Much like a blood test in humans, the results of an online dga of the transformer oil reveal developments inside the transformer. Samples are generally sent to a laboratory for analysis but portable equipment is available to perform the. It is noted that the oil quality tests for transformer oil are inconclusive and that the dga test is then necessary. Analysis of a transformer oil sample for dissolved gases by a laboratory is an established technique recognised as the most important test for monitoring power transformers.
This test can give an early indication of abnormal behavior of the transformer. The published literature does not detail if arcing in a transformer can change stable sulfur species into reactive or corrosive forms. Reliabilitybased dga is a new method of dissolvedgas analysis interpretation, developed by deltax research. This paper uses dissolved gas analysis to study the history of different transformers in service, from which dissolved combustible gases dcg in oil are used as a diagnostic tool for evaluating the condition of the transformer. Prediction of dissolved gas concentrations in transformer oil. Pdf interpretation of dissolved gas analysis in transformer oil. Dga testing of transformers part 2 february 27, 2014 in part 1 of this twopart series on dissolved gas analysis dga and testing of oilfilled transformers, it was stated that dga evaluation of combustible gasses is used to determine possible causes of a transformers internal problem or fault. From this method, the validation and test set errors have the same characteristics and. These gases can be detected in transformer insulating oil using sensitive and. Dissolved gas analysis dga of transformer oil is one of the key methods of assessing transformer health 1. It is believed that there is room for improvement in combining svm. Fault severity is the core property in transformer maintenance. H 2 ch 4 c 2h 2 c 2h 4 c 2h 6 co tdcg avrg caution ppm. New frontiers of dga interpretation for power transformers.
Performing tests to evaluate the quality of the transformer oil. It can cause non availability of transformers for long hours. Tops is a set of specifications developed and maintained by the doble oil committee and is the basis for the annual oil survey testing. Dissolved gas analysis iec 60599 for many years the method of analysing gases dissolved in the. Dissolved gas analysis dga is a test used to assess paperoil insulation systems, and the most commonly used technique for oilinsulated power transformers. The dga test measures dissolved gases in the transformer oil and is capable of detecting. Dissolved gasin oil analysis the most important test that can be done on the liquid insulation of a transformer is an annual dissolved gas analysis dga.
Thus, a more intuitive approach is combining the results derived from all major test. Icmcompact dissipation factor and partial discharge measurement on cable. The condition monitoring tests includes ir, tandelta, magbalance, winding resistance, turns ratio, bushing tandelta, dga, oil bdv, etc. Gray transformer chemistry services introduction the fault free operation of power transformers is a factor of major economic importance and safety in power supply utilities and industrial consumers of electricity. Both industrial transformer users and utilities are setting up these planned sampling programs using online devices that can monitor the oil for quality. Acidity test of transformer insulating oil electrical4u. Transformer failures are often due to the lack of the dielectric strength of oil insulation and will. Myrkos is supplied with the ppmreport control and database management software. Service contract for carrying out the transformer oil. Morgan schaffer pioneered dissolved gas analysis dga in america. Sampling of transformer oil by syringe as per iec 60475. The oil used in transformers as coolant and insulator has gases dissolved in it due to aging and faults inside the transformer. What is the normal frequency of transformer oil sampling. Thus, by merging thermal stress in paper and oil, the resulting.
Practical experience gained from dissolved gas analysis at an. The effect of transformer aging on dissolved combustible gasses is also examined. Our 50 years of experience in transformer oil analysis guarantees precise and accurate analytical results. Small samples of oil are taken for this test, using a clean, moisturefree containersyringe. The distribution of these gases can be related to the type of electrical fault, and the rate of gas generation can indicate the severity of the fault. Guest editorial understanding dissolved gas analysis dga. Pdf oilimmersed power transformers condition diagnosis. Samples are generally sent to a laboratory for analysis but portable equipment is available to perform the test in the field. H2, o2, n2, co, co2, ch4, c2h6, c2h4 and c2h2 are analyzed. These two key points are essential when interpreting the dga results for distribution transformers. Main purpose of the the oil in a tank is to be an insulator.
