Significance of vector group of transformer on the nameplate of threephase transformer vector group is printed as yy 0, dd 1 etc. Dy connection y winding nullifies 3rd harmonics, preventing it to be reflected on delta side. The vector group provides a simple way of indicating how the internal connections of a transformer are arranged. Vector group test of power transformer electrical mastar. The type tests of the transformer confirm the main and basic design criteria of a production lot. Description of vector group testing of vector group bangla tutorial for power point slide go to eee practical knowledge. Here yy 0 will mean its both the windings are starconnected and phase displacement between primary and secondary emfs is zero. Vector group of 3phase transformer electrical concepts. In order to understand the presented testing methods some basic. It allows utilities and industrials to maximize the return on transformer assets. Transformer vector group free download as powerpoint presentation.
Th e transformer is one of the most important items of hardware. Dyn11 transformer vector group pdf read 6 answers by scientists with 1 recommendation from their colleagues to the question asked by parth panchal on feb 11, the vector group designation. But after the winding connection is made it is necessary to check if the desired vector group has been achieved. May 15, 2018 vector group matching sgf1 matching is done via interposing cts, but nowadays ieds have a provision of vector group matching, the vector group of the power transformer is numerically matched on. The vector group designation indicates the windings configurations and the difference in phase angle between them. I have faceting problem in testing of transformer vector group dy11y11y11y11,380vx433000v for solar plant i have ask to client for factory test report but he is not providing me. Apply the formula or plot the values in the graph to get the vector group. Type tests are done mainly in a prototype unit not in all manufactured units in a lot. Transformer testing test report linkedin slideshare.
There are several internal connections of threephase transformer are available on the market. The primary windings are connected in one of several. The connection of all the windings in a threephase transformer is indicated by a vector group symbol. 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. Separate singlephase transformers can be used and externally interconnected to yield the same results as a 3phase unit. Vector group test of power transformer electrical study. How do i draw vector group of transformer from winding connection. Differential protection scheme basic and 5mva transformer.
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. The typical result for the vector group test of a ynd1 transformer is shown in fig. This test allows the engineer and relay technicians to validate all the cts and pts secondaries, transformer winding con. In addition some other tests are also carried out by the consumer at site before commissioning and also periodically. 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. For example, a wye hv winding and delta lv winding with a. It consists of a capital and small letter plus a code number. Transformer vector group connections are made based on the winding polarity.
A free powerpoint ppt presentation displayed as a flash slide show on id. 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. Apply 3 phase supply voltage 415 v ac across the primary termination of the transformer. The phase sequence or the order in which the phases reach their. Proper vector grouping in a transformer is an essential criteria for parallel operation of transformers. Electrical technology and industrial practice 6,8 views 15. In other words the vector group of a transformer cannot aid in eliminating the harmonic content in its inrush current. Vector group test of power transformer electrical4u. Transformer vector group determinationelectrical engineering electrical technology duration.
Routine tests and type tests of transformers electrical4u. Feb 08, 2015 mainly two types of transformer are done by manufacturer before dispatching the transformer mainly 1 type test of transformer and 2 routine test. Edvard jun 03, but i want to know about the test methode and voltage relation of different type vector. Transformer vector group effect on substation gpr marmite electrical 6 feb 09. From your question above, i presume that ur understanding of the transformer is not complete. These three voltages have been drawn relative to a common voltage reference or neutral point. In intcv205 transformer vector group applications english pdf course description uk abb university uk training schedule english pdf information transformer service brochure english pdf brochure trafoasset management brochure english pdf brochure power products services retrofit, modernization and service. The story of transformer stability the transformer stability test used to conform the ct connections for differential and ref protection. 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 winding. May 03, 2016 this way customer end power is not affected by the overall vector group of the power system. Abstract of national electrical code for transformers protection. 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. Commissioning a test for a differential protection scheme for.
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. These settings may be revaluated during the commissioning, according to actual and measured values. Best electrical lecture notes pdf download class tutorials. The earthing transformer therefore provides a low reactance to 11 kv earth faults. It also determines the high voltage and low voltage windings arrangement of three phase transformers.
