ارزيابي قابليت اطمينان نواحي مختلف سيستم توزيع با در نظر گرفتن تغييرات بارو ظرفيت تغذيه ي جايگزين

چكيده انگليسي :

Reliability Assessment for Different Zones of Distribution System Considering Load Variations and Alternative Supply Capacity Mehdi Karimzadeh m karimzadeh@ec iut ac ir nima665@yahoo com Date of Submission May 9 2010 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Akbar Ebrahimi ebrahimi@cc iut ac ir Abstract Power systems reliability has been one of the judgment criteria for the quality of these systems for many years With regard to technology growth in the recent decades and increase in sensitivity of the customers to unavailability of the electric energy reliability issue has achieved more importance and plays an outstanding role in power systems design operation management and planning According to statistical studies done by the relevant utilities about 80 percent of the customer interruptions are caused by failures occurrence in distribution systems and the remaining 20 percent are due to the generation and transmission parts of a power system Investment costs in power plants and transmission system with the aim of achieving a certain level of power system reliability are typically much greater than the costs needed for the distribution system to achieve the same reliability level Hence distribution system reliability analysis is an efficient way to improve the power system reliability That s why a lot of power system reliability researches published in the recent years have focused on the reliability issue in distribution systems On the other hand market liberalization in electric power industry has raised the importance of cost and or reliability evaluation of distribution systems Variation of electric energy and interruption costs in different load conditions as a function of time can be useful in electric power pricing system operation and management that is based on system reliability requirements The methods for calculation of distribution reliability indices can be classified into analytical and Monte Carlo Simulation MCS methods Each of these approaches has some advantages and disadvantages In the thesis ahead the analytical method is considered By this approach considering the location of protection and isolation devices the distribution system of interest is partitioned into its reliability zones Then reliability indices are computed in each reliability zone each feeder and whole of the system In this research as a case study the reliability zones indices of the distribution system connected to bus 2 of the RBTS Roy Billinton Test System has been calculated where hourly load curve is considered for each class of customers in the system By the cited method and considering hourly load curves the reliability assessment of the system is performed for each reliability zone and in the different load conditions The main benefit of this evaluation technique is that greater amount of information is obtainable for various load points in desired time intervals Results of the calculated indices show that the interruption frequency oriented indices are constant at the different load conditions while the interruption duration indices can be varied by the variation of load conditions A sensitivity analysis has performed by increasing the alternative supply capacity and its impact on the interruption duration of the feeders and whole of the system are considered A reliability saturation concept has also been introduced to determine the capacities corresponding to the upper limits of the feeders and system reliability Having calculated various indices of the reliability zones they are ranked with a criterion of their expected interruption duration at each hour and whole of a typical day This ranking can be used in distribution system optimal operation and management Keywords 1 Distribution System 2 Reliability Zone 3 Time Varying Load 4 Alternative Supply

كريم زاده، مهدي

ارزيابي قابليت اطمينان نواحي مختلف سيستم توزيع با در نظر گرفتن تغييرات بارو ظرفيت تغذيه ي جايگزين

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