Transformers and their component parts are critical to the reliable and uninterrupted functioning of all electric power systems. In order to increase availability of critical circuits and to optimise operational management, condition monitoring of power transformers is not only useful, but is fast becoming essential, since utilities are constantly facing the need to reduce costs that are associated with the operation and maintenance of the installed equipment. Condition monitoring equipment that is used to extend the life of a transformer or to prevent catastrophic failure could pay for itself many times over in the lifetime of the apparatus to which it is fitted. Nevertheless, condition monitoring does not come free of charge, and utilities have tight budgets that have to be met. To determine best value for money, life-cycle costing must be applied to each chosen application. The life cost comes from the summation of the installation, the maintenance, the repair and the lifetime operational costs of the equipment. Several options of monitoring equipment covering a wide spectrum of costs are readily available and others are under development. Monitoring equipment that looks at one or two specific parameters is readily available in the marketplace at modest cost. At the other end of the cost spectrum, not only can many parameters be monitored, but an expert system or artificial intelligence system that is capable of generating an estimate of the overall plant condition may be used to interrogate the data and draw conclusions and recommendations. There are several such integrated systems on the market, such as the MS 3000 supplied by Alstom Grid.

Chapter Contents:

• 20.1 Introduction
• 20.2 How do faults develop?
• 20.3 Which parameters should be monitored?
• 20.4 Continuous or periodic monitoring
• 20.5 Online monitoring
• 20.6 Degrees of sophistication for transformer monitors
• 20.7 What transformer parameters can be monitored?
• 20.8 Basic monitors
• 20.9 On-load tap-changer (OLTC) module
• 20.10 Insulation module
• 20.11 Bushing module
• 20.12 Cooling module
• 20.13 Advanced features measurements and analyses
• 20.14 Partial discharge monitoring
• 20.15 Temperature measurement
• 20.16 Chemical parameters
• 20.17 Dielectric parameters
• 20.18 Conclusions
• 20.19 Further reading
• References

Inspec keywords: life cycle costing; fault diagnosis; condition monitoring; power transformers

Other keywords: plant condition; electric power systems; critical circuits; power transformers; catastrophic failure; operational management; life-cycle costing; integrated systems; condition monitoring; artificial intelligence system; monitoring equipment

Subjects: Plant engineering, maintenance and safety; Transformers and reactors