• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.7
• /
• pp.57-66
• /
• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems

• Journal of Power System Engineering
• /
• v.5 no.3
• /
• pp.80-87
• /
• 2001

Decorative properties of chromium depositions from oxalic acid bath containing chromium oxide and ammonium sulfate have been examined over a wide range of bath compositions and plating conditions. The obtained results from this experiment are summarized as follow: The followings were determined as a optimum conditions, bath compositions; $CrO_3\;200{\sim}250\;g/{\ell},\;H_2C_2O_4{\cdot}2H_2O\;500{\sim}700\;g/{\ell},\;(NH_4)_2SO_4\;40{\sim}120\;g/{\ell}$, and operation conditions; pH $2.0{\sim}2.5$, current density $15{\sim}250\;A/dm^2$ at bath temperature range of $30{\sim}80^{\circ}C$. Bright chromium deposits were obtained over a wide range of ammonium sulfate concentration and bath temperature. Decorative property for chromium deposition was adopted to apply stoichiometric ratio of $CrO_3$ concentration and $H_2C_2O_4{\cdot}2H_2O$.

• Journal of Power System Engineering
• /
• v.5 no.1
• /
• pp.89-96
• /
• 2001

Decorative property of chromium deposition from oxalic acid bath containing chromium oxide and ammonium sulfate, has been examined over a wide range of bath compositions and plating conditions. The followings were determined as optimum bath composition, $CrO_3\;200{\sim}250g/{\ell},\;H_2C_2O_4{\cdot}2H_2O\;500{\sim}700g/{\ell},\;(NH_4){_2}SO_4\;40{\sim}120g/{\ell}$, and operation conditions; pH $2.0{\sim}2.5$, current density of $15{\sim}250Adm^2 $ at the bath temperatures of $30{\sim}80^{\circ}C$. Bright chromium deposits were obtained over a wide range of ammonium sulfate concentration, bath temperature, and current density. The current efficiency decreased with increasing current density and bath pH, and increased with Increasing bath temperature. The highest current efficiency was obtained in the bath containing $80g/{\ell}$ of ammonium sulfate. Bright chromium deposits were not obtained at conditions of all the highest current efficiencies.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1768-1769
• /
• 2003

가스절연개폐장치(Gas-insulated Switchgear, GIS)의 예방진단 기술의 한 방법으로, 극 초단파(Ultrahigh frequency) 부분방전(Partial discharge) 센서를 사용하여 결함의 유무를 판별할 수 있다. 그러나 UHF PD 센서에는 부분방전신호 이외에 외부 잡음의 유입 가능성이 크다. 따라서 본 논문에서는 PD 센서 주변 잡음을 측정하기 위하여 $0{\sim}2$ GHz 의주파수영역에서 산지, 도심 지역의 변전소의 위치에 따른 외부 잡음을 측정하였다. 주파수 대역별로 FM 방송, TV 방송, 이동전화, 등의 신호를 판별하였다.

• Journal of Power Electronics
• /
• v.11 no.4
• /
• pp.479-489
• /
• 2011

The bidirectional dc-dc converter, being the interface between Energy Storage Element (ESE) and DC bus, is an essential component of the power management system for vehicle applications including electric vehicle (EV), hybrid electric vehicle (HEV), and fuel cell vehicle (FCV). In this paper, a novel multiphase bidirectional dc-dc converter interfacing with battery to supply and absorb the electric energy in the FCV system was studied with the help of real time digital simulator (RTDS). The mathematical models of fuel cell, battery and dc-dc converter were derived. A power management strategy was developed and first simulated in RTDS. A Power Hardware-In-the-Loop (PHIL) simulation using RTDS is then presented. The main challenge of this PHIL is the requirement for a highly dynamic bidirectional Simulation-Stimulation (Sim-Stim) interface. This paper describes three different interface algorithms. The closed-loop stability of the resulting PHIL system is analyzed in terms of time delay and sampling rate. A prototype bidirectional Sim-Stim interface is designed to implement the PHIL simulation.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1874-1879
• /
• 2004

This paper validates new type electric power steering (EPS) system which is driven by a uni-direction rotational motor and two electromagnetic clutches. The assist motor of the new type EPS produces a torque for assisting the steering in only one direction and two electromagnetic clutches transmit the assist torque to the pinion gear in either left or right direction with respect to the steering rotation. In order to evaluate the static and dynamic characteristics of the new type EPS, the EPS has been modeled by using the well known customized software such as MSC.ADAMS and MSC.CarSim. The ADAMS software has been used to investigate the static characteristics of the proposed system. ADAMS, however, can not describe dynamics of a vehicle and perform the simulation under the various road conditions. Thus the dynamic characteristics of the vehicle including the EPS are analyzed very well by using the CarSim software. A sinusoidal steering input command is applied to the propose EPS system in order to evaluate the static characteristics, while the double lane changes are applied to the vehicle with the EPS in order to evaluate the dynamic performance. Through a series of simulations, we can conclude that the propose EPS shows the stable dynamic characteristics when the rotational direction is changed.

• Journal of the Korean Solar Energy Society
• /
• v.29 no.1
• /
• pp.64-69
• /
• 2009

This paper aims at enhancing the electric production efficiency of photovoltaic(PV) system. The electrical power of PV system is proportional to light intensity on a PV module surface. In this paper, we apply two types of systems to enhance power generation efficiency. First, of all, concentring sunlight using specular surface and one-axis tracking system which traces the sun with vertical direction are applied in this project. From this, we analyze the fixed type method and power generation efficiency.

• Proceedings of the KIEE Conference
• /
• 2000.11c
• /
• pp.491-493
• /
• 2000

The performance of insulate materials gets worse with stress time in power system and because this causes lowering of function and accidents in equipment, development and performance improvement of excellent insulate materials are needed to make stable system. In this paper, to study the influence of degradation in XLPE, inner semiconducting layer and outer semiconducting layer, we studied dielectric characteristics at temperature $25{\sim}100[^{\circ}C]$ and frequency $20{\sim}1[MHz]$ and volume resistivity at temperature $25{\sim}100^{\circ}C$, voltage.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.1040-1042
• /
• 2002

In general, satellite electrical power system plays an important role in its mission performance. To perform the mission successfully, the satellite should be provided with the sufficient power until end of life. In this paper shows that electrical boxes' design characteristic, energy balance analysis and power performance in satellite real operation.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.1
• /
• pp.89-94
• /
• 2018

The electric power system design of the electric vehicle are required to improve the performance. The electric power system on the electric vehicle are consist of a battery, a pedal sensor, an electric motor and a controller. In this paper, Automotive manufacture's various electric vehicle models are investigated and analyzed. The mathematical models for the electric power system are studied, and then important variables are considered. Simulation and experimental test results show the model of the electric power system on the electric vehicle and design parameter decision are effective to the electric vehicle design.