Pdf protection of power transformer using microcontroller. Impedance dc winding resistance megger and power factor windings, bushing and arrestors. If you do not have any voltage at the heater winding of the power transformer when it is in the circuit but it measured ok when it was out of the circuit, something is loading and pulling down the voltage. Bpa has hundreds of power transformers installed throughout the system, and. Routine tests and type tests of transformers electrical4u. As it checks the quality of material used and the procedure of transformer manufacturing hence provide us details of life of transformer, the transformer behaviour on different faults. It is also done at site to ensure healthiness of a transformer that is to check loose connections, broken strands of conductor, high contact resistance in tap. As such it is desirable to perform various preventative maintenance activities to ensure the transformer maintains a high level of performance and a long functional life. The following should be expected on chl power factors. Assume, for the sake of simplicity, that the core of an isolation transformer has only two windings in the window area, a primary and a secondary. In my place, we are having two transformers and the first one is 3311 kv and the second one is 110. The authors gratefully acknowledge the assistance of all who. Power transformers are vital components of the power supply infrastructure. The ai techniques include artificial neural networks ann, or briefly neural networks nn, expert systems, fuzzy systems and multivariate regression.
In addition, power transformer outages have a considerable economic impact on the operation of an electrical network. The ac hv test value should not surpass 75% of the factory test value. Aug 09, 2017 in this post, i will discuss how to troubleshoot the power transformer in your real life that i am doing now with our two power transformer. If the ttr test does not pass, then the transformer is usually not returned to service. Transformers tutorial this piezo tutorial provides a basic introduction to piezoelectric transformers. This test also performed as a routine test of transformer. Basics, maintenance, and diagnostics vii contents continued page 4. The main components of the applied voltage test system will be installed either in the test field for factory testing or on an 11m. The geometry of the magnetic circuit is three dimensional. A power transformer is the most costly and essential equipment piece of equipment within an electrical substation. Check colour of active agent if silicagel is pink, change by new charge. The amperage rating for your transformer fuse may be labeled on the transformer. Routine tests are carried out on every unit manufactured. Iribution is unlimited power transformer maintenance and acceptance testing.
This dissertation is a systematic study of artificial intelligence ai applications for the diagnosis of power transformer incipient fault. All transformers are subjected to the following routine tests. Consult transformer manufacturers or test equipment. Threephase rectifier, safety power transformer for 24vdc, 80adc supply with rc load. Power transformers represent the largest portion of capital investment in transmission and distribution substations. As power transformer is highly expensive as well as important part of distribution system. Low inrush current universal control power transformer, 800va,50hz. Testing and diagnostics of power transformers brochure 4. Impulse test concepts by philip j hopkinson, pe strong clues to field problems. Mainly two types of transformer are done by manufacturer before dispatching the transformer mainly 1 type test of transformer and 2 routine test. In this article, you will learn different types of transformer testing methods, test setup, and their acceptance criteria.
By brandon dupuis an introduction to electrical diagnostic. Kirubakaran2 research scholar 1, assistant professor2 abstract ower transformer is one of the most imperative equipments in a high voltage electric power system. Scribd is the worlds largest social reading and publishing site. The objective of testing is to ensure quality to ensure that the products manufactured have met the requirements of customer specificationstandard to prevent accidents which may occur if a failed product is put into service. The ratio of an instrument transformer is the relationship of its primary rating to its secondary rating. Diagnostic testing solutions for power transformers. Ba c 104 fundamentals of power electronics chapter 15. Lorin, methodology for life assessment on power transformers,trafotech2002, sixth international. More often, transformer losses are limited by a maximum hot spot temperature rise at the core surface inside the center of the windings. For more spe cialized applications, the principles discussed herein.
