• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.31-37
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• 2007

The generation cost of photo voltaic is the most expensive among the renewable energy. To reduce the generation cost of photo voltaic, the proposed method added the regeneration power of elevator. Therefore we have the simulation results the proposed method is 60[%] higher than the previous photo voltaic generation for efficiency of generation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2175-2184
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• 2009

This paper describes operational analysis results of the DC micro-grid using detailed model of distributed generation. Detailed model of wind power generation, photo-voltaic generation, fuel-cell generation was implemented with the user-defined model of PSCAD/EMTDC software that is coded with C-language. The operation analysis was carried out using PSCAD/EMTDC software, in which the power circuit is implemented by built-in model and the controller is modelled by user-defined model that is also coded with C-language. Various simulation results confirm that the DC micro-grid can operate without any problem in both the interconnected mode and the islanded mode. The operation analysis result confirms that the DC micro-grid make it feasible to provide power to the load stably. And it can be utilize to develop the actual system design and building.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1682-1687
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• 2016

Approximately 520thousand elevators are operating now in Korea, about 40% ~ 60% of the elevator power is generated. In this paper, by using the method of adding regeneration power of the elevator to the grid-tied photo voltaic inverter, PV generation that was dependant on the solar radiation was significantly improved. In order to confirm this, the regeneration power of the elevator has been simulated in 12% of the rating load, and measured the regeneration power of the elevator in the actual condition to assess the differences of it. The 5[kW] hybrid grid-tied photo voltaic invertor has been fabricated to conduct an experiment for the confirmation of the proposing method. The effectiveness of the proposing method has been reassured with the result of experiment that include the transfer interface part of the regeneration power of the elevator.

• Journal of Power Electronics
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• v.11 no.3
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• pp.350-359
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• 2011

This paper describes the operational analysis results of a DC micro-grid using a detailed model of distributed generation. A detailed model of wind power generation, photo-voltaic generation and fuel cell generation was implemented with an userdefined model created with PSCAD/EMTDC software and coded in C-language. The operational analysis was carried out using PSCAD/EMTDC software, in which the power circuit is implemented by a built-in model and the controller is modeled by an user-defined model that is also coded in C-language. Various simulation results confirm that a DC micro-grid can operate without any problems in both the grid-tied mode and in the islanded mode. The operational analysis results confirm that the DC micro-grid makes it feasible to provide power to the load stably. It can also be utilized to develop an actual system design.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.106-112
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• 2014

This paper presents the analysis of connected operation of photo voltaic source and Li energy storage system. The micro-grid has been installed and operated for several years at the campus of USF and has been a role of test bed. Photo voltaic source has been strongly influenced by the location, weather and climate of a installed area and Li battery is connected directly to the photo voltaic source to compensate for the limitations. The Li battery is operated to supply power output to the grid by the charging or discharging mode based on the average power output of the PV source which is calculated from monitored data for several years. The load of the PV and Li battery system is operated as a severe loading condition and the operating characteristics of PV source and Li battery are analyzed in detail. In connected operations of PV and Li battery to power system, the PV and Li battery is operated to supply constant power during only day time or peak time to increase load shedding ratio and efficient usage of generation sources in power system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.393-398
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• 2015

City or Community-scale Energy Management System(CEMS) is used to reduce the total energy consumed in the city by arranging the energy resources efficiently at the planning stage and controlling them economically at the operating stage. Of the operational functions of the CEMS, generation forecasting of renewable energy resources is an essential feature for the effective supply scheduling. This is because it can develop daily operating schedules of controllable generators in the city (e.g. diesel turbine, micro-gas turbine, ESS, CHP and so on) in order to minimize the inflow of the external power supply system, considering the amount of power generated by the uncontrollable renewable energy resources. This paper is written to introduce numerical models for photo-voltaic power generation prediction based on the weather forecasting information. Unlike the conventional methods using the average radiation or average utilization rate, the proposed models are developed for CEMS applications using the realtime weather forecast information provided by the National Weather Service.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.8
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• pp.599-604
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• 2012

Most air pollution and smog are a result of the burning of fossil fuels. The use of fossil fuels also causes acid rain and global warming. So the need for solar energy utilization is increased. It is essentially important to make efforts to reduce usage of fossil energy resources. In this study, we analyzed the correlation between climatic elements(Cloud cover, Duration of sunshine, Temperature) and the photovoltaic power generation. Cloud cover of the correlation coefficient was 0.87. And duration of sunshine of the correlation coefficient was 0.93. The order of the correlation coefficient was duration of sunshine, cloud cover, temperature. To accurately analyze of the degree of correlation for the photovoltaic power generation, additional research about climatic elements that show a high correlation is needed.

• Journal of the Korean Solar Energy Society
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• v.32 no.1
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• pp.8-14
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• 2012

Concerning about global warming due to emission of greenhouse effect gas like C02 and depletion of fossil fuels have been spreading. So the need for solar energy utilization is increased. It is essentially important to make efforts to reduce usage of fossil energy resources. In this study, we analyzed the correlation between climatic elements and the photovoltaic power generation. Cloud cover of the correlation coefficient was 0.93. The order of the correlation coefficient was average temperatures, hours of sunshine duration of sunshine and the humidity. To accurately analyze of the degree of correlation for the photovoltaic power generation, additional research about climatic elements that show a high correlation is needed.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.416-423
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• 2020

Majority of over 100 kW capacity photo voltaic (PV) power generation system was constructed on the plate ground of soil. Rarely PV system installed on concrete or building but it usually be under 25 kW capacity. On the soil ground the weeds growen up and it's shadow influenced to decrease of amount of PV power generation. This work analysis the weeds shadow's effect to decrease of PV power generation with 100 kW capacity of real PV power generation system in Yeungnam University, Finally the weed shadow"s influence value through the real field monitoring Data is suggested for give a standard management time of weeds to avoid the negative influence on whole power plant. Moreover the hot spot which is generated by long term partial shallow on PV module also can detected with the result of this work. It also suggested as a standard value of monitoring Data.

• Journal of Power Electronics
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• v.10 no.1
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• pp.79-84
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• 2010

This paper presents a grid connected photo-voltaic system using a quasi-Z-source inverter (QZSI) for power stage reduction. The power stage can be reduced because of an additional shoot-through stage which is a characteristic of QZSI. Therefore, by utilizing a QZSI the system's efficiency can be increased. In this paper, for applying a QZSI to a PV system, control methods such as maximum power point tracking (MPPT), point of common coupling (PCC) current control and PWM are studied and verified through simulation and experiment. In order to explain the above controllers, the characteristics of a QZSI are first analyzed. Then the MPPT control technique with a modified P&O method, the PCC current control for the regulation of the dc-link capacitor voltage and the PWM methods for the proposed system are explained. The feasibility of the proposed algorithm is verified through simulation and experiment with a 3kW system.