The reliability and maintainability of the transmission transformers in South Africa
- Authors: Molabe P.P.
- Date: 2018
- Subjects: Eskom (Firm) , Electric transformers - South Africa - Maintenance and repair , Electric insulators and insulation , Electric power transmission , Electric power supplies to apparatus
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/286013 , uj:30941
- Description: M.Phil. (Engineering Management) , Abstract: The power utilities have the challenging task of supplying electricity and meeting stakeholders expectations with constrained resources. Like other power utilities, Eskom has a mandate of generating and distributing electricity in a safe, reliable and cost-effective ways. The success and failure of the South African power utility are depended on the capabilities of the transformers and the maintenance strategies adopted to support the systems. This study presents the finding of the reliability and maintainability analysis of the transmission transformers in Eskom from the period of 2014 to 2016. The study used statistical methods to analyse secondary data from Eskom operational records and reports. During the period of analysis, Eskom experienced twenty-nine failures related to transmission transformers. The study shows that Eskom was operating with the ageing transmission transformers, the protection system and bushings came out as dominating causes for malfunctions. It is recommended that Eskom change the maintenance strategy and focus on replacing the high failing component or systems to improve reliability.
- Full Text:
- Authors: Molabe P.P.
- Date: 2018
- Subjects: Eskom (Firm) , Electric transformers - South Africa - Maintenance and repair , Electric insulators and insulation , Electric power transmission , Electric power supplies to apparatus
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/286013 , uj:30941
- Description: M.Phil. (Engineering Management) , Abstract: The power utilities have the challenging task of supplying electricity and meeting stakeholders expectations with constrained resources. Like other power utilities, Eskom has a mandate of generating and distributing electricity in a safe, reliable and cost-effective ways. The success and failure of the South African power utility are depended on the capabilities of the transformers and the maintenance strategies adopted to support the systems. This study presents the finding of the reliability and maintainability analysis of the transmission transformers in Eskom from the period of 2014 to 2016. The study used statistical methods to analyse secondary data from Eskom operational records and reports. During the period of analysis, Eskom experienced twenty-nine failures related to transmission transformers. The study shows that Eskom was operating with the ageing transmission transformers, the protection system and bushings came out as dominating causes for malfunctions. It is recommended that Eskom change the maintenance strategy and focus on replacing the high failing component or systems to improve reliability.
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Evaluating an empirical relationship between recloser placement and reliability improvement in distribution networks
- Authors: Thomas, Ponny
- Date: 2016
- Subjects: Electric networks , Electric power distribution , Electric power transmission , Eskom (Firm)
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/213003 , uj:21065
- Description: Abstract: The National Energy Regulator of South Africa (NERSA) has implemented an Incentive- Based Regulation (IBR) scheme that either rewards or penalizes distributors on the System- Average Interruption-Duration Index (SAIDI) and other network performance indices [1]. The optimal placement of automatic reclosers (auto-reclosers) is seen as a cost-effective measure to reduce the system-average interruption-duration index (SAIDI) impact along a medium voltage (MV) feeder. An auto-recloser is seen as a function of distribution automation (DA), thus reducing customer impact. A great advantage of a correctly implemented and operated DA system can improve network reliability significantly. This dissertation evaluates the empirical relationship between recloser placement and reliability from the perspective of control and instrumentation within ESKOM. It also puts forward an additional performance-improvement framework that can be implemented to achieve RAM (Reliability, Availability and Maintainability) management. Loop automation functionality is also under discussion; this is a Distribution-System Automation-scheme that restores the supply to the fault-free sections of a network, if they have been disconnected, because of a fault in another section of the network. Loop automation can also restore the normal network configuration automatically, when the faulty section is repaired. The process of isolating the faulty section and re-configuring the network to restore supply back to the fault-free sections is the first capability of Loop Automation. This research investigation assesses two different scenarios, namely: A conventional implementation of auto-reclosers on MV networks using Eskom reliability standard; and (ii.) the findings of a case-study using this recloser implementation (loop automation) to improve the reliability and the system’s performance. Results obtained are presented and discussed. , M.Phil. (Engineering Management)
- Full Text:
- Authors: Thomas, Ponny
- Date: 2016
- Subjects: Electric networks , Electric power distribution , Electric power transmission , Eskom (Firm)
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/213003 , uj:21065
- Description: Abstract: The National Energy Regulator of South Africa (NERSA) has implemented an Incentive- Based Regulation (IBR) scheme that either rewards or penalizes distributors on the System- Average Interruption-Duration Index (SAIDI) and other network performance indices [1]. The optimal placement of automatic reclosers (auto-reclosers) is seen as a cost-effective measure to reduce the system-average interruption-duration index (SAIDI) impact along a medium voltage (MV) feeder. An auto-recloser is seen as a function of distribution automation (DA), thus reducing customer impact. A great advantage of a correctly implemented and operated DA system can improve network reliability significantly. This dissertation evaluates the empirical relationship between recloser placement and reliability from the perspective of control and instrumentation within ESKOM. It also puts forward an additional performance-improvement framework that can be implemented to achieve RAM (Reliability, Availability and Maintainability) management. Loop automation functionality is also under discussion; this is a Distribution-System Automation-scheme that restores the supply to the fault-free sections of a network, if they have been disconnected, because of a fault in another section of the network. Loop automation can also restore the normal network configuration automatically, when the faulty section is repaired. The process of isolating the faulty section and re-configuring the network to restore supply back to the fault-free sections is the first capability of Loop Automation. This research investigation assesses two different scenarios, namely: A conventional implementation of auto-reclosers on MV networks using Eskom reliability standard; and (ii.) the findings of a case-study using this recloser implementation (loop automation) to improve the reliability and the system’s performance. Results obtained are presented and discussed. , M.Phil. (Engineering Management)
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