In electrical engineering, a vector group is the international electrotechnical commission iec. Separate singlephase transformers can be used and externally interconnected to yield the same results as a 3phase unit. The transformer vector group is indicated on the name plate of transformer by the manufacturer. Vector group test of power transformer electrical study app. Why are ynd1ynd11 the most common vector groups for power.
The primary coil, which receives energy from the ac source. The primary windings are connected in one of several ways. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. Every transformer contains its own vector group as shown below figure. Dy connection y winding nullifies 3rd harmonics, preventing it to be reflected on delta side. 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. This was done in order to create a notation for threephase transformer winding configuration. If we want to connect two transformer in parallel then their phase shift should be same, otherwise there will be a. Vector group of transformers transformer electric power. The current transformer is used for measuring the high voltage current because of the difficulty of inadequate insulation in the meter itself. How to draw transformer vector group connectionelectrical. These phasor groups can be better understand by the following examples.
The transformer the principle parts of a transformer and their functions are. How to draw vector group of transformer from winding. According to iec764, the value of vector group can be 0,1,2,4,5,6,7,8,10,11. The primary windings are connected in one of several. It transforms the high voltage current into the low voltage current due to which the heavy current flows through the transmission lines is safely monitored by the ammeter. A transformer has no moving parts and is a completely. Windings can be connected as delta, star, or interconnectedstar zigzag. Winding polarity is also important, since reversing the connections across a set of windings affects the phaseshift between primary and secondary.
Understanding transformer vector groups valence electrical. Vector group is an essential characteristics of 3 phase transformer. Jun 24, 2015 create a book download as pdf printable version. Transformer vector group effect on substation gpr electric. The authors describe a singlephase transformer design suitable for classroom use. The vector group of transformer is an essential property for successful parallel operation of transformers. A current transformer is a device that is used for the transformation of current from a higher value into a proportionate current to a lower value.
Points to be consider while selecting of vector group. The following examples are for two winding three phase transformers. A powerful application, combining two utilities in one product pdf conversion and pdf creation. A transformer is a device used to change the voltage levels of electricity to facilitate the. Vector groups are the iec method of categorizing the primary and secondary winding configurations of 3phase transformers.
Group 4 has phase displacement of 30 degree lead, i. 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 core of the current transformer is built up with lamination of silicon steel. In a current transformer, if we double the turns in the primary, what happens to the secondary current. Importance and elimination of third harmonics application and selection of vector group of transformer. So it is utmost necessary to know how the inter connections to be made to. Jun 18, 2012 vector group of transformer introduction. Training on vector groups of transformer presented by. Estimation of voltage ratio, vector relationship, impedance. The core, which makes a path for the magnetic flux. Vector group of 3 winding transformer cr4 discussion thread. G l issues to consider when substituting large power. This cannot be avoided by selecting a tansformer with a particular vector group.
This means that a 3phase transformer can have its primary and secondary windings connected the same deltadelta or starstar, or differently. The three phase transformer is connected in various ways. Vector group in transformer pdf economical home lighting. Dennis merchant video on vector diagrams for transformer connections. 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. The vital large transformers in a power plant are the unit stepupmain generator transformer ut, the auxiliary transformer uat and the station servicereserve transformer sst. In a delta connected dd group of transformers, the line voltage, vl is equal to the supply voltage, vl vs. Howard lorber has served as the companys president and chief executive officer since 1994.
Vector group test of transformer testing of transformer. From a vector group one can determine the phaseshift between primary and secondary. Here yy 0 will mean its both the windings are starconnected and phase displacement between primary and secondary emfs is zero. Liggett group llc tobacco and new valley llc real estate, including douglas elliman. Transformer vector group what is yd11 etc easy explanation. 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. Here yy 0 will mean its both the windings are starconnected and phase displacement between primary and secondary emfs is zero degree. Find electrical transformer stock images in hd and millions of other royaltyfree stock photos, illustrations and vectors in the shutterstock collection. Why do we need to define a vector group in a transformer. What is meant by vector group for transformers and why is.
