• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.44-45
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• 2011

Research on photovoltaic (PV) generation is taking a lot of attention due to its infinity and environment-friendliness with decrease of price per PV cell. While central inverters connect group of PV modules to utility grid in which maximum power point tracking (MPPT) for each module is difficult, micro inverter is attached on each module so that MPPT for individual modules can be easily achieved. Moreover, energy generation and consumption efficiency can be much improved by employing direct current (DC) distribution system. In this paper, a digitally controlled PV micro converter interfacing PV to DC distribution system is proposed. Boundary conduction mode (BCM) is utilized to achieve zero voltage switching (ZVS) of active switch and eliminate reverse recovery problem of passive switch. A 120W prototype boost PV micro converter is implemented to verify the feasibility and experimental results show higher than 98% efficiency at peak power and 97.29% of European efficiency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1570-1575
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• 2018

The increased penetration of PV is impacting on grid operation and in particular the voltage within the local grid can be significantly influenced by the various PV systems. The increased penetration of PV is impacting on grid operation and in particular the voltage within the local grid can be significantly influenced by the various PV systems. This paper describes domestic technical standard of Photovoltaic(PV) PCS(Power Conditioning Systems)- Characteristics of the utility interface. Especially protective function test items of 1) Output overvoltage protection test, 2) Output undervoltage protection test, 3) Frequency rise protection test, 4) Frequency fall protection test, 5) System voltage's momentary interruptions, 6) System voltage distortion capability test. Therefore in this paper protective function test item of facilities evaluation detailed standards for new renewable energy, small, medium and large photovoltaic inverter standard is studied and analyzed and finally full tested by PV inverter performance function.

• Journal of the Korean Solar Energy Society
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• v.28 no.1
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• pp.1-8
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• 2008

The aim of this study is to develop the photovoltaic simulation program, called SimPV, which can Predict hourly based power generation of various PV modules and conduct an intensive economic analysis with Korean situation. To establish the reliability of the PV simulation results, we adopt the PV calculation algorithm of TRNSYS program of which verification has already well approved. Extensive database for hourly weather data of Korean 16 cities, engineering data for PV system and building load profiles are established. Case study on the 2.5kW roof integrated PV system and economic analysis are presented with the developed program.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1293-1302
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• 2014

A flyback inverter using voltage sensorless maximum power point tracking (MPPT) for photovoltaic (PV) AC modules is presented. PV AC modules for a power rating from 150 W to 300 W are generally required for their small size and low price because of the installation on the back side of PV modules. In the conventional MPPT technique for PV AC modules, sensors for detecting PV voltage and PV current are required to calculate the PV output power. However, system size and cost increase when the voltage sensor and current sensor are used because of the addition of the auxiliary circuit for the sensors. The proposed method uses only the current sensor to track the MPP point. Therefore, the proposed control method overcomes drawbacks of the conventional control method. Theoretical analysis, simulation, and experiment are performed to verify the proposed control method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.4
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• pp.168-172
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• 2007

The global environment deteriorating which originated from using of fossil fuel is an serious problem for human being to solve. The photovoltaic energy has been considered as a solution. In advanced countries, research and development for photovoltaic(PV) energy system is carrying on. Once installed, a PV array requires maintenance and fault diagnosis other than an occasional cleaning. In this research, the proposed system monitor and diagnosis the output of PV array by on-line for maintenance of PV power plant. The validity of proposed system is verified using sample system.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.311-313
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• 2007

Three phase power flow is commonly considered exclusively for the distribution systems, where single or double phase circuits may be present and loads may not always balanced between the three phases. This paper deals with modelling and analysis of grid connected photovoltaic (PV) system in three-phase power flow, with the consideration of the PV inverter output power limitations.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.123-126
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• 2005

Recently, because of the depletion of fossil fuels and the environmental pollution by using fossil fuels and harmfulness of atomic power plants. the interests concerning new and renewable energy resources are rising increasingly. And of all new and renewable energy sources the PV generation systems are recognized as the most useful and desirable renewable energy source in allowance for installation conditions. In this development, the 3kWp photovoltaic power generation system is realized to verify the performance of the 3kWp PCS developed by Hyundai Heavy Industries Co. (HHI). The photovoltaic array used in this system is composed of 60 modules of 50Wp capacity. The developed system is tested as procedures and items of test regulation recognized by governmen and the experimental results show the excellent electrical characteristics. Now, the 3kWp PCS developed is installed in the PV model house built in HHI plant and is being tested for practical use commercialization.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.355-363
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• 2007

In this paper, the transformerless three-phase line-connected PV PCS (photovoltaic power conditioning system) is proposed. An improved P&O (perturb and observe) MPPT (maximum power point tracking) algorithm that prevents local maximum power point tracking is proposed. By controlling the three-phase line-connected voltage source inverter using outer DC-link voltage controller, inner current controller and microcontroller friendly simplified space vector modulation (SVM) method, a unity power factor is achieved. An algorithm is suggested to control the DC-link voltage faster and more correctly for the increase system stability and power factor. All algorithms and controllers are implemented on a single-chip microcontroller and the superiority of the proposed algorithms and controllers is proved by experiments.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.341-343
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• 2006

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1205-1206
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• 2006

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.