Sfra test on transformer pdf in word

Pdf statistical approach for interpretation of power. Anytime a transformer is moved there is a possibility of damage to this transformer. In addition some other tests are also carried out by the consumer at site before commissioning and also periodically. Test your sfra instrument and leads together or test the instrument using the included hook up cables. An electrical test procedure for determination of copper sulfide contamination in transformer windings lance r. The latest sfra test sets make these techniques more accessible, more convenient and. In 2012 the transformer was again subjected to sfra test. Response analysis sfra test for the identification of faulty or incipient faults in power transformers 2, focusing mainly on the identification of factors which alter the test and that there is no answer to get correct frequency responses of the same for interpretation. Sfra testing basics offline test the transformer is seen as a complex impedance circuit open excitation current and short shortcircuit impedance responses are measured over a wide frequency range and the results are presented as magnitude response curves filter response changes in the impedance can be. Sweep frequency response analysis electrical test equipment. By using the latest proven sfra test techniques, it is possible to accurately assess transformer condition without dismantling it. Sweep frequency response analysis sfra for the assessment of. This test configuration is intended to check the response due to the influence of space between two windings in a particular phase.

Frequency response transformer testing sfra all about. The winding of transformer may be subjected to mechanical stress. Sweep frequency response analysis test or in short sfra test can detect. An initial sfra test is carried out to obtain the signature of the transformer frequency response by injecting various discreet frequencies. This is a case where a sweep frequency response analysis sfra test will become invaluable. Fra test is carried out on a healthy transformer to validate simulation results.

This paper presents how interpretation of sweep frequency response analysis sfra traces can be done for the open circuit and short circuit winding faults on the 10 kv a power transformer. Abb trafositetesting is the transformer test floor that comes to your site the abb tres mobile highvoltage power transformer test system enables abb tres to perform a full range of testing on all types and brands of transformers, reactors, cables and other hv equipment. Pdf on site oil test for a transformer using sweep. In this paper the method of sweep frequency response analysis sfra has been proposed for on site and instant test of oil condition without requiring the transformer to be opened and sending oil. All other terminals of the transformer left floating. This is also true for other, especially mechanical, faults. Typically, a baseline is taken in the factory to which all subsequent test results are compared. Abb trafositetesting is the transformer test floor that comes to your site the abb tres mobile highvoltage power transformer test system enables abb tres to perform a full range of testing on all types and brands of transformers, reactors, cables and other. Feb 23, 2012 if a good reading is found the transformer is good. This reference is then used for future comparisons. The measurement of sfra can be a part of regular transformer maintenance. The current installer available for download occupies 288. The transformer to be tested must be completely isolated from the power system. Theoretical considerations while applying sweep frequency.

If a good reading is found the transformer is good. It detects winding defects and faults in the magnetic core thereby helping to improve transformer reliability, reduce maintenance costs and prevent costly failures. The sweep rate response analysis is wide used technique for establish veiled fault and circumstance observance of power electrical device. Basics, maintenance, and diagnostics vii contents continued page 4. It is also known as iovtinduced over voltage test, it is one of the routine test of transformers usually performed to check in turn insulations of the windings. It measures the frequency response of passive element rlc of the apparatus. Sweep frequency response analysis test sfra test electrical4u. The sweep frequency response analysis sfra is an analysis technique for detecting winding displacement and deformation among other mechanical and electrical failures on power and distribution transformers. Non typical fault detection in power transformers using sfra. This includes methods to determine if the corrosive sulfur. Dismantling a power transformer to determine its condition is hardly ever a practical possibility.

Download limit exceeded you have exceeded your daily download allowance. Sfra and additional transformer test results to get a comprehensive overview of. Main core deformation, open circuits, shorted turns, residual magnetism. Nowadays, there is an increasing interest in sfra method because of its sensibility in detecting mechanical faults without opening the unit. Sfra, detect of winding deformation in power transformer. Each frequency range corresponds to dfferent components in the transformer. Sfra sweep frequency response analysis, leakage reactance, and normal power factor measurements were.

Before proceding with transformer measurements the test engineer will become familiar with the safety rules of section 2. Lewand, doble engineering company introduction over the past several years there has been much work performed to determine if an oil has corrosive sulfur present. In this paper the method of sweep frequency response analysis sfra has been proposed for onsite and instant test of oil condition without requiring the transformer to be opened and sending oil. This highlyaccurate verification device confirms that your equipment is providing you with results you can trust. Connect the test lead bnc connectors to the frax instrument, generator yellow, reference. This test is very reliable for condition monitoring of physical condition of transformer windings. Sweep frequency response analysis test or in short sfra test can detect efficiently, displacement of transformer core, deformation and displacement of winding, faulty core grounds, collapse of partial winding, broken or loosen clamp connections. Pdf measurement of shortcircuit effects on transformer winding. Based on the theory of the previous chapter, a value of remanent magnetization was minimal. Jan 08, 2019 sfra stands for sweep frequency response analysis. As per iec specifications, test should be carried out by applying double the r. Sweep frequency response analysis sfra for the assessment. Substation services saber power services substation. The test methods used by the authors for presenting the results are described.

