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. Therefore, the cpc 100 is the ideal test set for substation asset commissioning and maintenance. How to draw vector group of transformer from winding. 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. 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, jytf transformer turn ratio tester has this function. In a transformer, when we increase the load on the secondary side, how does the. The three phase transformer windings can be connected several ways. Transformer vecttransformer vector group test conditionsor group test conditions free download as pdf file. Transformers built to ansi standards usually do not have the vector group shown on their nameplate and instead a vector diagram is given to show the relationship between the primary and other windings.
Why vector group of distribution transformer is dyn11. The clock method is used to produce the numerical index of the vector group. Transformer is the most important unit in an electrical distribution network. Sep 26, 2017 the vector group transformer test is important for connecting two power transformer in parallel. Turning vector diagram into vector group is essential and necessary before making the test. A vector group is the international electrotechnical commission iec method of categorizing the high voltage hv windings and low voltage lv winding configurations of threephase transformers. Significance of vector group of transformer on the nameplate of threephase transformer vector group is printed as yy 0, dd 1 etc. The letters indicate the winding configuration as follows. The phase sequence or the order in which the phases reach their maximum. The standard test usually links the a and a terminals then applies a suitable safe test voltage to the hv winding, and the resulting voltages between terminals prove the vector group. May, 2019 download version download 8 file size 424. May 04, 2018 to perform transformers parallel operation without seeing the winding connection, the manufacturer mentions the transformers vector grouping to avoid accidental faults. The vector group designation indicates the windings configurations and the difference in phase angle between them. Transformer check of vector group the purpose of this series of tests is to check the polarity and the phase relationship of the multiple windings in a transformer.
Type tests are done mainly in a prototype unit not in all manufactured units in a lot. Jun 29, 2018 understanding transformer vector group transformer is magnetically coupled circuit its primary and secondary voltages either in phase or out of phase to say them in phase or out of phase will all depend upon polarity considerations before to discussing polarity we will see something about notational basics of electricity 3. Basic idea about transformer vector group in theory of a threephase transformer works like three equal and separated singlephase transformers working separately with three phase system with shared limbs. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. Aim of vector group test is at site is to check if their is any damage in the windings during transportation and erection. It also determines the high voltage and low voltage windings arrangement of three phase transformers. Through vector group of a transformer we can know that the winding configuration of a transformer. The vector group check can be used to determine the vector. The vector group of transformer is an essential property for successful parallel operation of transformers.
If you are replacing a transformer, use the same vector group for the new transformer, otherwise the existing vts and cts used for protection and metering will not work properly. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. The three stage transformer windings can be joined a few ways. Know the condition of your transformer to get the most out of your asset. Vector group test of transformer the vector group of transformer is an essential property for successful parallel operation of transformers. Hv side delta,lv side star 1 connect hvside with 3 phase supply, 2 short with a cable hv r phase. The vector group of transformer is the phase difference between the primary and the secondary sides. Applicationnote how to determine transformer vector group. For example, a wye hv winding and delta lv winding with a. Transformer vector group test conditions ynd1, ynd11, dyn11, ynyn0 and. Cpc 100 universal primary injection test set for substation.
This was done in order to create a notation for threephase transformer winding configuration. Nov 05, 20 vector group test is done in order to know the phase displacement between the high voltage and low voltage winding. Vector group test of power transformer electrical mastar. If the two transformers of different vector groups are connected in parallel then phase difference exist between the secondary of the transformers and large circulating current flows between the two transformers which is very damaging. Transformer, voltage ratio, vector group, impedance, short circuit impedance, load losses. The harmonics in a transformer are present only in the transformer inrush current predominantly 2 nd harmonic content. Introduction to vector group the vector group marks the circuitry of windings and their phase position to each other. The determination of vector group of transformers is very important before. The naming convention popularly known as vector group of transformer was established by the international electrotechnical commission iec through iec 600761. Vector group test of power transformer electrical4u. The clock method is used to produce the numerical index of the vector group, with each hour representing 30.
There is no technical difference between the one vector groups i. Power transformer vector group testing by voltage method. Three phase transformer vector grouping significance. Vector group test of power transformer electrical study. Vector group test of power transformer electrical study app. The vector group of a transformer defines the connection of the hv and lv windings. One procedure of vector group testing of transformer is explained as below. It consists of a capital and small letter plus a code number. The transformer vector group show the phase difference between the primary and secondary sides of the transformer. Transformer vector group the vector group test is importent test in the transformer testing. Significance of vector group of transformer your electrical. Ratio and vector group test for trafo electric power. The capital letter a, b, c refers to the hv winding and the lower case a, b, c to the lv winding with a, b, c for.
