Abstract
D.Ing.
In this thesis, contactless power transmission with sliding transformers to mobile
loads is investigated. The sliding transformer comprises an extended primary
winding - placed along the path of travel - which is fed through a core containing
a secondary winding and which is attached to a mobile load. In the first chapter
problems with existing power supply systems are discussed whereafter several
possible applications of such a system are identified. In this chapter different
methods of obtaining contactless power transmission are also discussed and a brief
discussion of a practical, cost effective system is given. In chapter two the
application of different resonant topologies to compensate the large structural
inductance of the sliding transformer is investigated. A Series Resonant, Series
Loaded topology is identified as the most practical and efficient topology for this
application and a more detailed analysis of this topology - as applied to this case -
is given. Formulas to calculate the sliding transformer parameters are given in the
third chapter and two quantities relating the optimization of sliding transformers to
the parameters thereof, are defined. Methods to optimize sliding transformers in
terms of these two quantities, and also with respect to EMI, are also discussed in
this chapter. The design of a five meter long experimental system which delivers
15 kVA to a mobile load is given in chapter four and experimental results of this
system are presented. In chapter five a detailed investigation into different output
power control methods is conducted. The effect of these control methods on EMI
is investigated by means of numerical simulation of a Series Resonant, Series
Loaded system under these different control methods. The most complex control
method which generates the most EMI, namely frequency and pulse burst control,
is implemented into the experimental system to investigate the limitations thereof.
Experimental results of this controlled system are presented. It is found that this
control method increases the control range obtainable with classical frequency
control but introduces many limitations due to discontinuous primary current. It is
concluded in the last chapter that it is possible to optimize sliding transformers
within achievable cost constraints to such an extent that such systems have
acceptable efficiencies and that reasonable system lengths are obtainable.