Now, transformer was out of operation only for 24 hours. In this test configuration, input test signal is applied to one end of a winding and the response is measured at one end of another winding on the same phase. For example, valves positioned incorrectly, plugged radiators, stuck temperature indicators and level gauges, and noisy oil pumps or fans. Sweep frequency response analysis sfra is one of the most powerful diagnostic tools for assessing. Sweep frequency response test in the most of the commercial sweep frequency response measuring instruments, the measuring task is. To get value from an sfra test it is necessary to make sure that the measurements are credible, which requires good test technique and simple procedures. In other words, the admittance of the chosen circuit model would be very low and. The megger technical library provides access to a range of additional content and resources such as technical guides, application notes and more.

A sfra open circuit test will show the response of core and windings, while a sfra short circuit test only shows the response of windings. In a power transformer it measures the fault current of the winding over a wide range of frequencies. The latest sfra test sets make these techniques more accessible, more convenient and more dependable that ever. Following is an approximate sequence for transformer testing. Mainly two types of transformer are done by manufacturer before dispatching the transformer mainly 1 type test of transformer and 2 routine test. Sfra is condition monitoring technique for expensive power equipment. Expert system for sweep frequency response analysis of.

For instance, sfra method employs frequency span ranging few hertz to. The power transformer of rating 10 kva, 1 v440 v, 3phase, 50 hz, dyn11 has been specially developed inhouse for carrying out sfra testing by. Sfra 5000 is a standalone sweep frequency response analyzer for the high accuracy transformer analysis and integrates the sts and td 5000 family test sets. A measurement setup accompanied by a transformer as a test object, on which winding faults are imposed, completes the test setup for performing the fra measurements. That time, transformer was out of operation for almost 9 months. Most dielectric and mechanical failures in large power transformers are.

Sfra and additional transformer test results to get a. Result analysis and reporting after the measurement a reference test of the same. An electrical test procedure for determination of copper. To test a transformer with a digital multimeter dmm, first turn off power to the circuit. Use the dmm in ac mode to measure the transformer primary. The power transformer of rating 10 kva, 1 v440 v, 3phase, 50 hz, dyn11 has been specially developed in house for carrying out sfra testing by. The action is administrated by provide a coffee voltage signal of changeable frequencies to the electrical device windings and measures each the input and output signals. Sfra is an off line testing and it can be carried out for any voltage rating of power transformer, generator transformer and distribution transformer. Measurement of shortcircuit effects on transformer winding with sfra method and impact test. Power transformer, internal faults, frequency response analysis, maintenance and condition monitoring, sweep frequency response analyser. Experimental investigations to identify sfra measurement. The most popular versions among the software users are 3. Next, attach the leads of your dmm to the input lines.

The doble m5150 can be used in the field or in the office allowing you to isolate problems between hardware and cables. Our antivirus analysis shows that this download is malware free. The endtoend sfra connection is one of the most commonly used connections of the sfra test. The power transformer of rating 10 kv a, 11,000 v440 v, 3phase, 50 hz, dyn11 has been specially developed inhouse for carrying out sfra testing by. Sfra and the role it plays in transformer test and maintenance. If the measurement is less than 80% of the expected voltage, your problem could be with the transformer or the circuitry providing the. Transformer service trafositetesting verify the reliability. Sweep frequency response analysis given below is a list of sweep frequency response analysis projects executed by us. Interpretation of sweep frequency response analysis sfra. According to 3 sfra method determines the transformer responses in a time or frequency area. In all cases the specimen under test transformer, reactor, etc. It has been developed with the assistance of bureau of reclamation engineers. Request pdf sweep frequency response analysis sfra for the assessment.

A change in winding position, degradation in the insulation, etc. There are various test required on transformer to conform performance of transformer. Sfra is an electrical test that provides information relating to transformer. The sfr analyzer identifies the following abnormalities in the. To improve the quality of your regular inspection program. It is useful to correlate the two methods to increase the precision of the result. What is the correct procedure for dvdf and hv test on. Sfra, detect of winding deformation in power transformer doi. Frax sweep frequency response analyzer sfra is designed to detect. Sfra testing on transformers dismantling a power transformer to determine its condition is hardly ever a practical possibility. The latest version of the software can be downloaded for pcs running windows xpvista. Nov 17, 2019 sweep frequency response analysis test or in short sfra test can detect efficiently, displacement of transformer core, deformation and displacement of winding, faulty core grounds, collapse of partial winding, broken or loosen clamp connections, short circuited turns, open winding conditions etc.

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