ENGINEERING

Dedicated to Lee-Anne Hamilton A prototype data acquisition and processing system is developed for evaluating the insulation condition of a power transformer winding in real-time. The Transformer Insulation Condition Monitoring System (TICMS) evaluates the insulation condition by calculating the winding trans admittance function. The winding transadmittance function is used to fingerprint the insulation system and provides a means of monitoring its condition. The use of a transfer function for evaluating the insulation condition of a power transformer winding was proposed by Malewski and Poulin in 1988 [6, Chapter 1]. The work described in this thesis extends their work in a number of important areas and makes the following contributions to the state-of-the-art. Firstly, the TICMS is able to calculate the trans admittance function to 3MHz, which is sufficient to detect breakdown between individual turns in an Extra High Voltage (EHV) transformer. This is a key distinguishing feature of this work and is important as faults between individual tumscan quickly snowball into a catastrophic failure. Previous attempts have been successful at determining the transadmittance function to around 1.5MHz, whic