• 전기학회논문지
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• 제57권9호
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• pp.1531-1535
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• 2008

In the past vertically integrated power system, the power utility forecasted power demand and invested new power plants to keep a system adequacy. However, in the competitive electricity markets, a principle part of the capacity investment is market participants who decided the investment to maximize their profit. Especially, one of the main factors in their long-term decision making is the retrieval of fixed costs (construction costs). This paper presents the capacity payment in electricity power markets. The capacity payment (CP) in Cost Based Pool (CBP) is needed to recover fixed costs. However, CP in CBP was applied not only recovering fixed costs but also ensuring supply reliability. In order to operate harmonious power markets, pool needs reasonable CP mechanism. This paper analysis CP using capacity proportion and Reliability Pricing Model (RPM).

• 대한전기학회논문지:전력기술부문A
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• 제48권2호
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• pp.113-118
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• 1999

In this, sensitivity based approach to estimate BITC(bilateral interchange transfer capacity) considering the real power flow control function of FACTS devices is presented. The real power flow setting of the FACTS devices is adjusted so that it transfers the power flow from the first violation point of transmission capacity to other transmission lines in the power system, thus allowing more power to be transferred from the specified generator bus to the specified load bus. The transfer between the two bus locations is increased from this new operating condition until a violation of transmission capacity limits occurs or until the setting of the FACTS devices can no longer be adjusted. The proposed algorithm is illustrated using examples of small and real life power system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.802-807
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• 1998

The main drawback of parallel type active power filters (APF) is the large capacity required for harmonic compensation. This paper evaluates the APF capacity requirement of harmonic/reactive power compensation for thyristor converter load. Theoretically achievable maximum power factor under partial load is evaluated. And it is shown that the APF capacity can be considerably reduced while slightly sacrificing the filtering performance by deliberately limiting the peak current of the APF.

• Journal of Power Electronics
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• 제19권5호
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• pp.1315-1325
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• 2019

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance ${\varepsilon}_U$ and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

• 한국통신학회논문지
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• 제28권10A호
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• pp.788-795
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• 2003

We analyze the performance of a truncated power controlled CDMA(code division multiple access) cellular systems with base station antenna arrays. Erlang capacity and the channel capacity which is a maximum date rate to maintain almost error free communication are analytically derived. The numerical results show there can be a substantial increase in Erlang capacity and in channel capacity by antenna arrays incorporating with the truncated power control scheme.

• Journal of electromagnetic engineering and science
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• 제1권2호
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• pp.120-125
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• 2001

The capacity improvement in the DS-CDMA system can be obtained by allowing spectrum-overlap between adjacent channels. In this paper, an analysis for capacity improvement is newly considered according to the various chip waveforms in the partial spectrum-overlapped DS-CDMA system. Optimum-overlapping ratio is numerically found to obtain maximum capacity improvement for each chip waveform. Assuming the bandwidth containing 95% of the total power, i.e., 95% power bandwidth, rectangular chip waveform has the largest capacity improvement in the considered chip waveforms and then the amount of improvement is 136.5% at overlapping ratio 1.5 for BER = $10^{-3}$TEX> . Furthermore, as the required BER becomes lower, the capacity improvement gets smaller for a1l of chip waveforms. For the unequal power channels, it is shown that the larger capacity improvement is achieved as the power of desired channel becomes larger than that of adjacent channels. And the capacity improvement can be obtained even though the desired channel power is lower than the adjacent channel power.

• 한국태양에너지학회 논문집
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• 제32권1호
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• pp.25-31
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• 2012

This paper presents the characteristics of power generation output at Haeng-won wind farm and how to determine the optimized ESS capacity for power stabilizing. Depend on the fluctuation rate of wind power output variation, wind farm capacity and site, power stabilization will be impacted. Therefore, we need to determine proper ESS capacity. Using the actual data of Haeng-won wind farm from 2009. 3 to 2010.2., capacity of ESS was determined by moving average value. To verify the proposed algorithm, simulations are carried out with PSCAD/EMTDC program. As a result, optimal ESS capacity of Haeng-won wind farm in Jeju is estimated about 1.63 MWh.

• 수산해양기술연구
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• 제48권1호
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• pp.29-39
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• 2012

Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen's logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.

• Journal of Power Electronics
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• 제13권3호
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• pp.497-506
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• 2013

This paper proposes a new method to improve the available battery capacity in electric vehicles by connecting lead-acid batteries with lithium-ion battery in parallel to supply power. In addition, this method combines the discharge characteristics of batteries to improve their efficiency and lower their cost for electric vehicles. A lithium-ion battery set is used to connect with N sets of lead-acid batteries in parallel. The lead-acid battery supplies the initial power. When the lead-acid battery is discharged by the load current until its output voltage drops to the cut-off voltage, the power management unit controls the lead-acid battery and changes it to discharge continuously with a small current. This discharge can be achieved by connecting the lead-acid battery to a lithium-ion battery in parallel to supply the load power or to discharge its current to another lead-acid or lithium-ion battery. Experimental results demonstrates that the available capacity can be improved by up to 30% of the rated capacity of the lead-acid batteries.

• Journal of Communications and Networks
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• 제14권3호
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• pp.257-266
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• 2012

A decode-and-forward two-way relay system benefits from orthogonal frequency division multiplexing (OFDM) and relay transmission. In this paper, we consider a decode-and-forward two-way relay system over OFDMwith two strategies: A joint subcarrier matching algorithm and a power allocation algorithm operating with a total power constraint for all subcarriers. The two strategies are studied based on average capacity using numerical analysis by uniformly allocating power constraints for each subcarrier matching group. An optimal subcarrier matching algorithm is proposed to match subcarriers in order of channel power gain for both transmission sides. Power allocation is defined based on equally distributing the capacity of each hop in each matching group. Afterward, a modified water-filling algorithm is also considered to allocate the power among all matching groups in order to increase the overall capacity of the network. Finally, Monte Carlo simulations are completed to confirm the numerical results and show the advantages of the joint subcarrier matching, power allocation and water filling algorithms, respectively.