Transformer oil testing petroleum transformer free 30. This glass system involves a vacuum pump with mercury vacuum gauge. In general, the solubilities and thermal decomposition products of beta fluid are very similar to those from conventional transformer oil. Opt100 is the worlds first maintenance free multigas dga monitor. Dec 06, 2012 dissolved gas analysis dga of power transformer oil shivaji choudhury 2. Pdf evaluating the accuracy of different dga techniques for. Transformer oil gas analysis cont manual sample handing. If a transformer is overloaded for a long period of time, the deteriorating condition of the cellulose will shorten the life of. Power transformer diagnostics, monitoring and design.
This reaction is accelerated by exposure to light, therefore sampling devices made of transparent materials i. Power transformers, in order to assess the condition of windings, insulation, core, transformer oil. To optimize cost and performance, hybrid insulation materials combining. Pdf residual life assessment with dga, furan content in. The oil sample is analysed in the laboratory using gas chromatography technique. With its individual and modular system components mte provides the optimal customer oriented solution for utilities, industries and transformer manufacturers. Different dga techniques for monitoring of transformers. The risk of failure of transformers in service, based on dissolved gas analysis dga, depends on three main parameters. Much attention is needed on maintenance of transformers in order to have fault free electric supply and to maximize the lifetime and efficacy. After the first year, an annual dga test should suffice.
The standard test suites are designed for individual samples to deliver a routine set of oil analysis at low cost. The kelman transport x is a compact portable dissolved gas analysis dga system which can be used to analyze oil samples for all dissolved fault gases and moisture. The dga will require the removal of an oil sample from the transformer and this can be done without deenergization of the transformer. Optimus dga monitor opt100 for power transformers online monitoring. More importantly, an oil sample can be taken at any time from most equipment without. Insulating materials within transformers and electrical equipment break down to liberate gases within the unit. Jun 19, 2017 the dga test measures dissolved gases in the transformer oil and is capable of detecting. A dga test can identify an overloaded transformer by a test result showing high carbon monoxide, high carbon dioxide, and in extreme cases, even elevated methane and ethylene. Dissolved gas analysis dga technique is commonly used to identify. Variations of type 1 transformers may exist pending past records and age of units. Reliabilitybased dga quick start guide for toa4 users. Regular sampling and testing of insulation oil taken from transformers is a valuable technique in a preventative maintenance pr ogram. Importance of transformer processes the way a transformer is handled and the procedures that are used to receive, assemble, process and test the transformer are of fundamental importance to the long life of the transformer.
Power transformer fault severity estimation based on dissolved. Transformer monitoring mte meter test equipment ag. Valve option 752 automate two valves 78900047 configured per. Dukarm deltax research inc 20060320 transformer dissolvedgas analysis dga is the measurement of gases dissolved in the insulating fluid of a transformer, and the interpretation of the measurement data so obtained, in combination with other information about the transformer and its environment. Identification of transformer fault based on dissolved gas. Over time and due to electrical stresses and thermal decomposition, the cellulose paper and insulating mineral oil in paperoil insulation systems break down and forms gases which are dissolved in the oil. Astm d3612 test methods for analysis of gases dissolved in electrical insulating oil by gas. Nov 15, 20 gc2010d measures dissolved gases in transformer oil. About 4 years back we have also started carrying out sfra sweep frequency response test. Whenever a transformer undergoes abnormal thermal and electrical stresses, certain gases are produced due to the decomposition of the transformer oil. With dga, samples are taken of the oil s exhaust gases to determine if any events have occurred that might be detrimental to the transformer and reduce its life. Oil quality and dissolved gasses tests are comparatively used for this purpose. Gases generate by degradation of fluid or cellulose. Monitor and maintain transformer oil during its service life.
