• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.1
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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.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.12
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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.

• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.633-646
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• 2014

Purpose: The conventional predicted MFTBF by military standard has a wide discrepancy to that of real-world operation, which leads to overstock and increase operation cost. This paper introduces a analyzing frame using operational reliability and cost data to overcome the discrepancy, and provides reliability improvement process employing the analyzing frame. Methods: This paper suggests Reliability-Cost Matrix (R-C Matrix) and Operational Reliability & Cost Index (ORCI) as a tool for reliability evaluation. Results: KOREIP(KAI's Operational Reliability Evaluation and Improvement Process) is developed employing Reliability-Cost Matrix and Operational Reliability & Cost Index. Conclusion: KOREIP provides a process and its activities based on Reliability-Cost Matrix frame. The process and activities leads reliability improvement of aerospace electronic equipments by means of categorizing and follow-up action based on the concept of frame.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.8
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• pp.457-462
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• 2003

This paper presents an optimal operating strategy of distributed generation (DG) with reliability worth evaluation of distribution systems. Using DG for peak-shaving unit could reduce the overall system operating cost, and using DG for standby power unit could reduce the customer interruption cost. If DG operating cost is less than utility power cost in peak time, DG should be running to reduce the overall system operating cost. When customer interruption cost enlarges, however, standby power strategy may be the better operating strategy than peak-shaving strategy. Selection of whether DG should be operated for peak-shaving or for standby power, needs the accurate reliability worth evaluation and the accurate power cost evaluation. Instead of using annual average reliability worth, the concept of hourly reliability worth is introduced in this paper to determine the optimal operating decision of DG. Applying suggested hourly reliability worth, the distribution companies that possess DG could set up the optimal operating strategy of DG.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.133-135
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• 2002

It is raised for methodology to evaluate power system reliability using interruption cost which is converted customer loss due to interruption into cost according to power industry is rushed into competition appearance. This paper presents algorithms to evaluate reliability of distribution power system taking into consideration customer interruption cost. Customer interruption cost is considered as one of the valuable index to estimate reliability of the distribution power system from customer situation. Also. this paper estimate evaluation results regarding the reliability of distribution power system using a sample model system. Finally, evaluation results of unserved energy and system interruption cost based on customer interruption cost are shown in detail.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.267-269
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• 2001

This paper presents algorithms to evaluate reliability of distribution power system taking into consideration customer interruption cost. Customer interruption cost is considered as one of the valuable index to estimate reliability of the distribution power system from customer situation. Also, this paper estimate evaluation results regarding the reliability of distribution power system using a sample model system. Finally, evaluation results of unserved energy and system interruption cost based on customer interruption cost are shown in detail.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1033-1035
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• 1998

This paper presents a new analytical method for assessing outage cost of composite power system with considering transmission system uncertainty. Composite power system ELDC(CMELDC) was developed and proposed from reliability evaluation of composite power system in order to analysis the outage cost on HLII. In this study, considering the characteristic of each load point, the CMELDC was used for outage cost assessment and reliability evaluation at each load point. The characteristics and effectiveness of this methodology are illustrated by the case study (IEEE-RTS 24Buses).

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.286-292
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• 2005

As the power industry moves towards open competition, there has been a call for methodology to evaluate power system reliability by using composite interruption cost. This paper presents algorithms to evaluate the interruption cost of distribution power systems by taking into consideration the failure source and the composite customer interruption cost. From the consumer's standpoint, the composite customer interruption cost is considered as the most valuable index to estimate the reliability of a power distribution system. This paper presents new algorithms that consider the load by customer type and failure probability by distribution facilities while calculating the amount of unserved energy by customer type. Finally, evaluation results of unserved energy and system interruption cost based on composite customer interruption cost are shown in detail.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.143-146
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• 2004

This paper presents a method to improve reliability by dispersed generation (DG) installation considering load types and interruption cost. The objective functions such as power losses cost, operation cost of DGS, power buy cost and interruption cost are minimized for reliability improvement and efficient operation. The several indices for reliability evaluation are improved by dispersed generation system installation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.175-180
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• 2006

Total conceptual cost estimates and the assessment of the reliability of these estimates are critical in the early stages of a building construction project. The purpose of this study is to propose the method to clients or estimators for improving the reliability of conceptual cost estimates by evaluating the reliability of conceptual cost estimates. The data from 83 building construction projects were collected for this study. The results showed that the proposed method can propose alternatives to clients or estimators for improving the reliability of conceptual cost estimates with the process of evaluation, review and feedback. This process can assist clients in their evaluation of the reliability of the estimated cost and the probability of exceeding the target cost, and in their re-estimation after dealing with the elements that influence the conceptual cost estimate badly.