• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.90-95
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• 2015

This paper describes IEC 61727 standard of Photovoltaic (PV) systems -Characteristics of the utility interface. IEC 61727 standard tests include utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1) voltage, current and frequency, 2) normal voltage operating range, 3) flicker, 4) DC injection, 5) normal frequency operating range, 6) harmonics and 7) waveform distortion, 8) power factor of PV inverter. Also personnel safety and equipment protection part includes test items 1)loss of utility voltage, 2)over/under voltage and frequency, 3)Islanding protection, 4)response to utility recovery, 5)earthing, 6)short circuit protection, 7)Isolation and switching of PV inverter. In this paper, each item of IEC 61727 standard test is studied and analyzed and finally full tested by PV inverter performance function.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.512-517
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• 2001

In this paper, a wide input range active multi-pulse rectifier for utility interface of power electronic converters is proposed. The scheme combines multi-pulse method using a V-A transformer and boost rectifier modules. A current control scheme for the rectifier modules is proposed to achieve sinusoidal line currents in the utility input over a wide input range of input voltage and output load conditions. A design example is included for a 208V to 460V input, $700V_{dc}$ do 10kW output rectifier system. Simulation results are shown.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1050-1052
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• 2000

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system (3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation. a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.139-148
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• 2005

This paper presents recent works of the development of MPEG-21 DIA utility software as one of MPEG-21 activities. The main purpose of this work is to make integrated utility software for DIA C/C++ modules in a Java framework. To do this, JNI plays a role of the interface of a main module with C/C++ DIA adaptation modules. Furthermore, DIA and DID parsers are integrated to the utility software. Our software is designed such that all DIA modules are easily integrated. A variety of adaptation modules have been adopted in MPEG-21 standard. Among them, stereoscopic video conversion that is one of DIA adaptation modules is chosen and we show that our utility software is correctly implemented based on experiments.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.6
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• pp.287-298
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• 2000

The UCA is a standard-based approach to utility communications which provides for wide scale integration of functional areas including customer interface, distribution, transmission, power plant, control center, and corporate information systems. Field devices in the power facilities require real-time communications, and they must be interconnected into fieldbus. This study introduces a method of implementing gateway that interfaces UCA and fieldbus. In this study, PROFIBUS and FOUNDATION Fieldbus are selected as candidate fieldbus protocols. Protocol interface in the gateway can be accomplished by mapping objects and services of UCA and fieldbus. MOst of the UCAs CASM objects and services are directly mapped into those of the application and user layers of fieldbus. However, some CASM services are not supported in the application and user layers of fieldbus. This study presents the method of implementing those services. In order to show that the implementation of interface is possible, this study presents pseudo-codes of interface program that maps the objects and services of UCA and fieldbus.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1281-1283
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors a net size, weight, and parts cost saying result compared to the other systems due to elimination of 60Hz transformer.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.467-469
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier, four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.46-49
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kVA) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kVA high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier. four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.2
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• pp.45-54
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• 1992

It become increasingly important to design user interface to carry low complexity. The cognitive limitations of users severely restrict utility of highly intelligent but complex modern systems. Since humans are known to use schemas to reduce cognitive complexity, imposing good consistency to an interface design that may help that user form useful schemas will provide powerful control over the complexity. This present a research effort to develop a quantitative method for evaluating interface complexity that the user would experience planning his or her course of action. Taking into account the user's potential schemas, a quantitative measure based on information theory was develped to assess the navigational complexity. This approach does not rely on the subjective judgment of the researcher as most schemes dealing with user schemas do. The proposed method may benefit the rapid prototyping approach to design a better user interface by allowing handy assessment of the design.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1221-1222
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• 2005

Interface control activities during the nuclear power plant (NPP) construction and operation have been reviewed for enhancing the safety of NPP. The primary focus of the study is given on analysis of lessons learned from the recent significant events of Korean Standard Nuclear Power plant (KSNP), such as a series of break-off of thermal sleeves at YGN 5 & 6 and radioactivity leak at YGN 5, in respect of interface control. Based on the results of the analysis, this study recommends measures for the improvement of interface control among utility and technical supporting organizations (TSO), and suggests new regulatory systems, such as reporting of safety significant non-conformances, to effectively verify the adequacy of interface control activities during construction and operation of NPPs.