Vector group test of power transformer electrical study. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. There is no technical difference between the one vector groups i. Transformer vector group free download as word doc. Rphase hv and rphase lv shorted for all vector group of transformer. Based on the windings connection, the vector group of the transformer. Export graph images to pdf, jpeg, eps, and more origin. Vector group of 3phase transformer electrical concepts. Understand significance of vector groups interpret the vector group notations used on transformer name plates content. Transformer vector group connections are made based on the winding polarity. The vector diagrams are given in the name plate details of the transformer. What is meant by vector group for transformers and why is. Please note that u cannot have two different vector group on a single transformer,i. A vector group is a method of specifying a threephase transformer or transformer bank method of connection and its angular displacement.
Measure the voltages in various combination on both side of the transformer hv lv. All transformers are subjected to various tests at the manufacturer. From your question above, i presume that ur understanding of the transformer is not complete. 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. Yes, the name plate vector group of a transformer is only valid for a standard phase rotation abc. Note that when determining the angle between h1 and x1, the rotation must be clockwise. What is the meaning of transformer vector group yna0d1. A user friendly simulation for transformer vector group. These phasor groups can be better understand by the following examples. 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. How to draw transformer vector group connectionelectrical.
For example, a wye hv winding and delta lv winding with a. In addition to the voltage ratios and kva ratings, one of the most important specifications is the transformer vector group. Vector group is an essential characteristics of 3 phase transformer. A transformer vector group is required to be known from the angle of parallel operation of two similar transformers. Transformer connections from the same group can be. 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. Transformer vector groups can be a difficult concept to understand.
Transformer vector group the vector group test is importent test in the transformer testing. The real time examples for phasor groups of transformer are given here. Vector group of transformers free download as powerpoint presentation. The action of a transformer is a particular case of the principle of mutual inductance, and a transformer consists essentially of two windings, the primary and secondary on a common magnetic core. Based on the windings connection, the vector group of the transformer is determined. Transformer vector group what is yd11 etc easy explanation.
The determination of vector group of transformers is very important before connecting two or more transformers in parallel. Vector group test of transformerthe vector group of transformer is an essential property for successful parallel operation of transformers. Vector group test of transformer the vector group of transformer is an essential property for successful parallel operation of transformers. Applicationnote how to determine transformer vector group. Vector group is punched on the name plate based on the user requirement by the manufacture. Easily convert pdf to jpg with this free online converter.
One procedure of vector group testing of transformer is explained as. A three phase transformer is one of the vital apparatus in the power systems. The three phase transformer windings can be connected several ways. This video outlines the vector groups that you will come across on a typical transformer and explains the principles of phase shift, and is a. Three phase transformer vector grouping significance. 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. Every transformer contains its own vector group as shown below figure.
On the name plate of a three phase transformer, the vector group. Vector group test of power transformer electrical mastar. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. In other words, the vector group gives information about the connection of the tertiary winding. You can only upload files of type 3gp, 3gpp, mp4, mov, avi, mpg, mpeg or rm. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Vector group test of power transformer electrical4u. The transformer vector group is indicated on the name plate of transformer by the manufacturer. Transformer vector group free download as powerpoint presentation. But after the winding connection is made it is necessary to check if the desired vector group has been achieved. 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 applications. The vector group of transformer is an essential property for successful parallel operation of transformers.
Pdf to jpg online converter convert pdfs to jpg images for free. Contents hide 1 basic idea about transformer vector group 1. 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. Autotransformer vector group cr4 discussion thread. 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. Will it make any difference as far as the vector group is concerned if instead of phase a and c, phase b and c were swapped on both ends of the transformer.
Transformer nameplates carry a vector group reference such at yy0, yd1, dyn11 etc. 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. With the wye side as the reference vector at 12 oclock, we can draw the delta side vector at 11 oclock. The vector group designation indicates the windings configurations and the difference in phase angle between them. Vector group test of transformer is done for detecting the vector group. The clock method is used to produce the numerical index of the vector group. The transformer vector group show the phase difference between the primary and secondary sides of the transformer. Transformers connected in parallel must have the same vector group.
The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. 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. Transformer what is the meaning of dyn11 in a transformer. Importance and elimination of third harmonics application and selection of vector group of transformer. Transformer vector group transformer voltage scribd. It means lv winding,which is star connected written in small letters means lv. Aim of vector group test is at site is to check if their is any damage in the windings during transportation and erection. Vector groups pdf transformer electric power scribd. Vector group of 3 winding transformer cr4 discussion thread. Significance of vector group of transformer on the nameplate of threephase transformer vector group is printed as yy 0, dd 1 etc. In electrical engineering, a vector group is the international electrotechnical commission iec.
It also determines the high voltage and low voltage windings arrangement of three phase transformers. The vector group transformer test is important for connecting two power transformer in parallel. Pdf transformer vector group test conditions k pandian. It is likely that the voltage in the tertiary winding is lv, hence d11 not d11. For the love of physics walter lewin may 16, 2011 duration. These tests are done when the tap of transformer is nominal. Based from this, we can say that this transformer connection belongs to the vector group ynd11. We have transformer of dyn11, if we change the phase sequence can transformer vector group change. Two of them are in range of normal skewness value i. The vector group of transformer is the phase difference between the primary and the secondary sides.