Transformer, voltage ratio, vector group, impedance, short circuit impedance, load losses. Jun 18, 2012 the determination of vector group of transformers is very important before connecting two or more transformers in parallel. Threephase transformers can have their windings connected in various ways. Measure the voltage between the primary and the secondary terminals. The primary windings are connected in one of several ways. The power transformer connection type, the vector group and the subtraction of zero sequence currents onoff are setting parameters from these the differential protection calculates offline the matrix coefficients, which are then used in the online calculations. Vector group is punched on the name plate based on the user requirement by the manufacture. Nov 05, 20 connections for dy11 and dy1 transformers and the corresponding vector groupings are given in figure. For parallel operation of transformers the essential requirement is that the transformer connections belong to the same main group.
The two transformers may have their windings connected in starstar and yet it will not be possible to operate in parallel if one belongs to group 1 and the other to group 2, unless the internal connections of the secondary winding of one of the transformers are changed. Significance of vector group of transformer your electrical. The typical result for the vector group test of a ynd1 transformer is shown in fig. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. Consider primary side phases as r, y and b and corresponding secondary phases are r, y and b. Jun 24, 2015 the vector group of transformer is an essential property for successful parallel operation of transformers. The determination of vector group of transformers is very important before. Codefree, selfmaintaining browser tests w datadog synthetics. Winding polarity is also important, since reversing the connections across a set of windings affects the phaseshift between primary and secondary. Which side tapings of a transformer are provided and why. The clock method is used to produce the numerical index of the vector group. How do i draw vector group of transformer from winding connection. It must be pointed out that a single measurement on a transformer typically.
Understanding vector group of transformer part 1 the primary windings are connected in one of several ways. The clock method is used to produce the numerical index of. The performance parameters of interest can be obtained by solving that circuit for any load conditions. 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. I was lucky because the transformer ratio testset 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. From a vector group one can determine the phaseshift between primary and secondary. Liggett group llc founded in 1873, liggett group llc is the fourthlargest cigarette manufacturer in the u. Liggett group llc tobacco and new valley llc real estate, including douglas elliman. Performing transformer vector group test prepared by ir kamarul ariffin yahya uptp27 lead electrical engineer p27 amt supervisor. Transformer pd and induced voltage withstand test system. The supervisor will check that all the necessary tools and equipments to be used for testing are available in the testing area. A wide variety of vector group transformer options are available to you, such as power, electronic, and high frequency. Insulation power factor testing of power transformers.
The vector group of transformer is an essential property for successful parallel operation of transformers. What should we do if the prv trips in a transformer. Pdf performing transformer vector group test kamarul. Training on vector groups of transformer presented by.
The primary windings are connected in one of several. Why are the u1 of hv and u2 of the lv side of a transformer in the dyn11 vector group test. The type tests of the transformer confirm the main and basic design criteria of a production lot. The power transformer used to transfer the high voltage supply from one place to another. A grounding transformer with built in local power supply can be used as a local transformer. The determination of vector group of transformers is. Vector group test of power transformer electrical mastar. On a 11kv system, why would somebody use a transformer with a vector group dd0 over dyn11. Three phase transformers electrical engineering department. Howard lorber has served as the companys president and chief executive officer since 1994. The transformer vector group is indicated on the name plate of transformer by the manufacturer.
The testing engineer will instruct the supervisor regarding the testing works and will arrange for all necessary schematic drawings, data sheets and test formats to be available at the testing area. 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. I have faceting problem in testing of transformer vector group dy11y11y11y11, 380vx433000v for solar plant i have ask to client for factory. Material made available on the website is proprietary and vector group. After, installation of power transformer, several precommissioning tests to be done before putting the transformer in service. Interpret the vector group notations used on transformer name plates content.
Transformer vector group connections are made based on the winding polarity. Why are ynd1ynd11 the most common vector groups for power. Points to be consider while selecting of vector group. Power transformer vector group test cr4 discussion thread. Mainly, the type of transformer connections are divided in 4 below groups. Silsbee contents t page introduction 317 generalprinciples 318 nullmethod 321 deflectionmethod 325 experimentalresults. Dec 12, 2017 vector group test, check the voltage phase shift of two or more transformer. 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. Understanding transformer vector groups transformer vector groups can be a difficult concept to understand.
