Abstract
M.Ing. (Electrical & Electronic Engineering)
The emphasis is currently. on improving the performance and operational costs of
compensators rather than finding new topologies. In the light of improving the operational
costs of a compensator, a thorough knowledge of the losses in the compensator is required.
This thesis analyses the losses in two commonly used compensators : the static VAR
compensator (SVC) and the dynamic compensator. The dynamic compensator is then
further subdivided into voltage-fed (VFC) and current-fed (CFC) dynamic compensator
categories.
Two processes are employed in this thesis: the instantaneous measurement of current and
voltage to calculate the power losses and the subsequent modelling of these losses. As a
first step the necessity for these loss-models are investigated by researching the extent to
which these types of compensators are employed in practical power networks for the
compensation of power factor and for harmonic elimination.
This study then progresses to investigate the validity of the formula used to calculate power
losses. Errors are always encountered when measuring signals and performing calculations
on these measurements. These errors are studied and mathematically quantified. In the past
various errors have been made in developing loss models for compensators. Some of these
errors are investigated in this thesis.
To enable the correct modelling of the losses in the various individual components of
.compensators, the operation of these compensators must be understood. This is done and
attention is given to the particular operational environments within which these components
operate. The literature is then surveyed to find loss-models which are most appropriate for
these conditions. In some instances existing models are adequate, while in others certain
refinements are made, and in still others new loss-models are developed. It is out of these
new models that the frequency-dependent inductor model is developed. This model can be
used in any environment where voltage and current harmonics are present...