• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.3
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• pp.232-239
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• 1990

A new algorithm is suggested to solve the optimal reactive power and voltage control (optimal VAR control) problem. The model minimizes the real power losses in the system. The constraints include the reactive power limits of the generators, limits on the bus voltages and the operating limits of control variables-the transformer tap positions generator terminal voltages and switchable reactive power sources. The method presented herein, using a newly developed Jacobian decomposition method, employs linearized sensitivity relationships of power systems to establish both the objective function for minimizing the system losses and the system performance sensitivities relating dependent and control variables. The algorithm consists of two modules, i.e. the Q-V module for reactive power-voltage control, and load flow module for computational error adjustments. In particular the acceleration factor technique is introduced to enhance the convergence property in Q-V module. The combined use of the afore-mentioned two modules ensures more effective and efficient solutions for optimal reactive power dispatch problems. Results of the application of the method to a sample system and other worst-case systems demonstrated that the algorithm suggested herein is compared favourably with conventional ones in terms of computation accuracy and convergence characteristics.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.348-351
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• 2006

This paper presents preliminary laboratory investigations on the electrokinetic (EK) remediation coupled with permeable reactive barrier (PRB) system. Atomizing slag was adopted as a PRB reactive material for remediation of groundwater contaminated with inorganic and/or organic substances. A series of laboratory experiments were performed with variable conditions such as (i) type of contaminant, (ii) applied electric field strength, (iii) processing time, and (iv) the application of PRB system. From the preliminary investigations, the coupled technology of EK with PRB system would be effective to remediate contaminated grounds without the extraction of pollutants from subsurface due to the reactions between the reactive materials and contaminants.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.45-47
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• 1994

The simulation of reactive power compensation in 5-bus and 25-bus system was conducted using transmission-line loss system identification method. Sensitivities of maximum load-power with respect to reactive power compensation was identified by the simulation. With sufficient reactive power compensation at the first voltage-collapsing load-bus, the first voltage collapse could be prevented until the next voltage-collapsing load-bus lost its voltage stability. And the total compensated reactive power at the first voltage-collapsing bus means reactive power margin of voltage collapse or distance to voltage collapse. This quantity can be useful for determining the size of compensating devices or the site to compensate.

• Textile Coloration and Finishing
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• v.32 no.1
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• pp.27-37
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• 2020

Low temperature dyeing properties of wool with reactive dyes and acid dyes were investigated for the feasibility study of their application to hair dyeing. The low temperature(30℃, 40℃) dyeing achieved light depth of shade in wool dyeing and reactive dyeing exhibited relatively higher color strength and chroma values than acid dyeing. Leveling agent slightly improved the levelness of the wool dyeing and the leveling properties of dyed wool at low temperature were good to excellent, irrespective of the dyes applied. Color loss during the repeated shampooing was in the range of 9.6~22.2% for reactive dyes and -7.4~31.5% for acid dyes and in some cases, the color fastness to shampooing was reasonable level. The overall experimental results showed that the application of low temperature wool reactive dyeing to hair dyeing is sufficiently feasible in terms of dyeability and color fastness to shampooing.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.398-403
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• 1998

This paper describes a controller design for the stator reactive power generator in the transmission system. The controller of static reactive power generator was designed using a mathematical model and non-linear state feedback. The performance of controller was verified using computer simulation with EMTP code and experimental work with scaled-model. The dynamic interaction with a simple power system was also analyzed using both the simulation model and hardware scaled-model. Both simulation and experimental results prove that the controller using PI block and non-linear state feedback offers better performance than the controller using PI block only.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.87-88
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• 2006

Generator has responded quickly with variation of power system voltage and is controlled at real time. As a reactive power source, generator is revalued better than power condenser and as a reactive power sink, is revalued. But Domestic generators scarcely have been tested and operated to reactive power capability. In case of power system fault, operators wouldn't quickly take a follow-up measures about reactive power disturbance. Therefore generator reactive power capability verification strategy must be developed, several generators is tested as a exhibition since 2004. This paper is extract from the test contents.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.678-682
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• 1999

In this paper, we propose the algorithm which can control active power and reactive power independently in Battery Energy Storage System. The proposed algorithm is based on the instantaneous power theory that the inner product of the voltage vector and current vector represents the active power and the cross product of those represents the reactive power, and it can control active power and reactive power independently. To verify the validity of the proposed algorithm, we make model of the real power system in th KERI and simulate this algorithm. As a result of this simulation, we verified that the proposed algorithm can control active power and reactive power independently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.398-403
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• 2003

The purpose of this paper is to investigate purification characteristic of soil-bentonite landfill liner and to develop a desirable liner system. In order to clarify the purification characteristics, high pressure column tests using soil-bentonite, reactive soil-bentonite and reactive bentomat were carried out in the presence of water and leachate. The test results indicated that the significant amount of NH$_3$-N, Pb and Cu was removed through the reactive soil-bentonite liner system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.457-458
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• 2007

The reactive reserves of generators is close to voltage stability. This characteristic has led to the development of a few year monitoring the reactive reserves. In this paper, the reactive reserves have been calculated considering the generator capability curve. In addition, through dividing the systems using electric distance, the reactive reserves of each area has been calculated. Then, using the correlative relationship between reactive reserves and PV margins, the method for monitoring the voltage stability is proposed. The proposed method is tested on PSS/E test system and KEPCO system.

• Textile Coloration and Finishing
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• v.19 no.5
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• pp.17-23
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• 2007

As polyvinyl alcohol(PVA) filament yarn is commercially used in many fields due to its high strength and modulus properties. This research was carried out to study the dyeing behavior of PVA and to find out appropriate dye for better dyeing. As the dyeing behavior of PVA fiber is similar to cellulose due to the same functional group, reactive and vat dyes were selected for the dyeing. Color strength of PVA fibers treated with vat dyes was found to be better than those with reactive dyes, because of the low fixation of reactive dye on fibers. Most of the reactive dye may became hydrolyzed, and flushed away with water in washing. Colorfastness to laundering was shown to be very high for both of the reactive-dyed and vat-dyed PVA fibers.