Transformer vector group depends upon removing harmonics. This was a topic brought up on the job and i figured i would address it in a very general post. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. The power transformer used to transfer the high voltage supply from one place to another. Mainly, the type of transformer connections are divided in 4 below groups. Note that when determining the angle between h1 and x1, the rotation must be clockwise.
This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. The vector group of a transformer does not change the power flow of a system. There are several internal connections of threephase transformer are available on the market. I believe most 3 phase textbooks have the vector diagram with the reference vector at 0 degrees on the xaxis, which would equate to. The clock method is used to produce the numerical index of the vector group. Harmonic analysis of power transformer vector groups. An ordinary transformer consists of two windings called primary winding and secondary winding. Performing transformer vector group test prepared by ir kamarul ariffin yahya uptp27 lead electrical engineer p27 amt supervisor. The vector group transformer test is important for connecting two power transformer in parallel. Type of cooling onan onan the voltage level can be specified as 415240 v400230 v volts as per the requirements of the purchaser. This was done in order to create a notation for threephase transformer winding configuration. Description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge.
To conduct a performance test whether the transformer is faulty or not, a given low voltage of about the single phase value vphv l 3. The following will tell you the suggestions with reasons. It is sometimes also indicated on the name plate of the transformer. The phase sequence or the order in which the phases reach their maximum. The vector group test vg is performed in a very similar fashion as the ttr test just that it has to be performed by injecting a balanced three phase voltage, i. The vector group can be determined from the connection of the winding. But after the winding connection is made it is necessary to check if the desired vector group has been achieved. Basically, the power flow is the steady state condition of the system and therefore must assume that all transformers.
The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Ratio and vector group test for trafo electric power. Transformer vecttransformer vector group test conditionsor. Transformer vector group dyn11 and dyn1 physics forums. Ive a practical way to check the vector group of a transformer. Vector group of 3phase transformer electrical concepts. Dy1 would hence be a delta primary, wye secondary and a vector diagram with the reference vector pointing at 1 oclock.
By joining cr4 you can subscribe to this discussion and receive notification when new comments are added. Consider primary side phases as r, y and b and corresponding secondary phases are r, y and b. Recall that most modern differential relays internally compensate the currents it sees based on the transformer vector group. Through vector group of a transformer we can know that the winding configuration of a transformer.
The typical result for the vector group test of a ynd1 transformer is shown in fig. Transformer vector group free download as powerpoint presentation. Join cr4, the engineers place for news and discussion. Vector groups are the iec method of categorizing the primary and secondary winding configurations of 3phase transformers. This will not go too in depth but will help you understand how a vector is configured and possibly understand what you are dealing with on the job. The first letter d refers to the primary configuration being a delta connection the y refers to the secondary configuration being a star connection. Aim of vector group test is at site is to check if their is any damage in the windings during transportation and erection. Transformer testing type tests and routine tests of. By far the most common vector configuration of three phase transformers we manufacture is the dyn11 vector group. Testing of power transformers seems like a similar experience. Mib202 relay, which can be used to operate for internal faults, like.
All transformers are subjected to various tests at the manufacturer. Performance test of faulty distribution transformers along. As i red from my college for vector group yd11 we have. It also determines the high voltage and low voltage windings arrangement of three phase transformers. Transformer, voltage ratio, vector group, impedance, short circuit impedance, load losses. Siemens persons performed ratio and vetor group test with eqiupment. Hence every electrical power transformer must undergo through vector group test of transformer at factory site for ensuring the customer specified vector group of transformer. If we want to connect two transformer in parallel then their phase shift should be same, otherwise there will be a. From your question above, i presume that ur understanding of the transformer is not complete. Transformer is the most important unit in an electrical distribution network. The transformer vector group show the phase difference between the primary and secondary sides of the transformer. The two most common configurations are the delta, in which the polarity end of one winding is connected to the nonpolarity end of the next, and the star, in which all three nonpolarities or polarity ends are connected together.
The phase sequence or the order in which the phases reach their. The primary and secondary windings of the transformer may be connected in either by. What is the test procedure of vector group of a transformer. From a vector group one can determine the phaseshift between primary and secondary. Vector group vector groups are method of categorizing the primary and secondary winding configurations of 3phase transformers and the phase relation between primary and secondary. Liggett group llc tobacco and new valley llc real estate, including douglas elliman.
Proper vector grouping in a transformer is an essential criteria for parallel operation of transformers. Power transformer vector group test cr4 discussion thread. Vector group test of transformerthe vector group of transformer is an essential property for successful parallel operation of transformers. I have faceting problem in testing of transformer vector group dy11y11y11y11, 380vx433000v for solar plant i have ask to client for factory. In auto transformer two windings are not only magnetically. In theory a threephase transformer works like three separate. The transformer vector group is indicated on the name plate of transformer by the manufacturer.