Complete power transformer portfolio abb offers a complete range of power transformers and related components and parts. It is carried out as a type test as well as routine test. Voltage transformer testing swp page 3 of 19 standard work practice sp0508 ver 7 ergon energy corporation limited abn 50 087 646 062 if any risks cannot be managed or reduced to an acceptable level, do not proceed with the task and seek assistance from your supervisor. Test this by hooking up the secondary to its circuit and using your dmm to test the secondary lines. The purchase, preparation, assembly, operation and maintenance of transformers represent a large expense to the power system. Oct 03, 2016 the type and routine test are very important for transformer.
The potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. Instrument transformer basic technical information and. Wait until 24 hours after completion of oil filling for power factor testing. Our power transformers are manufactured with a rated capacity of between 5 and 100 mva and for service voltages of up to 245 kv. To ensure that the product is fit for its intended use standards iec standards iec 60076 part 1 part 14. A power transformer requires various routine maintenance. Highly oscillatory windings to impulse and chop wave tests 2.
There are various test required on transformer to conform performance of transformer. Choose secondary turns according to desired turns ratios. The power transformer testing fat test is performed after completion of the assembly at the manufacturing shop. Testing power transformers highvoltage transformers are some of the most important and expensive pieces of equipment required for operating a power system. In this post, i will discuss how to troubleshoot the power transformer in your real life that i am doing now with our two power transformer. Power transmission and distribution author page 244 200708. The power equation equation 4 applies to each winding of the transformer.
So for ensuring proper performance of electrical power transformer, voltage and turn ratio test of transformer one of the important tests. Power transformer troubleshooting an electrical engineer. Transformer testing has developed considerably over the past years. Full text of power transformer maintenance and acceptance testing see other formats. Transformer basic objective introduce basic transformer theory as it relates to diagnostics provide a better understanding of the diagnostic test environment identify important information that should be collected in the diagnostic test process. Transformer ct testing as test equipment becomes more sophisticated with better features and accuracy, we risk turning our field personnel into test set operators instead of skilled field service technicians. All work to be done with voltage transformer deenergised. Twowinding transformers have terminals designated by h and x e. The standard for maintenance testing specifications for electrical power equipment and. Tm 5686 power transformer maintenance and acceptance. How do you test a power transformer that is disconnected. A comprehensive and interactive online transformer condition monitoring system integrates all relevant main components of the power transformer within only one system fig.
Power transformer faults identification using sfra t. T m 5686 headquarters departmen t o f th e army washington, dc, 16 novembe r 1998 approved for public release. Various influences can impact the expected lifetime. Cables connected at lv cable box, feedin g the load of the connected power system. Artificial intelligence applications in the diagnosis of. H 1, h 2, x 1, x 2, where h is the higher voltagerated winding and x is the lower voltage winding.
Testing of power transformers seems like a similar experience. If that voltage is ok, look for an open between the transformer and the heater pins on the first tube. When ac hipot tests are used for routine maintenance, the power transformer can be examined at rated voltage for 3 min instead of testing at 65% of factory test voltage. Protection of power transformer using microcontrollerbased relay conference paper pdf available february 2002 with 4,094 reads how we measure reads. Rectifier safety power transformer for feed to voltage controllers of 5vdc, 1adc and 2x12vdc,0. The primary windings of the potential transformer are directly connected to the power circuit whose voltage is to be measured. Specification substation power transformer standard number. Back to the basics current testing valence electrical. Ch and cl power factor or dissipationfactor values will vary due to support insulators and bus work utilized on dry transformers.
Output power, p0, is of the greatest interest to the user. Lack of damping in the circuit sfra determination of transformer natural frequencies are clues but not directly relatable to field performance 1. To the transformer designer, the apparent power, pt, which is associated with the geometry of the transformer, is of greater importance. Based on this, the tutorial describes vital elements of the piezo transformer such as electrical equivalent circuit, soft switching and the longitudinal mode transformer. Power and accuracy the cpc 100 cp td1 can measure capacitance and pf df tan d in laboratories, test fields and on site. Mar 29, 2019 confirm the proper input to the transformer. Tm 5686 power transformer maintenance and acceptance testing. May 10, 20 so transformer ratio test is an essential type test of transformer. If the measurement is less than 80 percent of the expected voltage, the fault could lie in either the transformer or the circuitry providing the primary with power. Transportation, erection, testing and commissioning. Flyback transformers actually coupled inductors are covered in a later section. Nov 17, 2019 a power transformer is the most costly and essential equipment piece of equipment within an electrical substation.