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. Dec 22, 2017 description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. Hv side delta,lv side star 1 connect hvside with 3 phase supply, 2 short with a cable hv r phase. Common precommissioning tests of transformer insulation resistance values of various winding should be checked. Dy connection y winding nullifies 3rd harmonics, preventing it to be reflected on delta side. The equivalent circuit parameters areavailabletothedesigner ofthetransformers.
Vector group test of transformerthe vector group of transformer is an essential property for successful parallel operation of transformers. It consists of a capital and small letter plus a code number. The power factors of transformers filled with envirotempfr3 fluid are usually higher than similar transformers filled with mineral oil power factor testing is more common for power than distribution class transformers and ieee c57. Windings can be connected as delta, star, or interconnectedstar zigzag. Vector group of transformers transformer electric power. Transformer is the most important unit in an electrical distribution network. Owing to adherence to international quality norms and customer services, tesla. Please give the detail procedure of vector group test with the example of. Understanding transformer vector groups valence electrical. All transformers are subjected to various tests at the manufacturer. In this way you can measure the vector group of any 3 phase transformer. Vector group test, check the voltage phase shift of two or more transformer. Transformers connected in parallel must have the same vector group mismatching.
Transformer vector group the vector group test is importent test in the transformer testing. How to draw vector group of transformer from winding. The determination of vector group of transformers is very important before connecting two or more transformers in parallel. Aim of vector group test is at site is to check if their is any damage in the windings. Different grounding transformers vector group zn vector group ynd open five limb. What are the advantages or benefits of using a yyno vector group transformer over other types of transformer vector groups. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. If two transformers of different vector groups are connected in parallel then phase difference exists between the secondary of the transformers and large circulating current flows between the two transformers. Vector group test of power transformer electrical4u. Now apply 415 vincrease the voltage gradually to limit the current in between ryb. Ive a practical way to check the vector group of a 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. Download fulltext pdf power factor testing of drytype transformers article pdf available in regions magazine 1114 april 2012 with 536 reads. The vector group transformer test is important for connecting two power transformer in parallel.
Labelling the windings in this transformer as high voltage, low voltage and tertiary, the schematic consists of six components, namely. Thanks for reading about significance of vector group of transformer. If 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. Description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. 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. Connections for dy11 and dy1 transformers and the corresponding vector groupings are given in figure. Sep 26, 2017 the vector group transformer test is important for connecting two power transformer in parallel. Pdf transformer vector group test conditions k pandian. Separate singlephase transformers can be used and externally interconnected to yield the same results as a 3phase unit.
The simplified schematic diagram of a three winding transformer is shown in figure 5. According to iec764, the value of vector group can be 0,1,2,4,5,6,7,8,10,11. The following requirements shall be fulfilled depending on the vector group of the transformers. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Vector group of 3phase transformer electrical concepts. The three phase transformer is connected in various ways. The transformer vector group show the phase difference between the primary and secondary sides of the transformer.
Swedish neutral also offers five limb ynd open connected grounding transformers, suitable for neutral grounding of smaller industry grids. If we want to connect two transformer in parallel then their phase shift should be same, otherwise there will be a. Vector group test of transformer testing of transformer. Importance and elimination of third harmonics application and selection of vector group of transformer. Along with different precommissioning tests, different instruments associated to the transformer also to be checked. Introduction to vector group the vector group marks the circuitry of windings and their phase position to each other. Vector groups are the iec method of categorizing the primary and secondary winding configurations of 3phase transformers. The phase sequence or the order in which the phases reach their.
Hi, all the transformers in a subtransmission network are dyn11, in another part of the network a transformer with the vector group of ynd1 is going to be used for an industrial complex. But after the winding connection is made it is necessary to check if the desired vector group has been achieved. Type tests are done mainly in a prototype unit not in all manufactured units in a lot. Vector group in transformer pdf economical home lighting. The phase sequence or the order in which the phases reach their maximum. Effective maintenance test techniques and diagnostic. The connection group is defined only for threephase transformers. Parmar, while i appreciate your article on significance and selection of vector group of transformers, pl.