Contents hide 1 basic idea about transformer vector group 1. One procedure of vector group testing of transformer is explained as below. Asked in electrical engineering how do you test yyn0 vector group of transformer. Iam an electrical engineer working in aptransco, sir i want to know.
Subscribe our electrical engineering related channel electrical academy to. Vector groups are the iec method of categorizing the primary and secondary winding configurations of 3phase transformers. Vector group test of power transformer electrical study app. Primary and secondary must be star, with zero vector group phase shift, because there is no other way to use auto transformers on 3 phase. So it is utmost necessary to know how the inter connections to be made to form a particular vector group. It means lv winding,which is star connected written in small letters means lv. The vector diagrams are given in the name plate details of the transformer. Vector group in transformer pdf economical home lighting. Name of the department electrical engineering subject code2 name of the subject electrical. The vector group transformer test is important for connecting two power transformer in parallel. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. Understanding vector group of transformer electrical engineering. Based from this, we can say that this transformer connection belongs to the vector group ynd11. Based on the windings connection, the vector group of the transformer is determined.
The harmonics in a transformer are present only in the transformer inrush current predominantly 2 nd harmonic content. So it is utmost necessary to know how the inter connections to be made to. There is no technical difference between the one vector groups i. The transformer vector group show the phase difference between the primary and secondary sides of the transformer.
Significance of vector group of transformer on the nameplate of threephase transformer vector group is printed as yy 0, dd 1 etc. These tests are done when the tap of transformer is nominal. It consists of letters identifying the configuration of the phase windings and the number indicating the phase angle between the phasetoneutral voltages of the windings. Transformer vector group free download as powerpoint presentation. The first letter is capital letter which may be y, d or z, which stands for high voltage side star, delta or interconnected star windings respectively.
Threephase vector diagrams are commonly used to represent 3 phase transformers are known as transformer vector diagrams. For q1, there is no way to determine the vector group on a oneline diagram except when explicitly labled. Vector grouping of a three phase transformer part1. 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.
According to iec the code for vector group consist of 2 or more letters followed by one or two digits. 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. Vector group of 3phase transformer electrical concepts. Windings can be connected as delta, star, or interconnec. The determination of vector group of transformers is very. 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. Jun 18, 2012 from a vector group one can determine the phaseshift between primary and secondary. Vector group test of power transformer electrical4u.
Transformers connected in parallel must have the same vector group. Dec 22, 2016 our smart downloadable video courses are live at this video explains you the baisics of phasor grouping of a three phase transformer. This video contains vector grouping of three phase transformer for starstar and deltadelta connections. It consists of a capital and small letter plus a code number. A vector group is a method of specifying a threephase transformer or transformer bank method of connection and its angular displacement. These phasor groups can be better understand by the following examples.
The transformer vector group is indicated on the name plate of transformer by the manufacturer. Separate singlephase transformers can be used and externally interconnected to yield the same results as a 3phase unit. Rphase hv and rphase lv shorted for all vector group of transformer. Secondary star options of naming transformer secondary a b c b a c c b a a aa a a a 6 2 10 17. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Vector group test of power transformer electrical4u vector group test of transformer. Subscribe our electrical engineering related channel electrical academy to get the. Transformer vector group depends upon removing harmonics. Armstrong okai ababio electrical engineer electricity company of ghana c b a primary star equi. Hence every electrical power transformer must undergo through vector group test of. But after the winding connection is made it is necessary.
The power transformer used to transfer the high voltage supply from one place to another. The vector group denotes the way in which the windings are connected and the phase position of their respective voltage vectors. 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. 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. Here yy 0 will mean its both the windings are starconnected and phase displacement between primary and secondary emfs is zero degree.
Sharing abstracts,notes on various electrical engineering topics. 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. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. Dy connection y winding nullifies 3rd harmonics, preventing it to be reflected on delta side. Vector group of transformer electrical engineering portal.
