• Proceedings of the KIEE Conference
• /
• 2002.11b
• /
• pp.280-282
• /
• 2002

As EG(Embedded Generation : photo-voltaic, wind, combined heat and power, fuel cell, small hydro etc.) grows fast in adopting to peak load reducing at the middle or the end of distribution system, there much has been interested in interconnection of EG. This paper discusses the various issue of a embedded generator to power system and shows the simulation of its various situation that could happen (focusing on load-flow by EG) by using a commercial software CYME(PSAF) for load-flow. With a result of above simulation, this paper shows a way of possible solution briefly.

• The KSFM Journal of Fluid Machinery
• /
• v.14 no.6
• /
• pp.68-75
• /
• 2011

This study simulated the effect of steam injection on the performance and operation of a gas turbine combined heat and power (CHP) system. A commercial simple cycle gas turbine was analyzed. A full off-design analysis was carried out to investigate the variations in not only engine performance but also the operating characteristics of the compressor caused by steam injection. Variation in engine performance and operation characteristics according to various operation modes were examined. First, the impact of full steam injection was investigated. Then, operations aiming to guarantee a minimum compressor surge margin, such as under-firing and partial steam injection, were investigated. The former and latter were turned out to be relatively superior to each other in terms of power and efficiency, respectively.

• New & Renewable Energy
• /
• v.10 no.1
• /
• pp.41-49
• /
• 2014

For a proper valuation of wind power project, it is necessary to consider volatilities of key parameters such as annual energy production, electricity sales price, and long term interest rate. Real option methodology allows to calculate option values of these parameters. Volatilities to be considered in wind project valuation are 1) annual energy production (AEP) estimation due to meteorological variation and estimation errors in wind speed distribution, 2) changes in system marginal price (SMP), and 3) interest rate fluctuation of project financing which provides refinancing option to be exercised during a loan tenor for commercial scale projects. Real option valuation turns out to be more than half of the sales value based on a case study for a FIT scheme wind project that was sold to a financial investor.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.55 no.12
• /
• pp.549-554
• /
• 2006

Available transfer capability(ATC) is an important indicator of the usable amount of transmission capacity accessible by several parties for commercial trading in power transaction activities. This paper deals with an application of optimization technique for available transfer capability(ATC) calculation and analyzes the results of ATC by considering several constraints. Especially several optimization techniques are used to solve the ATC problem with state-steady security constraints. The results are compared with that of repeat power flow(RPF), sequential quadratic programming(SQP) and linear programming(LP). The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.524-526
• /
• 2001

The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers, with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper calculate the elasticity of each loads and analysis the effects of electric power demands and spot pricing as a function of elasticity in competitive electricity market.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2027-2029
• /
• 1998

We have developed a compact high frequency switch mode converter (HFSMC) power supply with DC 50 kV output voltage and 10 kW output power. Since the inverter circuit uses 25 kHz rescharging scheme, the current is flowing with t kHz. For the efficient output voltage transform performed a simple design process using the transformer principle and the commercial specification. For the DC 50 kV output, we employed 7 pa windings of secondary coils for the series stac connection of the output with full-bridge rectifi In this paper the design detail and the test re the high frequency transformer together with HFSMC power supply are presented.

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.2
• /
• pp.269-272
• /
• 2016

Distribution management system or microgrid energy management system plays an important role in monitoring, operation and control of electrical distribution systems by utilizing IT infrastructure. Nowadays, the rapid increase of the distributed resources makes the conventional management system have some additional functionality for the reliable operation due to intermittent renewables and the efficient operation on the economical purpose. In this paper, the brief standard software functional requirements of microgrid energy management system are provided through survey of the recent commercial products of the major vendors, and furthermore the architectures of microgrid energy management system are provided in comparison with major suppliers' microgrid energy management system. The summary of investigation will be able to make the developers and researchers focus on the specific functionality in the real world.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.5 no.4
• /
• pp.10-16
• /
• 2008

In this paper, the authors benchmark a servo valve model for the fuel supply system of Auxiliary Power Unit (APU) in the KHP helicopter. This valve is directly driven with a torque motor, and the size of small gap controlled by a flapper can make change of flow rate under given pressure drop between inlet and outlet. CFD analyses using a commercial code, ANSYS-CFX 10 are performed for the series of three-dimensional models at various openness conditions. The computational results on simplified models show that CFD can play a fine roll in the design of flow path as well as in the estimation of flow force due to its precision and good repeatability. Consequently, the CFD analysis helps valve designers to understand its flow characteristics from the basis of physical fundamentals.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.287-294
• /
• 2002

CAES which is called as a compressed air energy storage was firstly developed at Huntorf, German in 1978. The capacity of that system was 290MW, and it can be treated as a first commercial power plant. CAES has a lot of merits, such as saving the unit price of power generation, averaging the peak demand, improvement of maintenance, enlarging the benefit of dynamic use. According to the literature survey, the unlined rock cavern should be proposed to be a reasonable storing style as a method of compressed air storage in Korea. We decided the hill of the Korea Institute of Geoscience and Mineral Resources as CAES site. If we construct the underground spaces in this site, the demand for electricity nearby Taejon should be considered. So we could determine the capacity of the power plant as a 350MW, This capacity needs a underground space of 200,000㎥, and we can conclude 4 parallel tunnels 550m deep from the surface through the numerical studies, Design parameters were achieved from 300m depth boring job and image processing job.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.6
• /
• pp.28-34
• /
• 2011

This paper describes the development of the transient analysis model of 345[kV] 100[MVA] STATCOM and the result of the performance analysis. The Korea power utility company, KEPCO began a commercial operation of a 100[MVA] STATCOM(Static synchronous COMpensator) at 345[kV] Migeum substation in Seoul. In order to operate a new control device like STATCOM to the power system, suitable transient model is needed. Therfore, Korea Electric Power Coporation(KEPCO) developed a transient analysis models using EMTDC/PSCAD. The development of this transient analysis model is based on the actual STATCOM S/W algorithm and H/W specification that was provided by its manufacture. Through this model, the transient/dynamic performance of STATCOM at Migeum substation can be analyzed.