• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.283-284
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• 2011

Generally, it is important to use the regenerative energy efficiently for decrease of inverter's consuming energy. From various industry sector (railroad, steel, crane etc), re-uses the regenerative energy which uses the regenerative converter unit, and gets a many profit from whole consuming energy. In this paper, we introduce development of the regenerative converter unit that supply the regenerative energy to power source and main drive inverter, and introduce the instance which is applied in the elevator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.420-422
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• 2005

This paper introduces a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.685-688
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• 2006

본 논문에서는 초전도에너지저장 시스템에 적합한 간략한 회로 구성과 높은 신뢰성을 가지는 단상 무정전 전원공급장치를 제안한다. 제안된 시스템은 공통암 방식을 적용하여 스위칭 소자수를 저감한다. Normal, Stored-energy, Bypass의 세 가지 동작 모드에 대하여 상세히 설명한다. 사용되는 스위칭 소자수를 저감시키거나 수동소자로 대체시킬 경우 제어가 복잡해지고 자유도를 감소키는 문제점이 있지만 고성능의 디지털 제어기를 통해 추가적인 부담 없이 해결할 수 있다. 제안된 시스템의 타당성 검증을 위해 시뮬레이션 결과를 제시한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.110-115
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• 2014

The nuclear power plant was launched by Kori unit 1 in 1978 years. Currently, 23 nuclear power plants have been operating in Korea since 1978 years. The localization was completed for most of the reactor facility from Hanbit(Youngkwang) unit 3&4. However, RCP(Reactor Coolant Pump) and MMIS(Man Machine Interface System) is an important technology that has been excluded from the scope of the technical transfer has been dependent on a specific overseas vendor. Recent success in RCP development through co-operation with government and industries. Developed RCP will be applied to Shin-Hanul unit 1&2 nuclear power plants. The RCP operates in high speed and high pressure condition and only rotating component in the NSSS(Nuclear Steam Supply System). Therefore, the problem of vibration has arisen caused by the hydraulic forces of the working fluid. These forces can influence on the stability characteristics for entire RCS(Reactor Coolant System) loop, and can act as significant destabilizing forces. In this study, vibration evaluation of the pump shaft of development RCP estimated under normal operation and over speed conditions. In order to predict the vibration characteristics and dynamic behavior, modal analysis, critical speed analysis and unbalance response spectrum analysis were performed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.493-496
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• 2005

The PMU (Payload Management Unit) in MSC (Multi-Spectral Camera) is the main subsystem for the management, control and power supply of the MSC payload operation. The PMU shall handle the communication with the BUS (Spacecraft) OBC (On Board Computer) for the command, the telemetry and the communications with the various MSC units. The PMU will perform that distributes power to the various MSC units, collects the telemetry reports from MSC units, performs thermal control of the EOS (Electro-Optical Subsystem), performs the NUC (Non-Uniformity Correction) function of the raw imagery data, and rearranges the pixel data and output it to the DCSU (Data Compression and Storage Unit). The BUS provides high voltage to the MSC. The PMU is connected to primary and redundant BUS power and distributes the high unregulated primary voltages for all MSC sub-units. The PSM (Power Supply Module) is an assembly in the PMU implements the interface between several channels on the input. The bus switches are used to prevent a single point system failure. Such a failure could need the PSS (Power Supply System) requirement to combine the two PSM boards' bus outputs in a wired-OR configuration. In such a configuration if one of the boards' output gets shorted to ground then the entire bus could fail thereby causing the entire MSC to fail. To prevent such a short from pulling down the system, the switch could be opened and disconnect the short from the bus. This switch operation is controlled by the BUS.

• Journal of Power Electronics
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• 제19권1호
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• pp.234-243
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• 2019

Studying the control strategy of a microgrid under the load unbalanced state helps to improve the stability of the system. The magnitude of the power fluctuation, which occurs between the power supply and the load, is generated in a microgrid under the load unbalanced state is called negative sequence reactive power $Q^-$. Traditional power distribution methods such as P-f, Q-E droop control can only distribute power with positive sequence current information. However, they have no effect on $Q^-$ with negative sequence current information. In this paper, a stationary-frame control method for power sharing and voltage unbalance compensation in islanded microgrids is proposed. This method is based on the proper output impedance control of distributed generation unit (DG unit) interface converters. The control system of a DG unit mainly consists of an active-power-frequency and reactive-power-voltage droop controller, an output impedance controller, and voltage and current controllers. The proposed method allows for the sharing of imbalance current among the DG unit and it can compensate voltage unbalance at the same time. The design approach of the control system is discussed in detail. Simulation and experimental results are presented. These results demonstrate that the proposed method is effective in the compensation of voltage unbalance and the power distribution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.351-353
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• 2006

Preventive maintenance can avail the generating unit to reduce cost and gain more profit in a competitive supply-side power market. so, it is necessary to perform reliability analysis on the systems in which reliability is essential. In this paper, FMECA assessment adopted using real historical failure data in Korean power plants for apply RCM analytical method. The stochastic FMECA is an engineering analysis and a core activity performed by reliability engineers to review the effects of probable failure modes of generating unit and assemblies of the power system on system performance. Optimal RCM schedule which is considered the severity level of each generating unit and failure probability from failure prediction of generating unit can be planned using proposed FMECA with IOE index.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.309-311
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• 1995

Recently, a power supply system of the telecommunication equipments with monitoring function has been widely studied. In the power supply system which is apart from the central station, it is required to check and test the operating states of the system at the central station. In this paper, the power supply system with monitoring function is discussed. In the system, the Full-Bridge converter is designed as a power supply and it has the ratings of DC 280-340V input and DC 48V, 480W output. And the monitoring part of the system is composed of a voltage and current sensing unit A/D converter, I/O card, and a personal computer. The operating states of the system is monitored by checking the voltage and current variation at input and output, and it is represented by graphical modes. By conducting the experiment, it is confirmed that the operating states of the system is well monitored.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.220-223
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 EPS which is fully autonomous operation in normal conditions or in the event of a failure and provides a high level of reconfiguration capability and flexibility. This paper introduces the COMS EPS preliminary design result. The COMS EPS consists of a battery, a solar array wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SADM(Solar Array Drive Mechanism) and relay and fuse brackets. This can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type of solar cells is selected as GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated with battery and solar array generates a power bus fully regulated 50 V. Power bus is centralised protection and distribution by relay and fuse brackets. PRU provides power for firing actuators devices. The solar array wing is routed by the SADM under control of the AOCS(Attitude Orbit Control Subsystem). The control and monitoring of the EPS especially of the battery, is performed by the PSR in combination with on-board software.

• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.212-225
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• 2023

This study presents a modularized process of a hybrid renewable energy system that combines photovoltaic power and wind power to supply stable power in a unit area (1 km²). The water electrolysis process and fuel cells process also contributes to the supply of the stable power. The entire system can constantly supply power of 4.39 MW/km². Actual meteorological data is used for simulation.