Power transformers are one of the most valuable and important components of the power system. Due to their high value and long service life, reliable diagnostic methods are required to operate them. Transformer diagnostic is necessary to help avoiding the malfunctions of the power system and to minimize the operational costs.
Different kinds of diagnosis and inspection technologies are applied to prevent from transformer failure in power systems. For example, examination of internal Partial Discharge of transformer, analysis of transformer oil gas (Dissolved Gas Analysis), and measurement Frequency Response Analysis are used to diagnose defects.
Dissolved Gas Analysis (DGA) is widely used for monitoring faults in high voltage electrical equipment in service. And, Frequency response analysis (FRA) is a powerful and sensitive tool to assess the core, windings and structures in power transformer. In this paper I will describe the methods of assessing transformer and design the hardware of an FRA measuring device.