To adapt the voltage, it is possible to provide onload tap changers for max. Terminal marking of power transformers is determined by ansi standards. C electrical power from one voltage to another voltage keeping the frequency same by electromagnetic induction discover the worlds research 17. Page 1 of 14 standard work practice sp0504 ver 4 ergon energy corporation limited abn 50 087 646 062. Testing of three phase power transformer ijireeice.
Page 1 of 14 standard work practice sp0504 ver 4 ergon energy corporation limited abn 50 087 646 062 ergon energy queensland pty ltd abn 11 121 177 802 1. During commissioning and operation it is essential that your power transformer is in good condition. A test set operator connects the leads, pushes the buttons, and records the results. Power transformer factory test using ieee standards. Power transformer testing power transformer factory test using ieee standards waldemar ziomek cg power systems canada ieee training, houston, texas, oct. For example, the potential transformer mentioned above having a rating of 480. Thereby a correlation of all data of the transformer or even of several transformers is possible. In addition some other tests are also carried out by the consumer at site before commissioning and also. The database and all algorithms are located on only one ied. Low power factor circuits at the point of switching 3. The type and routine test are very important for transformer. Taking the sum of the voltsamp va products for each winding of an winding transformer va 5 the window utilization factor is the ratio of the total conduction area to the total window area and therefore 6 the current density in each winding is, where.
Use the dmm in ac mode to measure the transformer primary. Transformer loss is sometimes limited directly by the need to achieve a required overall power supply efficiency. We have delivered more than 14,500 power transformers over 17,000,000 mva, including over twenty 800 kv uhvdc and over five hundred 735765 kv ac units, to all major global markets. This transformer step down the voltage to a safe limit value which can be easily measured by the ordinary low voltage instrument like a voltmeter, wattmeter and watthour meters, etc. Maintenance of transformers a detailed checklist electrical4u. An electrical power transformer has to go through a number of transformer testing procedures for confirming its specifications and performances. Potential transformer pt definition the potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. In this book we have laid down important aspects on transformer. Ensure adequate lighting is provided in the working area at night time. Ensure only trained persons shall operate the power tools. One of the most important parameters governing a transformers life expectancy is the hotspot temperature value.
If the reading is above the amperage rating for the transformer, the circuit is drawing too much power. Power transformer design this section covers the design of power transformers used in buckderived topologies. Current transformer, simplified equivalent circuit. Transformer basic objective introduce basic transformer theory as it relates to diagnostics. The potential transformer is connected in parallel with the circuit. A polemounted transformer on a power distribution line is vulnerable to lightning overvoltages, and is one of the most frequently damaged instruments in japan. Power transformers built for reliability and efficiency. Pdf power transformer li tests with high frequency pulse. Pdf power transformersprinciples and applications book. Temperature rise c equals thermal resistance cwatt times power loss watts.
The procedure of the transformer ratio test is simple. Ensure all concerned personals shall use ppe and all other items as required. Transformers are the largest, heaviest and often the costliest of circuit components. Power transformer testing swp check this is the latest process zone version before use. Power transformer design examples and applications by rale. It evolved from the simple gonogo verdict into a sophisticated segment within transformer manufacturing. Ensure service areawork area openings are provided with barricade, tape, and safety nets. Power rated 500 kva and above between generation and distribution gsu generator stepup, autos, transmission class xfmrs autotransformers. The fault free operation of a power transformer is a factor of major economic importance and safety in power supply utilities.