IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE) e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 9, Issue 6 Ver. IV (Nov – Dec. 2014), PP 53-57 www.iosrjournals.org DOI: 10.9790/1676-09645357 www.iosrjournals.org 53 | Page SFRA, Detect Of Winding Deformation in Power Transformer Shivangi Rai 1 , (Prof.) N.P. Gupta 2 1 M .tech Student, EEE Department, Oriental Institute of Science & Technology Bhopal, RGPV University, M.P. India. 2 Professor, EEE Department, Oriental Institute of Science & Technology Bhopal, RGPV University, M.P. India. Abstract: The sweep frequency response analysis is extensively used technique for detect hidden fault and condition monitoring of power transformer. The operation is carried out by supply a low voltage signal of varying frequencies to the transformer windings and measuring both the input and output signals. These two signals give the required response of the ratio is called the transfer function of the transformer from which both the magnitude and phase can be obtained. Frequency response is change as measured by SFRA techniques may indicate a physical change inside the transformer, and then causes of fault identified and investigation is required for root cause analysis. Keywords: Sweep Frequency Response Analyzer Doble M5100, SFRA, Winding Deformation, Power Transformer, SFRA Traces I. Introduction This work proposes to detect short-circuit faults between two turns in a winding of a transformer & mechanical displacement. The transformer is considered to be a complex network of RLC components. Any form of physical damage to the transformer results in the changes of this RLC network. These changes are what we are looking for and employ frequency response to highlight these small changes in the RLC network within the transformer. For different frequencies of the RLC network offers different impedance paths. Hence, the transfer function at each frequency is a measure of the effective impedance of the RLC network of the transformer. Any geometrical deformation changes in the RLC network, which in turn changes the transfer function at different frequencies and hence highlights the area of concern Power transformers are the most expensive and important component in a high voltage electric power system. It is one of essential elements and a failure of transformer can cause serious problems in electric utility operation. [11]. II. Sweep Frequency Response Analyzer The SFRA consist of measuring the impedance of a transformer winding over a wide range of frequencies & comparing the results with a reference set. SFRA is non-destructive test, Off-Line testing and it can be carried out for any voltage rating of Power Transformer. The measurement of SFRA can be a part of regular transformer maintenance. The SFRA Analyzer detects the following fault in the power transformer before break down occur. 1. Displacement of Core 2. Deformation and displacement of winding 3. Faulty core ground 4. Partial winding collapse 5. Hoop Buckling 6. Broken or loosened clamping structures 7. Shorted turns and open winding. The technique of SFRA is a major advance in transformer condition analysis. This is a tested technique for obtain precise and repeatable measurements. The test can be carried out, 1. First to obtain initial signature of the transformer sweep frequency response as a record for the future reference comparison. 2. Periodical measurement as a maintenance check, once in two years. 3. Immediately after a major external shortcuts, especially for faults electrically closer to transformer. 4. Transportation or re-location of transformer. 5. Earthquakes. 6. Pre-commissioning check.[1]