in global population and industrialization, as a consequence demand for electricity is increasing rapidly and the power systems need to increase the electricity generation. Currently, most of generated electricity is generated from fossil fuels. However, there are many financial and environmental concerns associated with the generation of electricity from such resource. Photovoltaic )PV) solar as a renewable resource is promising. The power output of PV systems is mainly affected by the solar irradiation and ambient temperature. This paper attempts at reducing the burden and improving the accuracy of the extensive simulations related to integrating PV systems into the electrical grid.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권1호
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• pp.88-92
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• 2014

This paper presents an application of a multiphase interleaved converter in tracking maximum power points (MPPs) of a photovoltaic (PV) panel regardless of environmental variations. Maximum power from the panel was extracted by means of the well-known the perturb-and-observe (P&O) method. The switching control technique used an interleaving scheme based on multi-unit synchronization. The converter performed harmonic attenuation without affecting the tracking speed. This approach is straightforward, reliable and inexpensive, and could be applied to any higher number of switching cells without difficulty.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.126-128
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• 2018

Solar array simulator (SAS) is a special DC power supply that regulates the output voltage or current to emulate characteristics of photovoltaic (PV) panels. Especially, the control of SAS is a challenging task due to the nonlinearity in the output curve, which is dependent on irradiance as well as temperature and is determined by panel materials. Conventionally, both current-mode control and voltage-mode control should be alternated by partitioning the operating curve into multiple sections, which is not only for the measurement noise problem with the feedback sensing but also for the control stability issue near the maximum power point. However, the occurrence of transition among different controllers may deteriorate the overall performance. To eliminate the mode transitions, a novel single controller scheme has been introduced in this paper, where the reference operating projection technique enables simple, smooth and numerically stable control. Theoretical consideration on the loop stability issue is discussed and the performance is verified experimentally for the emulation of a PV panel data in view of stability and response speed.

• 조명전기설비학회논문지
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• 제28권1호
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• pp.36-44
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• 2014

The conventional central photo voltaic inverters have several problems. First, shadow problem in each solar panel, and high DC voltage problem from each panel because of concentration to one central inverter. Therefore, module integrated inverter is proposed to solve these problems. The inverter should be small and cost effective. The cost and size in the inverter depend on the inductor. So the switching frequency should be increased to reduce the inductor and total size, but there is a problem in efficiency because of the losses in turn-on and turn-off. In the paper, the critical conduction mode(CRM) switching method is adopted to reduce the switching loss and interleaving method is proposed to increase the efficiency in Flyback converter. Finally, the validity of the proposed scheme is investigated with simulated and experimental results for a prototype system rated at 200W.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2011년도 제43차 동계학술발표논문집 19권1호
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• pp.299-300
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• 2011

태양에너지를 에너지 공급원으로 하고 LED 램프를 조명용 광원으로 사용하여 적은 전력 소모와 연장된 램프의 수명으로 에너지 소모를 크게 줄이고, 유지 보수 관리 비용을 획기적으로 줄일 수 있는 LED 조명제어시스템을 개발하였다. 점등 회로, 구동회로 등의 최적화된 설계와 구성으로 광 변환 효율을 높여 소형화, 경량화 되도록 하고, 환경 친화적인 조명 광원으로서 효율적인 성능을 얻을 수 있도록 한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.461-462
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• 2019

본 논문은 실제 차량 운행 조건에서 차량에 적용한 태양광 발전모듈의 발전특성을 분석하였다. 태양광 발전모듈 적용차량의 발전특성 분석을 위해 조도계 및 온도계를 이용한 실제 데이터를 활용하였으며, 차량 조건 및 온도 조건에 따라 발전 가능한 최대전력량을 도출하였다. 태양광 발전모듈에 대한 특성 데이터 및 태양광 발전모듈 적용차량의 실제 도로 운행 시 측정된 일사량 데이터를 통하여 태양광 발전모듈을 탑재한 차량의 발전특성을 연구하였다.

• 수산해양기술연구
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• 제50권4호
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• pp.487-494
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• 2014

This study describes the result on PV system for evaluating the performance of small fishing boats. Photovoltaic system with 200 watts power generation facilities on the 3-ton fishing boat was carried. Load test was performed on the condition that the work lamps lit during night operations. As a result the performance can be used for more than two hours at 60 watt work lamps. The load test was performed on the condition that fishing vessels are on the cruising condition at sea. The solar power systems have been investigated as a power generation efficiency of about 36.55%. Additional tests show that the power generation efficiency is difficult to expect a maximum of 50% or more. Fuel consumption of fishing boats by installing a solar power system is reduced. Also the PV system is useful for the verification of their availability for fishing vessels as well as the satisfaction of the fishermen. The results for the durability of the photovoltaic device is acceptable, including a solar panel, controller and the performance exhibited no breakage in the harsh marine environment or failure so far. The installed PV system was confirmed that the durability with at least 2 years.

• 한국산학기술학회논문지
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• 제11권8호
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• pp.2999-3004
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• 2010

LED는 다른 광원에 비해 동작수명이 길고, 친환경적이며, 에너지 효율이 높은 장점을 가지고 있다. 최근 LED 기술의 발전으로 인해 고휘도, 고용량의 LED가 개발됨에 따라, 표시장치에만 적용되던 LED를 조명장치에도 적용하는 기술이 확산되고 있다. 조명장치에 적용되는 파워 LED는 발열문제로 인한 소손을 막기 위해 구동전류를 일정한 전류값 이하로 제어할 필요성이 있다. 본 논문은 파워 LED의 구동전류를 설정된 값 이하로 제어하는 전류제 한 기능을 갖는 파워 LED 태양광 보안등 개발에 관한 연구이다. 태양광 발전에 의해 생산된 전력을 DC12[V] 축전지에 저장한 후, 야간에 승압형 DC-DC 컨버터를 통해 DC24[V]로 승압시켜 파워 LED로 공급한다. 태양광 보안등 제어기, 승압형 DC-DC 컨버터, 72[W]급 파워 LED 램프를 개발하여 동작을 확인하고 관련 데이터를 도출함으로써 제안된 시스템의 타당성을 입증하였다.