Pasanduka, Timothy (2017) A study of sweep frequency response analysis in power transformers. Coursework Masters thesis, University of Southern Queensland. (Unpublished)
Abstract
A power transformer is an important asset in the generation, transmission and distribution of electrical energy. In some power utilities, the voltage is generated in the range 18 kilovolts (kV) to 22kV. In order to transmit the generated power with high efficiency, the voltage has to be stepped up to high values. This reduces the current and hence the losses. In Australia, the highest transmission voltage is 500kV. After transmission, the voltage has to be stepped down to safe values that can be used at the local load centres. Transformation of these voltages is done by a power transformer. It is therefore important that a power transformer used in generation, transmission and distribution of electricity be sound, safe and healthy to use.
Faults on a power system can have impacts on power transformers that are connected to the grid. The severity of damage depends on the fault current and how long it lasts. A power transformer is designed to withstand faults up to the design level, faults beyond the design limit can result in damage that may or not be re-parable. It is critical that any fault on the transformer be detected and cleared on time. Sweep frequency response analysis (SFRA) is used to analyse certain transformer faults that can not be detected by routine tests or other transformer tests.
Sweep frequency response analysis is based on analysing the transfer function of a network of connected units. One such system is the power transformer which has a network of passive electrical components which are connected together to form a unique system. In a healthy state, a sweep frequency test is done and the results are stored. After an event such as a power system fault or natural phenomena like an earthquake, the same test is repeated and results compared. Any deviation will denote a problem. It is often difficult to interpret the results of a sweep frequency test whenever differences occur in the plots of response curves. This project is destined to analyse the results of a sweep frequency test so that a clear understanding of the fault can be drawn.
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| Item Type: | Thesis (Non-Research) (Coursework Masters) |
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| Item Status: | Live Archive |
| Additional Information: | Current UniSQ staff and students can request access to this thesis. Please email research.repository@unisq.edu.au with a subject line of SEAR thesis request and provide: Name of the thesis requested and Your name and UniSQ email address. |
| Faculty/School / Institute/Centre: | Current - Faculty of Health, Engineering and Sciences - No Department (1 Jul 2013 -) |
| Supervisors: | Das, Narotam; Helwig, Andreas |
| Qualification: | Master of Engineering Science (Power) |
| Date Deposited: | 16 Jul 2026 04:37 |
| Last Modified: | 16 Jul 2026 04:37 |
| Uncontrolled Keywords: | power transformer, electrical energy, high transmission voltage |
| URI: | https://sear.unisq.edu.au/id/eprint/53259 |
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