• 대한전기학회논문지:전력기술부문A
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• 제48권9호
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• pp.1096-1102
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• 1999

This paper discusses the evaluation of interconnection capacity of small cogeneration(SCOGN) systems to the power distribution systems from the viewpoint of voltage regulation. Power utilities are required to keep the customers' voltage profile over a feeder close to the rated value under all load conditions. However, it is expected that the interconnection of SCOGNs to the power distribution systems impacts on the existing voltage regulation method and customers' voltage variations. Therefore, SCOGNs should be integrated to the automated power distribution systems to prevent interconnection problems and supply high quality electricity to the customers. For these reasons, we should proceed with the evaluation of interconnection capacity of SCOGNs to the power distribution systems. However, it is generally impossible to perform actual testing on the power distribution systems, and standardized methodologies and guidelines are not developed to evaluate it. The criterion indexes for voltage regulation and variations are presented in order to evaluate the interconnection capacity of SCOGNs to the power distribution systems. In addition, the evaluation methodology of interconnection capacity of SCOGNs for power distribution systems is presented. It is expected that the resulted of this paper are useful for power system planners to determine the interconnection capacity of SCOGNs and dispersed storage and generation (DSG) systems to the power distribution systems.

• 대한전기학회논문지:전력기술부문A
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• 제50권10호
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• pp.447-453
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• 2001

This paper presents the unified reliability evaluation technique of distribution system. To calculate accurate reliabi1ity and reliability indices which can consider line limitation and voltage drop of distribution system, we employed the deterministic evaluation technique with PLOC technique. And to evaluate the distribution system, we presented the evaluating method which is based on Analytic network process. As a result, we can evaluate the distribution system and build the expansion planning of the system considering system load and reliability indices.

• 대한전기학회논문지:전력기술부문A
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• 제49권4호
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• pp.152-160
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• 2000

This paper presents an efficient evaluation method on the role of new energy storage systems, especially the secondary Battery Energy Storage (BES) systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a synthetical and quantitative manner, because they are very costly in the early stage of their development and commercialization. In this paper, the multiple functions of BES systems, which are operated at distribution systems, such as load levelling, effective utilization of power distribution systems and uninterruptible power supply at the emergency conditions are classified and analyzed. And then the quantitative evaluation methods of the multiple functions for BES systems are proposed using the mathematical modelling.

• 대한전기학회논문지:전력기술부문A
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• 제52권12호
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• pp.705-712
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• 2003

In this paper, we propose new unified methodologies of reliability and its cost evaluation in power distribution systems. The unified method means that the proposed reliability approaches consider both conventional evaluation factor, i.e. sustained interruptions and additional ones, i.e. momentary interruptions and voltage sags. Because the three voltage quality phenomena generally originate from the outages on distribution systems, the basic and additional reliability indices are summarized considering the fault clearing mechanism. The proposed unified method is divided into the reliability evaluation for calculating the reliability indices and reliability cost evaluation for assessing the damage of customer. The analytic and probabilistic methodologies are presented for each unified reliability and its cost evaluation. The time sequential Monte Carlo technique is used for the probabilistic method. The proposed DVL(Demand Varying Load) model is added to the reliability cost evaluation substituting the average load model. The proposed methods are tested using the modified RBTS(Roy Billinton Test System) form and historical reliability data of KEPCO(Korea Electric Power Corporation) system. The daily load profile of the each customer type in domestic are gathered for the DVL model. Through the case studies, it is verified that the proposed methods can be effectively applied to the distribution systems for more detail reliability assessment than conventional approaches.