You can operate the cpc 100 via the integrated front panel, or by using. Performing transformer vector group test prepared by ir kamarul ariffin yahya uptp27 lead electrical engineer p27 amt supervisor. Assuming the reader has sufficient exposure to transformer winding connections. How do i draw vector group of transformer from winding connection. Here the magnetic circuit for the two outer limbs of the three phase transformer is lit bit longer than for the center limb of the same. The determination of vector group of transformers is very important before connecting two or more transformers in parallel. Understanding transformer vector groups valence electrical. Understanding transformer vector groups transformer vector groups can be a difficult concept to understand. Autotransformer vector group cr4 discussion thread.
Dec 12, 20 the transformer vector group is indicated on the name plate of transformer by the manufacturer. Threephase transformer connections and vector groups for. The vector group transformer test is important for connecting two power transformer in parallel. The transformer vector group is indicated on the name plate of transformer by the manufacturer. First, connect the test power supply to high voltage winding. Vector group of transformer technology for volt and current.
I was lucky because the transformer ratio test set i used for the first couple of years in my career allowed me to make threephase connections, but it was really a singlephase tester and i had to change the connections one phase at time. What is the use of transformer vector group dyn11 in tamil. What is the test procedure of vector group of a transformer having vector group dyn11. 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. What is meant by vector group for transformers and why is it. Understanding vector group of transformer part 1 the primary windings are connected in one of several ways. Heat run test iec 600762 excitation current measurement. How to determine transformer vector group dv power. Winding resistance measurement iec 600761 turns ratio measurement iec 600761 oltc analysis iec 602141 transformer demagnetization. Dec 22, 2017 description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. 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.
In electrical engineering, a vector group is the international electrotechnical commission iec method of categorizing the high voltage hv windings and low voltage lv winding configurations of threephase transformers. Vector group test of transformerthe vector group of transformer is an essential property for successful parallel operation of transformers. Here yy 0 will mean its both the windings are starconnected and phase displacement between primary and secondary emfs is zero degree. Why are ynd1ynd11 the most common vector groups for power. All transformers are subjected to various tests at the manufacturer.
A transformer will be of either coretype or shelltype construction, and typical forms of construction are shown in figs. This reduces the costs for training and transport, and cuts down testing time. Transformers built to ansi standards usually do not have a vector group shown on their nameplate and instead a vector diagram is given to show the relationship between the primary and other windings. These tests are done when the tap of transformer is nominal. In the system adopted by the iec, the vector group is indicated by a code consisting of two or three letters, followed by one or two numeric digits.
Vector group is punched on the name plate based on the user requirement by the manufacture. The vector group provides a simple way of indicating how the connections of a transformer are arranged. What is the significance of vector grouping in power. In light of the windings association, the vector gathering of the transformer is resolved. Transformer vector group detection archives dv power. The patented cpc 100 primary injection test system replaces several individual testing devices. Transformer testinf part3 ratio test and vector group test. This cannot be avoided by selecting a tansformer with a particular vector group. Rphase hv and rphase lv shorted for all vector group of transformer.
Pdf performing transformer vector group test kamarul. Vector group test of transformer is done for detecting the vector group. Vector group of 3 winding transformer cr4 discussion thread. The three phase transformer is connected in various ways.
Transformer vecttransformer vector group test conditionsor group. The type tests of the transformer confirm the main and basic design criteria of a production lot. The test is carried out simultaneously with the transformer turns ratio test when using a turns ratio test set. Understanding transformer vector group linkedin slideshare. How do you identify the primary winding of a stepdown power transformer. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. Transformer vector group connections are made based on the winding polarity. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. The vector group designation indicates the windings configurations. Transformer vector group free download as powerpoint presentation. Pdf transformer vector group test conditions k pandian. But after the winding connection is made it is necessary to check if the desired vector group has been achieved.
1347 1527 562 1120 1391 1442 752 495 938 123 1017 114 982 398 646 1390 1425 1285 630 1476 369 743 369 200 1387 1125 902 645 1129 34