Detects most internal faults, some external faults and some operational errors. Dissolved gas analysis dga is a diagnostic tool that used to detect the incipient faults of power transformers through the correlation between the content of gases dissolved in transformers oil and a particular malfunction. It is the first indicator of a problem and can identify deteriorating insulation and oil, overheating, hot spots, partial discharge, and arcing. The dga requires routine oil sampling and modern technologies for online gas monitoring. Dissolved gas analysis guide for transformers filled with.
The use of dissolved gas analysis dga as a method for determining the. Type 3 transformers in this category show signs of serious fault gas concentrations or. Dga is accustomed to detect elementary faults in the transformer. Optimising the future management of large transformers on networks to maximise the utilisation and full potential life of existing transformers and to ensure. Dissolved gas analysis dga is the study of dissolved gases in transformer oil insulating materials within transformers and electrical equipment break down to liberate gases within the unit. As the concentration of dissolved gas in transformer oil has always been in a state of dynamic. Solomon corporation dga testing of transformers part 2. Astm d3612a 15 gas chromatography for the energy industry july 17, 20. Product information dissolved gas analysis and supervision. Optimus dga monitor opt100 for power transformers online. By combining various dga techniques and interpreting classical dga with fuzzy logic system approach, we have increased the predictability of. Type 2 this category covers any transformer showing test results where some concern is evident re test recommended in six months. It is noted that the oil quality tests for transformer oil are inconclusive and that the dga test is then necessary for complete evaluation of transformer condition. Oil diagnostic suites for transformer oil diagnostics.
Dissolved gas analysis dga in transformer condition monitoring dissolved gas analysis is a method of monitoring the condition of electrical transformers and related oil filled equipment. Many companies use the doble transformer oil purchase specification tops and the annual oil survey to qualify oil suppliers, using these materials as independent assessments of commercially available oils. In this method a sample of the oil is taken from the unit and the dissolved gases are extracted. The installation and testing of the transformer verifies its. Dga values of transformer oil prc electrical 12 jan 09 01. Practical experience gained from dissolved gas analysis at an aluminium smelter ian. Color d1500 the color of a new oil is generally accepted as an index of the degree of refinement. The technique explained above can be used to detect and determine fault gases at the desired trace ppm levels. Dissolved gas analysis iec 60599 for many years the method of analysing gases dissolved in the oil has been used as a tool in transformer diagnostics in order to detect incipient faults, to supervise suspect trans.
This provides you with a reliable status diagnosis of your transformer at any time during operation. Dga results of oil samples drawn from transformers of different. Therefore, you dont want to have a water in your transformer because water is a very good conductor and could cause a partial discharge. Requires 1 litre of oil in a polyethylene container provided by src. Oil diagnostics test information for both financial and operational reasons it is very important that transformers are managed efficiently. It is very important that a dga sample is kept airtight.
Background dissolved gas analysis dga is the most important tool in determining the condition of a transformer. Introduction transformer is one of the most important but complex component of electricity generation and transmission system. The above standard testing is offered in specific diagnostic suites designed to provide the maximum condition information on the transformers. The doble materials laboratory performed experiments in which a voltage of 25 kv was applied to sustain an arc through cross oil crosstrans 106 transformer oil in a test cell equipped with a needle to.
What should be the water content in transformer oil, and. They can now be applied to transformers filled with beta fluid. Mte offers a broad range of products and solutions for the online gasin oil monitoring of transformers online dga. Product information dissolved gas analysis and supervision of. Dga approaches the dga 18 is among the most common techniques used for online incipient fault diagnosis because the transformer need not be deenergized.
