Abstract
M.Ing. (Engineering Management)
Looking at the economic and technological growth of South Africa 50 years back until now, it is
evident that electricity is very essential. The need of a reliable power distribution system has grown
tremendously in this decade. The majority of the households and businesses rely on the functions of
electric appliances and equipment to assist with daily tasks such as cooking, bathing, etc. The
objective and function of Eskom is to ensure that electricity is delivered to every household and
business in the country; hence, due to the rapid social development in areas such as Soweto, the
distribution network operates under the pressure of being reliable against the odds of the network.
This dissertation describes a methodology for reliability enhancement of distribution network
system by calculating the reliability indices such as SIADI, SAIFI and RSLI in order to determine the
improvements that can be done to the distribution network using the reliability based methodology.
These indices indicate the performance of the system relative to its reliability namely the frequency
of failures; the number of failures and the average rate of failures in the distribution system
(includes feeders, reclosers, transformer, fuses, etc.). The problem of distribution system failure in
Jabulani, Soweto has been decomposed in two stages. The first stage determines the optimum
failure rates and the second stage optimizes repair times satisfying constraints. Identifying potential
for power failure cost reduction through extended parts life of the system, reduced maintenance
labour cost, and other parts of the network-related improvement techniques are essential in
reducing the power constraints. The implementation of reliability based method in planning and
design of capital changes in network layout is done to ensure full maintainability of equipment and
utilities.
Customer and energy based reliability indices are important to evaluate predictive performance of
distribution network system. A case study of demand energy in Jabulani, Soweto has been presented
to evaluate optimum failure rate and repair time for each section so as to achieve desired reliability
goals in terms of the mentioned indices. Applying this reliability method helps in monitoring the
distribution network feeders and consequently, improving its reliability.