scholarly journals Critical System Cascading Collapse Assessment for Determining the Sensitive Transmission Lines and Severity of Total Loading Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nur Ashida Salim ◽  
Muhammad Murtadha Othman ◽  
Ismail Musirin ◽  
Mohd Salleh Serwan
Keyword(s):  
Transmission Lines ◽  
Loading Condition ◽  
Critical Power ◽  
Maximum Level ◽  
Accurate Calculation ◽  
Critical System ◽  
Hidden Failure ◽  
Average Probability ◽  
Accurate Probability

This paper presents a computationally accurate technique used to determine the estimated average probability of a system cascading collapse considering the effect of hidden failure on a protection system. This includes an accurate calculation of the probability of hidden failure as it will give significant effect on the results of the estimated average probability of system cascading collapse. The estimated average probability of a system cascading collapse is then used to determine the severe loading condition contributing to a higher risk of a system cascading collapse. This information is important because it will assist the utility to determine the maximum level of increase in the system loading condition before the occurrence of critical power system cascading collapse. Furthermore, the initial tripping of sensitive transmission line contributing to a critical system cascading collapse can also be determined by using the proposed method. Based on the results obtained from this study, it was found that selecting the accurate probability of hidden failure is very important as it will affect the estimated average probability of a system cascading collapse. Comparative study has been done with other techniques to verify the effectiveness of the proposed method used in the determination of sensitive transmission lines.

Comparison between the System Cascading Collapse Based Hidden Failure and Fault Chain Theory in the Determination of Sensitive Transmission Lines

2015 ◽  
Vol 785 ◽  
pp. 440-444
Author(s):  
Nur Ashida Salim ◽  
Muhammad Murtadha Othman ◽  
Ismail Musirin ◽  
Mohd Salleh Serwan
Keyword(s):  
Power System ◽  
Comparative Study ◽  
Transmission Lines ◽  
Critical Power ◽  
Considerable Effect ◽  
Accurate Calculation ◽  
Hidden Failure ◽  
Average Probability ◽  
Chain Theory

This paper presents a computationally accurate technique used to determine the estimated average probability of a system cascading collapse in association with the effect of hidden failure on a protection system. This includes an accurate calculation of the probability of hidden failure as it will provide considerable effect on the results of the estimated average probability of system cascading collapse. The estimated average probability of a system cascading collapse is then used to determine the sensitive transmission contributing to a higher risk of a system cascading collapse. This information is important because it will assist the utility to determine the critical transmission lines before the occurrence of critical power system cascading collapse. Comparative study has been done with other techniques to verify the effectiveness of the proposed method used in the determination of sensitive transmission lines.

Severe Total Loading Condition Attributed by a Significant Impact of Dynamic Power System Cascading Collapse

2015 ◽  
Vol 785 ◽  
pp. 445-449
Author(s):  
Nur Ashida Salim ◽  
Muhammad Murtadha Othman ◽  
Ismail Musirin ◽  
Mohd Salleh Serwan ◽  
Stendley Busan
Keyword(s):  
Power System ◽  
Dynamic System ◽  
Loading Condition ◽  
Critical Power ◽  
Protection System ◽  
Dynamic Power ◽  
Dependent Component ◽  
Hidden Failure ◽  
Average Probability

Cascading outage is a sequence of multiple dependent component outages that gradually happened in a power system. One of the main reasons is due to the hidden failure in a protection system that may cause to a power system instability leading to a system cascading collapse. This paper presents a computationally realistic technique used to determine the estimated average probability of a dynamic system cascading collapse in conjunction with the effect of hidden failure on a protection system. This includes a realistic calculation of the probability of hidden failure as it will provide significant impact on the results of the estimated average probability of dynamic system cascading collapse. The estimated average probability of a system cascading collapse is then used to identify the severity of total loading condition leading to a higher risk of a dynamic system cascading collapse. This information is essential for the reason that it will assist the power system utility to determine the highest point of increased system loading condition before the occurrence of critical power system cascading collapse.

