Frequency Response Analysis of Power Transformers

Abstract

Research has indicated that with increasing penetration of non-renewable energy sources, more and more high-frequency (HF) transformers are needed at the distribution level. Various new topologies have been proposed for this, one of them being solid-state transformers. HF transformers have also been proposed to be useful in micro-grids. The high integration of renewable energy sources need a new approach, and the research community is looking toward a more robust high-frequency operation of transformers. The objective of the paper is to understand the changes in characterization of magnetic circuit, along with skin effect and proximity effect of winding in HF transformers by measuring the frequency response analysis (FRA) signature. This involves setting up the user interface using LabVIEW, generating PWM signals using TI microcontroller board and building an analog circuit, which can provide a smooth sinusoidal input to a transformer over a wide frequency range. The first part of the paper involves the introduction and overview of how the sweep FRA is usually done in industry. The next part of the report describes the methodology used for conducting experiments. This includes the description of step-by-step process that was taken to gradually build the frequency response analyzer on breadboard. The last part of the project gives the results that were obtained during the experiment.