Abstract
M.Ing. (Engineering Management)
The turbo-generator unit is very important equipment for electric power production, which
has a high rate of failure. As the capacity increases, condition monitoring and fault diagnostic
play a crucial role to guarantee safe operation and cost efficiency. The Eskom generator
fleet is fast approaching the end of the original designed life. Also in view of the recent
constrained reserve margin, outage downtime, maintenance costs, resource management,
and maintenance inherent problems, a systematic approach is required to optimise
scheduled time-based maintenance to improve reliability and availability.
The subject of turbo machine condition monitoring requires the development of new
technologies to diagnose the turbo-generator problems. Condition is an underlying factor in
the performance of machines. It is also an important predictor of future performance that the
machine is in a good condition and will be reliable and perform better. It provides a reference
for maintenance engineers on the current condition of the turbo-generator. Trends in
condition monitoring can be used to determine whether turbo-generators are being
maintained and that are meeting their expected service lives or whether their performance is
deterioration faster than expected.
In the industry, traditional maintenance philosophies have taken two approaches; the first
approach is to perform fixed time interval maintenance, where the system engineers take
advantage of relaxed production cycles to fully inspect all aspects of the turbo-generator.
The second route is for engineers to simply react to the generator failure as and when it
happens. All too many utilities operate largely in the reactive run-to-failure mode. The old
phrase, “if it aren’t broken don’t fix” is perennial run to failure argument. Nonetheless, making
use of today’s technology, a new scientific methodology is becoming popular to maintenance
management.
For the purpose of investigating the management of condition-based monitoring and
diagnostic technology to optimise timed-based maintenance of large turbo-generators,
Eskom Units installed with condition monitoring techniques were considered. The minidissertation
culminated in the compilation of case histories based on Eskom turbo-generator
fleet where the technology is being rolled out. The literature survey looked at current industry
practices in areas such as total productive maintenance (TPM), technology management
and support systems, return on investment (ROI) and maintenance management to compare
what Eskom is doing to what in others in the field are doing. There is no research work
currently that has been done that links maintenance to maintenance technology deployment
enablers. The research incorporates a number of operational experiences where some
Eskom turbo-generator units continue to operate with a known fault. Regular maintenance interventions introduce faults into the machine due to human error, the opening of units and
the handling of components. Attention is given to the impact of two-shifting or cyclic
operation on turbo-generators that were originally designed for base load condition. The
time–based maintenance of these units is not taking advantage of condition monitoring
information. Also, the installed condition monitoring techniques fall short of addressing twoshifting
monitoring requirements.
A number of lessons were learnt from the implementation of the condition-based
maintenance technology on Eskom generator fleet. The theory of maintenance management
underscores establishment of a good relationship between system engineers, maintenance
personnel and the technology provider which is key to success of the technology. It further
indicates that this relationship must go deeper than the mere technology provider and the
end user of the technology service agreement. The maintenance engineers are taking key
business decision for the well-being of machines and maintenance technology needs to
demonstrate that it is creating value for the business. From the people perspective attention
is required to staff motivation and providing balanced job satisfaction, whilst ensuring that
employees feel part of an integrated organisation maintenance strategy rather than of being
under thread of disempowered by the technology.
A myriad of considerations have been identified to affect the effective execution of conditionbase
maintenance strategy on Eskom generator fleet. There are multiple dashboards or
standards indicators that can be used for maintenance management improvement. It has
been established that the success of the implementation of condition-based maintenance
rests in the concept of total productive maintenance approach. Within the ambit of TPM, the
entire process of maintenance must be managed on the basis of maintenance programmes
plan, which will have function of connecting the various maintenance programmes.