• 대한전기학회논문지:전력기술부문A
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• 제51권5호
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• pp.232-237
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• 2002

It is increased for methodology to evaluate distribution power system interruption cost in power supply zones under competitive electricity market. This paper presents algorithms to evaluate system interruption cost in distribution power supply zones taking into consideration failure rate of distribution facilities and composite customer interruption cost. In this paper, it is introduced for weighting factor for each customer failure duration and failure rate of distribution facilities to evaluate reasonable system interruption cost in distribution power supply area. Also, this Paper estimates evaluation results of system interruption cost using a sample model system. Finally, evaluation results of system interruption cost based on failure rate of distribution facilities and composite customer interruption cost are shown in detail.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.213-217
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• 1998

This study overviews existing evaluation methods of classification accuracy using confusion matrix proposed by Cohen in 1960's, and proposes ISDd(Index of Spatial Distribution by distance) and ISDs(Index of Spatial Distribution by scatteredness) for the evaluation of spatial distribution of satellite image classification errors, which has not been tried yet. Index of spatial distribution offers the basis of decision on adoption/rejection of classification results at sub-image level by evaluation of distribution, such as status of local aggregation of misclassified pixels. So, users can understand the spatial distribution of misclassified pixels and, can have the basis of judgement of suitability and reliability of classification results.

• 전기학회논문지
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• 제59권12호
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• pp.2119-2124
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• 2010

Reliability evaluation of power distribution system is the evaluation for all customers supplied from one power source as main transformer located in substation. However, power sources include not only the main transformer but distributed generations. Typical reliability evaluation has focused on configuration of power system with one source including failure rates of equipment. In this paper, we focus on not only configuration but power sources as distributed generations. New reliability evaluation method using power supplied probability (PSP) is proposed. The proposed evaluation method are proved through case studies.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.9-16
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• 2003

In this paper, we propose a reliability evaluation method considering the momentary interruptions of power distribution systems. The results of research are concentrated on two parts. One is the analytic and probabilistic reliability evaluation of power distribution system considering the momentary interruptions and the other is the reliability cost evaluation that unifies the cost of sustained and momentary interruptions. This proposed reliability cost evaluation methodology is also divided into the analytic and probabilistic approach and the time sequential Monte Carlo method is used for the probabilistic method. The proposed methods are tested using the modified RBTS (Roy Billinton Test System) form and historical reliability data of KEPCO (Korea Electric Power Corporation) system. Through the case studies, it is verified that the proposed reliability evaluation and its cost/worth assessment methodologies can be applied to the actual reliability studies.

• 유통과학연구
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• 제20권10호
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• pp.19-29
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• 2022

Purpose: This study was conducted to gauge the economic evaluation and sample distribution of conserving the Belum Royal State Park (BRSP) in Perak, Malaysia and to identify factors influencing its use by the community. This study aims to examine community perception on the conservation of the Belum Royal State Park (BRSP) and maximum community's willingness to pay for park entry permits fees. Research design, data and methodology: A questionnaire survey was conducted involving a total of 280 respondents. The study adopted the Dichotomous Choice Contingent Valuation Approach (DC-CVM) and the Logistic Model, to estimate the maximum community's willingness to pay for park entry permits fees. Results: The results established that the factors of respondent's occupation, income, ecotourism influence on the BRSP and maximum entry price, significantly influenced visitors' decision on community's willingness to pay. The average community's willingness to pay was RM9.68 per person. Conclusions: In conclusion, surveillance and patrols in protected areas should be expanded. The extra expense for ensuring safety can be offset through income from ecotourism that should also benefit the local community on economic evaluation and equal distribution on the BRSP.

• 전기학회논문지
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• 제59권10호
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• pp.1741-1747
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• 2010

The development of overload management systems for distribution transformers offers new opportunities for improving the reliability of distribution systems. It allows network planners to optimize the system resource utilization and investment cost. Such an improvement in the flexibility of the distribution network is only possible if the operator has more accurate knowledge of the realtime conditions of distribution transformers. In this paper, we present an improved overload decision system for distribution transformers using realtime monitoring data. Our study can be categorized into two parts: (a) improvement in the criteria for judging the overload conditions of distribution transformers and (b) development of an overload evaluation system using realtime monitoring data. In order to determine the overload criteria, overload experiments are performed on sample transformers; the results of these experiments are used to define the relationship between the transformer overload and the increase in the top-oil temperature. To verify the accuracy of the experimental results, field tests are performed using specially manufactured transformers, the loads and top-oil temperatures of which can be measured. For arriving at online overload decisions, we propose methods whereby the measured load curve can be converted into an overload characteristic curve and the overload time can be calculated for any load condition. The developed system is able to evaluate the overload for individual distribution transformers and calculate the losses using realtime monitoring data.