In electrical engineering, a vector group is the international electrotechnical commission iec. 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. The vector group of transformer is an essential property for successful parallel operation of transformers. 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. 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. Transformer vector group connections are made based on the winding polarity. An ordinary transformer consists of two windings called primary winding and secondary winding. How to draw transformer vector group connectionelectrical. In general all transformer vector groups with a wye on the secondary side are acceptable for the use in combination with trio inverters, while in particular the primarydeltasecondarywye arrangements with vector group dyn11, dyn5 or dyn1 are those that most commonly have been specified for our. This webinar brought to you by the relion product family. Transformer vector group what is yd11 etc easy explanation.
Oct 02, 2018 transformer vector group connections are made based on the winding polarity. Applicationnote how to determine transformer vector group. Significance of vector group of transformer your electrical. Understanding transformer vector groups valence electrical. Transformer what is the meaning of dyn11 in a transformer. Points to be consider while selecting of vector group. On the name plate of a three phase transformer, the vector group is written as. Normally, dyn11 vector group using at distribution system. Vector grouping of three phase transformer part 1 youtube. With the wye side as the reference vector at 12 oclock, we can draw the delta side vector at 11 oclock. The determination of vector group of transformers is very important before connecting. May 23, 2012 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. The real time examples for phasor groups of transformer are given here. Liggett group llc tobacco and new valley llc real estate, including douglas elliman.
Every transformer contains its own vector group as shown below figure. Mar, 2018 this video contains vector grouping of three phase transformer for starstar and deltadelta connections. First, connect the test power supply to high voltage winding. Vector group test of transformerthe vector group of transformer is. Training on vector groups of transformer presented by. Howard lorber has served as the companys president and chief executive officer since 1994. The three phase transformer is connected in various ways. But the transformer in which a part of windings is common to both primary and secondary is called auto transformer. Windings can be connected as delta, star, or interconnectedstar zigzag. Transformer, voltage ratio, vector group, impedance, shortwhat is vector group. Transformer vector groups can be a difficult concept to understand. In other words, the vector group gives information about the connection of the tertiary winding.
Vector group is punched on the name plate based on the user requirement by the manufacture. If it is the electromechanical type of relay, you need to do a stability test by changing the ct connections till you arrive at the correct polarity. Vector group of 3 winding transformer cr4 discussion thread. Vector group test of transformerthe vector group of transformer is an essential property for successful parallel operation of transformers.
What is the meaning of transformer vector group yna0d1 answers. Three phase transformer vector grouping significance. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. A transformer threephase vector diagram is required for determining the fault calculation of an electrical power system. Iec has devised the standard code for determination of transformer vector group. An unbalanced group of two or more forces is a group whose vector sum is not zero. Autotransformer vector group cr4 discussion thread. Vector group is an essential characteristics of 3 phase transformer. Aim of vector group test is at site is to check if their is any damage in the windings during transportation and erection. Winding polarity is also important, since reversing the connections across a set of windings affects the phaseshift. Vector group test of transformer is done for detecting the vector group. Vector group test of power transformer electrical study. Practically, almost every electrical power system deals with three phase power.
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. Depends on if you are using a numerical relay if yes than most relays have an option about the vector group of the transformer. Three phase transformers electrical engineering department. It also determines the high voltage and low voltage windings arrangement of three phase transformers. Mar 23, 2019 a transformer threephase vector diagram is required for determining the fault calculation of an electrical power system. 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. Transformer connections from the same group can be. Department of electrical and electronics engineering. The three phase transformer windings can be connected several ways.
This cannot be avoided by selecting a tansformer with a particular vector group. It is likely that the voltage in the tertiary winding is lv, hence d11 not d11. As clearly shown above, there are six vector group options available for star star transformer configuration. 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. What is the meaning of transformer vector group yna0d1. Vector group test of power transformer electrical mastar. The vector group provides a simple way of indicating how the internal connections of a transformer are arranged. Continued from first part understanding vector group of transformer part 1 points to be consider while selecting of vector group vector groups are the iec method of categorizing the primary and secondary winding configurations of 3phase transformers.
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