Dec 12, 2017 vector group test, check the voltage phase shift of two or more transformer. In a 3 phas e transformer, it is essential to carry out a vector group test of transformer. Because a test confirms what you know, if you can apply in real life what you have learned in a classroom, under strict, rigorous and controlled conditions. Transformer vecttransformer vector group test conditionsor group. Understand significance of vector groups interpret the vector group notations used on transformer name plates content. May 23, 2012 the vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. Importance and connection diagram common vector group of transformers. Applicationnote how to determine transformer vector group. Importance and elimination of third harmonics application and selection of vector group of transformer. Vector group test of power transformer electrical4u. Transformer vector group connections are made based on the winding polarity. Transformer vecttransformer vector group test conditionsor group test conditions free download as pdf file.
The vector group of transformer is an essential property for successful parallel operation of transformers. Rphase hv and rphase lv shorted for all vector group of transformer. Audible sound levels decibels at rated voltage and frequency for liquid immersed distribution transformers shall be as below nema standards. The motor takes no load without coupling impller only 2. Vector group of 3 winding transformer cr4 discussion thread. Please note that u cannot have two different vector group on a single transformer,i.
Vector group test of transformer testing of transformer. According to iec764, the value of vector group can be 0,1,2,4,5,6,7,8,10,11. Why are ynd1ynd11 the most common vector groups for power. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. Windings can be connected as delta, star, or interconnec. Vector group test is done in order to know the phase displacement between the high voltage and low voltage winding. Pdf performing transformer vector group test kamarul. Sep 26, 2017 the vector group transformer test is important for connecting two power transformer in parallel. There are so many way to connect the three phase transformer windings. The naming convention popularly known as vector group of transformer was established by the international electrotechnical commission iec through iec 600761. Dec 22, 2017 description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. How does transformers vector group affect on power flow. Pdf transformer vector group test conditions k pandian.
The determination of vector group of transformers is very important before connecting two or more transformers in parallel. Vector group test, check the voltage phase shift of two or more transformer. Howard lorber has served as the companys president and chief executive officer since 1994. The mib202 is microcontroller based numerical biased differential protection relay with inbuild current amplitude and vector group compensation features and also with instantaneous differential highset element for two winding power transformer and autotransformers. Liggett group llc founded in 1873, liggett group llc is the fourthlargest cigarette manufacturer in the u. Vector group test of power transformer electrical study app. Vector group test of power transformer electrical study.
P department of electrical and electronics engineering loyola institute of technology and science loyola nagar, thovalai, tamilnadu629302, india abstract transformer is the most important unit in an electrical distribution network. Going counterclockwise between h1 and x1 can give wrong phase angle, and therefore wrong phase displacement number, which leads to wrong vector group and possibly to wrong test results. Vector group test of power transformer electrical mastar. Vector group is punched on the name plate based on the user requirement by the manufacture.
For example, in order to test the slope characteristic of the. These two windings are magnetically coupled and electrically isolated. In vector group primary winding connection should be shown in capital letter followed by next high voltage winding connection in small letters followed by phase. Dy connection y winding nullifies 3rd harmonics, preventing it to be reflected on delta side. The three phase transformer is connected in various ways. Understanding vector group of transformer part 1 the primary windings are connected in one of several ways.
Separate singlephase transformers can be used and externally interconnected to yield the same results as a 3phase unit. If these compensation factors are not applied correctly, the relay can produce erroneous results. Transformer vector group three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the same iron core. Without earthing the winding neutral points, interconnect one phase of hv winding say 1u to the corresponding phase of lv winding 2u and apply a balanced 3 phase low voltage to the hv winding.
But the transformer in which a part of windings is common to both primary and secondary is called auto transformer. Basically this vector group arrangement will define the physical displacement of the generator shaft and the electrical phase of. The clock method is used to produce the numerical index of. Dec 12, 20 from a vector group one can determine the phaseshift between primary and secondary. Assuming the reader has sufficient exposure to transformer winding connections transformer vector group test conditions ynd1, ynd11, dyn11, ynyn0 and more pandian. Hence every electrical power transformer must undergo through vector group test of transformer at factory site for ensuring the customer specified vector group of transformer the phase sequence or the order in which the phases reach their maximum. Effective maintenance test techniques and diagnostic. Material made available on the website is proprietary and vector group. Nov 05, 20 vector group test is done in order to know the phase displacement between the high voltage and low voltage winding. Without earthing the winding neutral points, interconnect one phase of hv winding say 1u to the corresponding phase of lv winding 2u and apply a balanced 3 phase low voltage to the hv.
1235 675 1213 225 1431 1311 800 1289 1520 414 1213 1469 643 973 194 1159 229 202 1113 595 921 236 1496 553 50 358 16 449 1020 1198 269 880 512 1026 275