For example, a step-up transformer with a delta-connected primary, and star- connected secondary, is not written as ‘dY11’, but ‘Yd11’. The As different combinations of winding connections will result in different phase angles between the voltages on the windings, transformers connected in parallel . classic distribution transformers for electric power supply. Oil and gas . Dy11– 20°. 1 x (Dy5 Dd0). +°. 1 x (Dy5 Dd0). –°. 1 x (Dy11–10° Dy Dy11–10°) .
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May 23, Comments. 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 single-phase transformers can be used and externally interconnected to yield the same results as a 3-phase unit. The primary windings are connected in one of several ways. The two most common configurations are the delta, in which the polarity end of one winding is connected to the non-polarity end of the next, and the star, in which all three non-polarities or polarity ends are connected together.
The secondary windings are connected similarly. This means that a 3-phase transformer can have its primary and secondary windings connected the same delta-delta or star-staror differently delta-star or star-delta. This is called a 30 degree phase shift. When two transformers are connected in parallel, their phase shifts must be identical; if not, a short circuit will occur when the transformers are energized. For selecting Distribution Transformer: Dd0 no phase displacement between HV and LV.
Parmar Jignesh Parmar has completed M. Tech Power System ControlB. He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. In a system of 1 grid incomer connected to Dy11 transformer and a local generator connected to Dy1 transformer is it possible to synchronise the two incomers?
What is meant by vector group for transformers and why is it important?
Thank you so much for whatever you have, the best you are giving to us regarding the subject Transformers. I understood that the generator transformer vector group is delta at generator side and star in yard side. But in your article it is mentioned as reverse order. Parmar, While I appreciate your article on significance and selection of vector group of Transformers, pl. What would be the repercussion if the earthing transformer is not provided?
I have installed and operated no. Secondly, can we opt for YnYno Transformer for such application apart from the above widely used vector group X-mer which will be more economical too.
Is there any constraint in Yy0 configuration? The 21 being normal tap and having 25 taps is not unusual. Probably your supply must be going 1. This is a fantastic tropics. But I want to know about the test methode and voltage relation of different type vector group. Please give the detail procedure of vector group test with the example of.
rtansformer I would like to add another interesting point: The positive effect and other characteristics of transformers of certain vector groups on the mitigation of voltage sags. This can be done by the positive effect of transformers of vector group 1, 5, 7 and 11 e. Dy1, Yd5 etc on asymmetrical faults and especially as regards one-phase-to-ground faults, which are the most frequent faults. Moreover, it can be proved that two-phase, two-phase-to-ground and tarnsformer faults at the one side of such transformers give the same sag magnitude at the other side of the transformer under common assumptions used transofrmer short-circuit analysis.
I have published a journal and a conference paper on that effect. This is a good ready reference regarding vector group and selection of various vector groups.
I would like to ask one thing regarding distribution transformers.
Vector Group of Transformer | Electrical Notes & Articles
transsformer As you know the distribution system normally on HV side connected in parallel and LV side radial. That means the LV of two transformers will never be connected in parallel.
In that case, can we connect the two distribution transformers with different vector group in parallel? Thanks, To clearify my problem of vector group…transformer?
Why DYN11 vector group used in Distribution transformer?
I do not even know how I ended up right here, but I assumed this submit used to be good. I read this article and i realy appreciate your efforts. Thanks for sharing this information. This is very helpful for people……. How to give earth fault protection? What are the only phase displacements in degrees with which it is possible to parallel the secondaries of two transformers? Does tdansformer downstream transformer vektor groups have an effect on fault currents.
This is specifically as distance from the source and voltage levels have effect. Iam impressed by the explicit information about the transformerand i say congrat and keep it up.
But I have spent much time in field of distribution. Can u advise how to check Power theft of consumers by the distribution companies. Sir,we are designing a 50MVA solar power plant in India. We need some clarification while selecting the transformers. First we are stepping up the voltage from V to 22KV,further we are stepping up to KV for transmitting. Here which type Eg. Dy,Yy or Dy we need to select for the above one. The answer will be useful for us to design.
Your electrical notes are very very helpful. And i need a help i searched some more related to transformer but not able to get exact application for dry type transformer, upto what ratings the dry type transformers are used and exact difference between oil immersed transformer and trransformer type transformer. Once again ry11 to u. Can the Transformers with vector group Dyn11 or YNyn0d11 be used?
The UAT unit auxiliary trafo on the generator busduct tap-of is Dyn My question is whether I need to match the u v w by doing interchange of phases in the busduct or I can connect generator u with GSU w and so on. In such case the GSU vector group will change or not.
If yes than the what should be the vector group for UAT? This is such a well written article. How can we get a copy to print out or in dy11 Dear sir can you tell me procedure for finding vector group for unknown vector group of a transformer.
Hi Jignesh What would be the effects on the Zigzag neutral current during normal system operation, if the voltages are severely unbalanced due to load yd11 on the tramsformer system feeders? Assuming Ynd1 Transformer with Zigzag connected on delta side for grounding purposes. Dear Sir, Please describe which type of load is suitable for which vector group of transformer.
We have a DYN5 Transformer which is used as a step down transformer The transformer is a stand alone and is NOT in parallel with any other device.
I have doubt in your drawings for zigzag connection. Thanks Sir; Could you help me for my case. Is it ok at connection, what about distribution and how to nuetral earting. Please reply me Please reply me Thanks again. I would like to synchronise LT V Generator voltage driven by back pressure steam to a LT bus derived out of dyn11 transormer. I invite your posiblility and suggesstions from author and the group please.
Hai everybody is anybody knows about the Yd You stated that in Dy connectiony nullifies the 3rd harmonics.
I request to you, please explain that point. Hai Parmar Sir your informations are very educative, basically Iam from instrumentation area. Can you please guide me how to calculate nominal maximum demand NMD.
Iam sizing trqnsformer for MCC. Sir its very helpfull. What is floating neutral and. So can we suggest to the client for YNd Seeking your please help us in this regard.
Sir, On a converter transformer name plate ,connection is written as Transfoormer It is a 3 phase transformer with 6 secondary windings. Normally Dyn11 vector group using at distribution system. Because Generating Transformer are YNd1 for neutralizing the load angle between 11 and 1. Dyn1, the phase difference will be nullified. In this modern times is it need for sending power both ways in a transfomer. How will this be affected by the vector lag, in an Dyn11?
Will the vectors change from Dyn11 to Yd1 depending of the power direction? I have one straight transsformer not so simple question. Is it possible to build a transformer with the following spec:.