• Journal of Advanced Marine Engineering and Technology
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• 제33권6호
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• pp.939-945
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• 2009

This paper is described BLDC motor in the submarine propulsion system which is asked high power per unit area. This study analyzes the independent 6-phase BLDC motor a specific extended by existing the independent 3-phase BLDC motor and propose forward development direction. Independent 6-phase motor has a characteristics that phases of stator are independent electrically with each other and two's independence 3-phase BLDC motor are linked with each difference of 60 degree. Six-phase BLDC motor is simulated with Matlab-simulink, the simulation result has a high current and low torque pulsation than existent independence 3-phase BLDC motor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.138-142
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• 1998

This paper has been analyzed, modeled, designed, fabricated, and tested for solar cell simulator which has solar array characteristics. The main purpose is the development of solar cell simulator to test electrical power subsystem for GEO Communication Spacecraft. The maximum power of the simulator is about 5 ㎾, which is consist of 12 independent simulator modules with 420 W power rating. The 12 simulator modules are independently controlled like as real solar array system.

• 전기학회논문지
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• 제65권1호
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• pp.31-39
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• 2016

Power system engineers use power systems solution programs such as PSS/E, DSATool, Power World simulators for power system analysis. In this reason, KEPCO has begun to develop independent power system program, KW-PSS(KEPCO World Power system Solution) since 2002 and KW-PSS ver2.0 development was completed in 2011. However, it did not have much better functions compared with other programs. Therefore, we focused on the development of the practical and specialized functions. Consequently, PAZ(Power system AnalyZer) ver3.0 has been developed and it realized a differentiation than previous version. In other words, previous version focused on the basic function of power system analysis, PAZ ver3.0 has implemented many automated functions for power system operators were driven maximize operational efficiency. The unique feature of the implementation is as follows : Automated check for exceeding the breaker capacity, Scheduled outage automation, Control-file wizard for various voltage stability analysis, Scenario-based multiple transient stability analysis and Auto calculation of transmission line impedance. As shown in these functions, Those functions provide to use power system analysis easily by automation and simplification for power system engineers. We will secure national expertise through PAZ ver3.0. In addition it will be able to gain competitive edge through the steady development in the world market.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.113-118
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• 2018

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1721-1728
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• 2019

The advanced node core code CORCA-3D is one of the independent developed codes of NPIC for the nuclear reactor core design. CORCA-3D code can calculate the few-group cross section, solve the 3D diffusion equations, consider the thermal-hydraulic feedback, reconstruct the pin-by-pin power. It has lots of functions such as changing core status calculation, critical searching, control rod value calculation, coefficient calculation and so on. The main theory and functions of CORCA-3D code are introduced and validated with a lot of reactor measured data and the SCIENCE system. Now, CORCA-3D code has been applied in ACP type reactor nuclear cores design.

• Journal of Power Electronics
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• 제16권6호
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• pp.2221-2230
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• 2016

Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 kW prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.686-687
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• 2011

In this paper, the method on calculating benefits of combined heat and power is introduced for standard evaluation in electrical power system. This paper calculates benefits about new national viewpoint and viewpoint of independent power producers and assesses benefits of combined heat and power in Korea and In Seoul national capital area. Benefit costs are composed of avoid cost of centralized generation, line upgrading adjustment, loss adjustment and electrical power trade cost per year in earlier study, in addition trade cost of CO2, construction cost of combined heat and power for accurate calculation. Benefit of combined heat and power is calculated by simulation results of real electrical power system.

• 한국정보전자통신기술학회논문지
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• 제13권6호
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• pp.590-596
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• 2020

상용전력망과 계통연계가 어려운 도서지역에서는 독립적인 마이크로그리드로 생산된 에너지를 효율적으로 관리할 수 있는 방법을 찾는 것은 매우 중요한 일이다. 본 논문에서는 태양광과 풍력의 하이브리드 모델을 적용한 소규모 마이크로그리드에서 생산된 전력을 전력계측기와 수집된 데이터의 응답속도 테스트를 거쳐 P2P전력거래를 위한 프로슈머관리시스템을 구현하였다. 마이크로그리드 프로슈머 관리시스템의 전력망은 Mesh구조로 이루어져 있으며 P2P전력거래는 3곳의 독립적으로 구축된 off-grid 사이트에서 전력계측기와 DC전력전송기를 이용하여 테스트하였고, 이때 전력계측기의 측정값은 전압(평균값) : 380V + 0.9V, 전류(평균값) : + 0.01A, 전력 : 1000W ( - 1W)로 오차 허용범위인 ±1%이내로 나타나 그 유의성을 확인하였다. 실시간으로 50개의 데이터를 동시 전송하여 메인화면 0.32초, 일 발전량 2.61초, 누적발전량 2.77초, 전력거래 0.11초 등의 응답속도가 나타나 서버의 안정화를 확인하였다. 따라서 본 시스템은 한국전력의 중계 없이 독립적인 망으로 활용될 수 있는 P2P 전력거래시스템으로서 그 타당성이 입증되었다.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1408-1414
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• 2015

The renewable energies such as photovoltaic power, wind power and biomass have grown to a greater extent as decarbonization techniques. The renewable energies are interconnected to power systems (or electrical grids) in order to increase benefits from economies of scale, and the extra attention is focused on the Grid Code. A grid code defines technical parameters that power plants must meet to ensure functions of power systems, and the grid code determined by considering power system characteristics is various across the country. Some TSO (Transmission System Operator) and ISO (Independent System Operator) have issued grid code for wind power and the special requirements for offshore wind farm. The main purpose of the above grid code is that wind farm in power systems has to act as the existing power plants. Therefore wind farm developer and wind turbine manufacturer have great difficulty in grasping and meeting grid code requirements. This paper presents the basic understanding for grid codes of developed countries in the wind power and trends of those technical requirements. Moreover, in grid code viewpoint, the active power control of wind power is also discussed in details.

• Journal of Power Electronics
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• 제12권4호
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• pp.578-586
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• 2012

In this paper a single-phase Cascaded H-Bridge (CHB) inverter for photovoltaic (PV) applications is presented. Based on the presented mathematical analysis, a novel controller is introduced which adjusts the inverter power factor (PF) and manipulates the distribution of the reactive power between the cells to enhance the operating range of the CHB inverter. The adopted control strategy enables tracking of the maximum power point (MPP) of distinct PV strings and allows independent control of the dc-link voltages. The proposed controller also enables the inverter to operate under heavily unbalanced PV conditions. The performance of the CHB inverter and the proposed controllers are evaluated in the PSCAD/EMTDC environment. A seven-level CHB-based grid connected laboratory prototype is also utilized to verify the system performance.