The vector group designation indicates the windings configurations and the difference in phase angle between them. The real time examples for phasor groups of transformer are given here. The power transformer used to transfer the high voltage supply from one place to another. Significance of vector group of transformer on the nameplate of threephase transformer vector group is printed as yy 0, dd 1 etc.
Transformers connected in parallel must have the same vector group. But due to some reason i failed to get job in that field and continued my own field. The secondary coil, which receives energy from the primary winding and delivers it to the load. How do i draw vector group of transformer from winding connection. 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. Polarity refers to the instantaneous direction of the primary current with respect to the secondary current and is determined by the way the transformer leads are brought out of the case. Vector group test of power transformer electrical study.
The determination of vector group of transformers is very important before. Understanding transformer vector groups transformer vector groups can be a difficult concept to understand. The phase sequence or the order in which the phases reach their. The naming convention popularly known as vector group of transformer was established by the international electrotechnical commission iec through iec 600761. 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. The three phase transformer windings can be connected several ways. It can be designed to step up or step down voltages and works on the magnetic induction principle. Transformer vector group free download as powerpoint presentation. Interpret the vector group notations used on transformer name plates content. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. This video goes with 3rd year transformer connections units of. The vector group denotes the way in which the windings of a transformer are connected and the phase position of their respective voltage vectors. It also determines the high voltage and low voltage windings arrangement of three phase transformers.
In a current transformer, if we double the turns in the primary. The harmonics in a transformer are present only in the transformer inrush current predominantly 2 nd harmonic content. Description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. It consists of a capital and small letter plus a code number. On subtractive polarity transformers the h1 primary lead and the x1 secondary lead will be on the same. The clock method is used to produce the numerical index of. Mainly, the type of transformer connections are divided in 4 below groups.
Dec 22, 2017 description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. Pdf transformer vector group test conditions k pandian. The vector diagrams are given in the name plate details of the transformer. The determination of vector group of transformers is very important before connecting two or more transformers in parallel. The current transformer is used in meters for measuring the current up to 100 amperes. Grammarly is a comprehensive writing tool that helps you write clear, flawless text. Vector group of a transformer vector group of a transformers. Adobe acrobat reader is free software that lets you view and print portable document format pdf files. The phase sequence or the order in which the phases reach their maximum. Based on the windings connection, the vector group of the transformer is determined. Liggett group llc founded in 1873, liggett group llc is the fourthlargest cigarette manufacturer in the u. A transformer is an electrical apparatus designed to convert alternating current from one voltage to another.
Significance of vector group of transformer your electrical. The vector group provides a simple way of indicating how the internal connections of a transformer are arranged. If you are using a station auxiliary converter for startup and then when transferring the load to generator auxiliary transformer you must pick the vectors such that the secondarys of each are in phase and the primary of the. Three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the transformer vector group calculation. Threephase transformers can have their windings connected in various ways. Vector groups identify the winding connections and polarities of the primary and secondary. Transformer vector group effect on substation gpr marmite electrical 6 feb 09. Dec 12, 2017 vector group test, check the voltage phase shift of two or more transformer. Understanding vector group of transformer part 1 the primary windings are connected in one of several ways. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Instrument transformer theory and testing steve hudson, pe engineering manager 10737 lexington drive knoxville, tn 37932 phone. A transformer of group 3 can be connected in parallel with that of group 4 by cross connecting any two of the three external connections on hv side, without any other changes. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration. The transformer vector group show the phase difference between the primary and secondary sides of the transformer.
What is the effect of the circulating current in the circuit that has two transformers in parallel. Vector group test of power transformer electrical mastar. 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. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. The scope of this design is limited to the specification for the core and coils of the transformer. This intuitive, versatile, multilingual tool enables you to easily convert any type of pdf into editable formats with the original layout and formatting retained. The threephase transformer noratel separate singlephase transformers with shared limbs in which the magnetic. Vector group test of power transformer electrical4u vector group test of transformer. Vector group test of power transformer electrical4u. Vector group of 3phase transformer electrical concepts. The clock method is used to produce the numerical index of the vector group. 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. Vector group test, check the voltage phase shift of two or more transformer. Transformer differential protection is generally quite simple, but requires the correct application and connection of current transformers and an understanding of the power transformer winding connections, characteristics and operation.
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