Ge grid solutions kelman dga 900 installation manual. The operation is fully owned and operated by bhp billiton. Dga has become a standard in the electrical maintenance industry throughout the world and is considered to be the most important oil test for transformer oils in electrical apparatus. School of engineering, department of electrical engineering, blekinge institute of technology, s371 79 karlskrona phone. While in service transformer undergoes various termal,chemical,electrical stresses due to that some gases generated these gases known as fault gases which r quantitified in extremely low level in parts per million ppm, the test which is conducted to analyse these fault gases known as dga test. Then the extracted gases are separated, identified, and quantitatively determined. Exclusively for consultation by member of the ieee transformer committee 3152006 proposed gas level correlation between each level limit and the % of dga population below the limit. They are the vital links between generation and transmission. Dga after application of 100 breakdown tests in the oil samples. If a proactive approach is adopted based on the condition of the transformer oil, the life of the transformer can be extended. Transformer oil introduction transformer oil is like a blood in human body. White paper applying dissolved gas analysis to distribution.
Advantages of the togatransformer oil gas analyzerinvolving. The myrkos portable dga microgc is used with morgan schaffers shake test syringe to analyze oil samples within two minutes. In 30 bayesian methodic has been used to combine expert judgment and avail. At present this entire technique is best done in the laboratory since it requires. The most sensitive and reliable technique for evaluating the health of transformer is dissolved gas analysis dga.
Once power transformer is charged and commissioned, transformer oil becomes a key element to monitor the healthiness of unit and dga is one of the important tools to predict probable fault developing in unit as well as analyse insipient trippings. For oils in service, an increasing or high color number is an indication of contamination, deterioration, or both. Gc2010d measures dissolved gases in transformer oil. The acidity of insulating oil is generally measured by the required quantity in milligram of koh to entirely neutralize the acidity of a specific quantity in gram of the oil. Dissolved gas concentration limit for interpretation of fault level as per ansiieee.
Much in the same way that a doctor can analyze a patients blood to determine certain health problems, the trained transformer owner can detect problems within the. As the name implies, this test analyzes the type and quantity of gases that are dissolved in the transformer oil. This reliabilitybased dga quick start guide is documentation to help toa4 users understand and use new software features relating to reliabilitybased dissolvedgas analysis r dga for oil filled power transformers. Pdf influence of transformer oil aging byproducts on the. Pdf evaluating transformer condition using dga oil analysis. Assessing remnant life of transformer based on furan.
Comprehensive multigas dga for your critical power transformers comprehensive multigas dga for your critical power transformers the vaisala optimus dga monitor gives you out of the box performance and offers the best longterm stable measurements with no maintenance. Diagnostic tool for transformer fault detection based on. Dga, of a very healthy transformer and a transformer with severe fault are discussed. Oilimmersed power transformers condition diagnosis with. Evaluating transformer condition using dga oil analysis. The dissolved gas analysis can give an early indication of abnormal conditions inside the transformer. Yes the results show over heating of oil with out any arcing or involvement of cellulose. Newly installed transformers should be sampled frequently within the first 12 months i. The dga test analyzes the gas concentrations that are dissolved in the transformer oil. Dga tests results from 38 power transformers in a developing country and will propose a maintenance decision making procedure using the iec 605992007 and duvals triangle. The hillside aluminium smelter is located in richards bay, 200 kilometers north of durban, kwazulunatal province, south africa. In case of a manual operating mode, the oil samples are first injected into a vacuum.
Condition monitoring of power transformers using dissolved. Experimental investigations on the dissolved gas analysis method. Performance of natural ester as a transformer oil in moisturerich environments. Dissolved gas analysis dga is the study of dissolved gases in transformer oil. Designed for both the new user and experienced equipment operator, ppmreport is available in six different languages. The fault types cases that are provided have been chosen by combining. Transformer oil analysis testing service for monitoring the condition of transformer oils routine testing of transformer insulating oil is an essential maintenance function that ensures a safe working environment and helps eliminate the possibility of disrupted production resulting from a transformer failure or explosion. Classical dga systems falls under astmd3612 method a, and utilize a glass system with mercury for dissolved gas extraction from transformer oil 2. This product information is divided into the following sections.
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