Mainly two types of transformer are done by manufacturer before dispatching the transformer mainly 1 type test of transformer and 2 routine test. The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration of transformer windings connection. Effective maintenance test techniques and diagnostic. There is no technical difference between the one vector groups i. The determination of vector group of transformers is very important before connecting two or more transformers in parallel. 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. Protection selectivity is partly considered in this report, and could be also revaluated.
A transformer has no moving parts and is a completely. It considers the practical understanding of a variety of tests and prescribes how to plan and implement them carefully. Vector group is punched on the name plate based on the user requirement by the manufacture. It can be designed to step up or step down voltages and works on the magnetic induction principle. If we want to connect two transformer in parallel then their phase shift should be same, otherwise there will be a. Please note that u cannot have two different vector group on a single transformer,i. Mainly, the type of transformer connections are divided in 4 below groups.
The vector group indicates the phase difference between the primary and secondary sides, introduced due to that particular configuration. The transformer vector group is indicated on the name plate of transformer by the manufacturer. The recalculation factor is pending transformer vector configuration and when applicable also the actual ttr test setup including eventual shorts to create a virtual neutral terminal. Abstract of over current protection of transformer nec 450. Why are ynd1ynd11 the most common vector groups for power. Autotransformer vector group cr4 discussion thread.
An ampereturns balance is also achieved for the lvac out of balance or earth fault conditions such that the earthing transformer with this vector grouping presents a low reactance. From a vector group one can determine the phaseshift between primary and secondary. Dec 12, 2017 vector group test, check the voltage phase shift of two or more transformer. Abb provides services throughout the transformer life cycle, from commissioning to recycling, for all brands and kinds of transformers. Measure the voltage at the both primary and secondary termination at all the phases.
Single phase transformer and applications of single phase transformer. Vector grouping of three phase transformer part 2 youtube. Earthing transformer an overview sciencedirect topics. Pdf easy method for testing transformer differential relays. Department of electrical and electronics engineering. Importance and elimination of third harmonics application and selection of vector group of transformer. Vector group test is done in order to know the phase displacement between the high voltage and low voltage winding. In a 3 phas e transformer, it is essential to carry out a vector group test of transformer. Names of parameters in this calculation may differ from those in. There are various test required on transformer to conform performance of transformer. Apply to test engineer, program coordinator, mechanic and more.
Schneider electric design engineer interview questions. Index terms transformer, throughfault, substation, commission and testing. This technical report refers to the electrical protections of all 2kv switchgear. The method can be easily implemented in a protection relay test set 14, in order to facilitate the task for the test engineer. Vector group of transformer electrical engineering portal. This way customer end power is not affected by the overall vector group of the power system. Transformer vector group the vector group test is importent test in the transformer testing. The vector group of transformer is an essential property for successful parallel operation of transformers. Understand significance of vector groups interpret the vector group notations used on transformer name plates content. You are requested please help me, i am electrical engineer and working for solar power plant first time. A transformer is an electrical apparatus designed to convert alternating current from one voltage to another.
A bank of three singlephase transformers cost about 1. How to draw vector group of transformer from winding. Aim of vector group test is at site is to check if their is any damage in the windings during transportation and erection. This symbol indicates the winding connections and their relative phase displacement by means of a numerical index e. According to iec764, the value of vector group can be 0,1,2,4,5,6,7,8,10,11. Then they ask me to draw sld of the power plant where i did my training. Vector groups identify the winding connections and polarities of the primary and secondary. 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.
For each vector group need diffrent type of voltage combination to conform the vector group refer drawings. This gl o macs training seminar covers all aspects of testing in electrical systems, performed during construction or maintenance. Vector group of 3 winding transformer cr4 discussion thread. Measure the voltages in various combination on both side of the transformer hv lv. Pdf transformer vector group test conditions k pandian. Why are the u1 of hv and u2 of the lv side of a transformer in the dyn11 vector group test. 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. Singlephase transformers may be specified for hydraulic stations because of transport. Armstrong okai ababio electrical engineer electricity company of ghana. What is the test procedure of vector group of a transformer.
Vector group test, check the voltage phase shift of two or more transformer. Through vector group of a transformer we can know that the winding configuration of a transformer. Vector group test of transformer testing of transformer. Relay settings calculations electrical engineering. The power transformer used to transfer the high voltage supply from one place to another. Easy method for testing transformer differential relays. The phase sequence or the order in which the phases reach their maximum.
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