• Journal of Power Electronics
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• 제15권1호
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• pp.235-245
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• 2015

This paper proposes a reactive current assignment and control strategy for a doubly-fed induction generator (DFIG) based wind-turbine generation system under generic grid voltage sag or swell conditions. The system's active and reactive power constrains during grid faults are investigated with both the grid- and rotor-side convertors (GSC and RSC) maximum ampere limits considered. To meet the latest grid codes, especially the low- and high-voltage ride-through (LVRT and HVRT) requirements, an adaptive reactive current control scheme is investigated. In addition, a torque-oscillation suppression technique is designed to reduce the mechanism stress on turbine systems caused by intensive voltage variations. Simulation and experiment studies demonstrate the feasibility and effectiveness of the proposed control scheme to enhance the fault ride-through (FRT) capability of DFIG-based wind turbines during violent changes in grid voltage.

• Transactions on Electrical and Electronic Materials
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• 제14권4호
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• pp.199-202
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• 2013

In order to study the effect of reactive diluents on the electrical insulation breakdown strength and mechanical properties of, a polyglycol and an aliphatic epoxy were individually introduced to an epoxy system. Reactive diluents were used in order to decrease the viscosity of the epoxy system; polyglycol acted as a flexibilizer and 1,4-butanediol diglycidyl ether (BDGE) acted as an aliphatic epoxy, which then acted as a chain extender after curing reaction. The ac electrical breakdown strength was estimated in sphere-to-sphere electrodes and the electrical breakdown strength was estimated by Weibull statistical analysis. The scale parameters of the electrical breakdown strengths for the epoxy resin, epoxy-polyglycol, and epoxy-BDGE were 45.0, 46.2, and 45.1 kV/mm, respectively. The flexural and tensile strengths for epoxy-BDGE were lower than those of the epoxy resin and those for epoxy-polyglycol were lower than those of the epoxy resin.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.237_238
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• 2009

This paper proposes coordinative control method between STATCOM installed within substation and other reactive power resources including Shunt Reactors and Shunt Capacitors and OLTC. Voltage/Reactive power control has various difficult aspects to control because of analysis and system dynamics error. This coordinative control method suggests practical algorithm regarding system voltage and reactive power status which is easy to implement in substation basis. In normal status, STATCOM-Shunts-OLTC are in operation. The proposed algorithm is tested and verified in EMTP/RV. And this is expected to be applied to control multiple reactive power devices combined with SCADA/EMS system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.813-816
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• 2005

This paper presents a method for harmonic elimination and reactive power compensation using an intervening firing method and passive power filter with is suitable to compensate rapidly changing loads and reactive power. The proliferation of three-phase thyristor phase-controlled converter of DC motor drives into a power system has the potential to increase the harmonic levels in the power system. The design procedure of an intervening firing method and passive power filter capable of reducing the voltage and current harmonics produced by converter supplied from a source having internal large inductive impedance is offered. The analysis uses the or CAD PSpice to model three-phase thyristor phase-controlled converter of DC motor drives as well as the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1189-1191
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• 1999

This paper deals with the real and reactive power control of BESS(Battery Energy H Storage System) interconnected to power system. The real and reactive power control of proposed customer side BESS are performed by controlling the amplitude and the phase of inverter output voltage via power flow equation. Also in order to control the amplitude and phase of output voltage of proposed BESS, single-pulse width control method is used. The BESS and controller is implemented and the active and reactive power control is simulated by using the PSCAD/EMTDC simulation program.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1027-1029
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• 2003

STATCOM which is connected the load parrallel with capacitor. is the reactive power compensation device. In this paper. appling the PSIM(POWERSIM) software to STATCOM system. it is simulated the reactive power compensation of balancing load. And, setting a thoroughly going over it's results. we confirmed the function propriety of developed STATCOM system. So, it will be applied the reactive power compensation experimentation of the developing 30kVA STATCOM at our laboratory.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.111-114
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• 2000

Harmonics and fundamental reactive power of nonlinear loads in serious unbalanced power condition are compensated by current synchronous detection(CSD) theory which is also acceptable for single phase power system, but the CSD theory is not suitable any more in case of controlled independently harmonics and reactive component. Therefore a new algorithm the extended current synchronous detection (ECSD)theory for a three phase active power filter based on decomposition of fundamental reactive distorted components is proposed in this paper. The proposed ECSD theory is simulated and tested comparison with a few power theories under asymmtrical condition in power system.

• 대한전자공학회논문지
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• 제26권11호
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• pp.1658-1665
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• 1989

Reactor design considerations over several critical parameters for a planar type reactive ion etcher are given. The etch uniformity is taken as a principal design constraint. The characteristics of economicaly available vacuum pumping system are taken as practical design constraints. A set of theoretical conditions on the chamber geometry and on the gas delivery and vacuum system, that satisfy the design constraints, are derived from basic properties of RF glow discharge and gas dynamics. The theoretical results are applied to decide design parameters of a practical single-wafer-per-chamber planar type reactive ion etching machine.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1996년도 춘계학술발표회 초록집
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• pp.111-114
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• 1996

Hydrogen generation by dissociation of water is described. The major force for the dissociation comes from the oxidation potential of the reactive metal reacting with water whereas the minor role is played by electrical discharge which helps sustain the reaction. A premixed reactive metal/water system undergoes a fast hydrogen generation upon the ignition by an electrical pulse. In another method the reactive metal can be fed into the discharge. Some characteristics of the methods are discussed.

• Transactions on Electrical and Electronic Materials
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• 제15권2호
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• pp.77-80
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• 2014

The effect of reactive diluents on the ac electrical treeing in epoxy/nanosilicate systems was studied, in a needle-plate electrode geometry. Diglycidyl ether of bisphenol A (DGEBA) type epoxy was used as a base resin, and layered silicate was used as a nano-sized filler. Polyglycol (PG) or 1,4-butanediol diglycidyl ether (BDGE) was introduced as a reactive diluent to the DGEBA/nanosilicate system, in order to decrease the viscosity of the nanocomposite system. PG acted as a flexibilizer, and BDGE acted as a chain extender, after the curing reaction. To measure the treeing propagation rate, a constant alternating current (ac) of 10 kV/4.2 mm (60 Hz) was applied to the specimen, in a needle-plate electrode arrangement, at $30^{\circ}C$ of insulating oil bath. When 10 kV/4.2 mm (60 Hz) was applied, the treeing propagate rate in the DGEBA system was $1.10{\times}10^{-3}$ mm/min, and that in the DGEBA/PG system was $1.05{\times}10^{-3}$ mm/min. As 1.5 wt% of nanosilicate was added to the DGEGA/PG system, the propagation rate was $0.33{\times}10^{-3}$ mm/min. This meant that the nano-sized layered silicates would act as good barriers to treeing propagation. The effect of chlorine content was also studied, and it was found that chlorine had a bad effect on the electrical insulation property of the epoxy system.