Accurate calculation of ion flow field under HVDC bipolar transmission lines

1988 ◽  
Vol 3 (1) ◽  
pp. 368-376 ◽  
Author(s):  
B.L. Qin ◽  
J.N. Sheng ◽  
Z. Yan ◽  
G. Gela
Keyword(s):  
Flow Field ◽  
Transmission Lines ◽  
Accurate Calculation ◽  
Ion Flow

scholarly journals A Methodology for Optimal Design of Transmission Lines to Protection against Lightning Surges in Presence of Arresters

2020 ◽  
Vol 9 (1) ◽  
pp. 105-110
Author(s):  
R. Shariatinasab ◽  
R. Azimi
Keyword(s):  
Transmission Lines ◽  
Geometric Model ◽  
Design Parameters ◽  
Target Number ◽  
Planning Stage ◽  
Shielding Failure ◽  
Surge Arresters ◽  
The Monte Carlo Method ◽  
Optimal Value

In this paper, a methodology for determination of the optimal value of protection design parameters, i.e. tower footing resistance, insulation strength, and surge arresters’ rating in the planning stage of transmission lines (TLs) is presented. This method calculates the shielding failure flashover rate (SFFOR) of TLs, based on Electro-geometric model (EGM) of TLs, and the back flashover rate (BFR) of TLs, based on the Monte Carlo method, in which the accuracy of the proposed methodology has been verified by comparing the resultant results with those obtained with the use of the IEEE FLASH program. The proposed method can be directly used to achieve the minimum lightning flashover rate (LFOR) of TLs by the minimum investment cost. Also, it can be used, indirectly, for determination of the appropriate value of the footing resistance, insulation strength and arresters’ rating to satisfy any target number of LFOR that might be specified by the utilities or standards.

scholarly journals Production of dry fermented fish sausages by using different fish species and determination of the microbiological qualities

2021 ◽  
Vol 38 (3) ◽  
pp. 329-336
Author(s):  
Berna Kılınç ◽  
Şükran Çaklı
Keyword(s):  
Staphylococcus Aureus ◽  
Dicentrarchus Labrax ◽  
Storage Period ◽  
Maximum Level ◽  
Refrigerated Storage ◽  
Fermented Fish ◽  
Alternative Product ◽  
Fermented Sausages ◽  
Dry Fermented Sausages

In this study frozen-thawed rainbow trout (Onchorhynchus mykiss) and seabass (Dicentrarchus labrax) fillets were used for preparing of dry fermented fish sausages. The total mesophilic aerob bacteria (TMAB), total psychrophilic aerob bacteria (TPAB), yeast–mould (YM), lactic acid bacteria (LB), Enterobactericeae (EB), Staphylococcus aureus (SA) changes of these dry fermented sausages were examined in the refrigerated storage at 6-8˚C. At the end of the storage period of 90 days, the results of the TMAB, TPAB, YM, LB, EB and SA counts of dry fermented seabass sausages were determined as 6.25, 7.01, 3.61, 5.31, <1.0 ve <1.0 log cfu/g, while, TMAB, TPAB, YM, LB, EB and SA counts of dry fermented trout sausages were found as 6.57, 7.20, 4.44, 5.14, <1.0 ve <1.0 log cfu/g, respectively. In this study both fermented fish sausages were determined as too much dried and exceeded the microbiological limit of TMAB at the end of the storage period of 90 days in the refrigerator. However, fermented seabass sausage reached the maximum level of YM count on the 10th day of storage, whereas fermented trout sausage reached this level on the 30th day of storage. Therefore, it is suggested that they should be packaged in vacuum packaging because of preventing too much drying and the growth of undesirable moulds. Additionally, the identification of microorganisms in fermented fish sausages would also be advised to determine desirable and undesirable microorganisms. Dry fermented fish sausage would be an alternative product to traditional dry fermented meat sausage in Turkey because of the health benefits of fish.

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