0
What does Dd0, Dyn11, YNd5 etc. mean?
First symbol/symbols, capital letters: HV winding connection.
Second symbol/symbols, small letters: LV winding connection.
Third symbol, number: Phase displacement expressed as the clock hour number.
Winding connection designations
High Voltage Always capital letters
Delta - D
Star - S
Interconnected star - Z
Neutral brought out - N
Low voltage Always small letters
Delta - d
Star - s
Interconnected star - z
Neutral brought out - n
Phase displacement
Phase rotation is always anti-clockwise. (international adopted convention)
Use the hour indicator as the indicating phase displacement angle. Because there are 12 hours on a clock, and a circle consists out of 360°, each hour represents 30°.
Thus 1 = 30°, 2 = 60°, 3 = 90°, 6 = 180° and 12 = 0° or 360°.
The minute hand is set on 12 o'clock and replaces the line to neutral voltage (sometimes imaginary) of the HV winding. This position is always the reference point.
Because rotation is anti-clockwise, 1 = 30° lagging (LV lags HV with 30°)and 11 = 330° lagging or 30° leading (LV leads HV with 30°)
To summarise:
Dd0
Delta connected HV winding, delta connected LV winding, no phase shift between HV and LV.
Dyn11
Delta connected HV winding, star connected LV winding with neutral brought out, LV is leading HV with 30°
YNd5
Star connected HV winding with neutral brought out, delta connected LV winding, LV lags HV with 150°
Add your answer:
Earn +20 pts
Give you a phasor diagram of dyn 5 and dyn 11?
could you give a schematic diagram of vector dyn 1
Why differential relay is not used for 11kv transformers?
It depends what you mean by an '11-kV transformer'; do you mean a primary transformer (33/11-kV transformer) or a distribution transformer (11-kV/400-230-V transformer). Differential protection IS offered on primary transformers.
Is line voltage or phase voltage mentioned on transformer nameplate?
It depends how they are connected. If they are connected between line conductors then they are measuring line voltages. If they are connected across phases then they are measuring phase voltages.
What is the maximum capacity of 11kv transformer?
It depends on the design of the transformer but 1 MVA is a common size for an 11 kV / 415 v three-phase transformer.
Its possible to convert 11 kv to 5v by potential transformer?
If you have to ask this question, you shouldn't be dealing with 11,000V
What is the meaning of DY 11 on a transformer nameplate?
there is no specification of Dy11.. it will be Dyn11.. it is the vector group of the transformer. capital d means primary winding is delta secondary winding is star(y) and the secondary current lags voltage by 30degree this angle when shown in clock will be looking like 11 o clock
Give you a phasor diagram of dyn 5 and dyn 11?
could you give a schematic diagram of vector dyn 1
Why differential relay is not used for 11kv transformers?
It depends what you mean by an '11-kV transformer'; do you mean a primary transformer (33/11-kV transformer) or a distribution transformer (11-kV/400-230-V transformer). Differential protection IS offered on primary transformers.
Is line voltage or phase voltage mentioned on transformer nameplate?
It depends how they are connected. If they are connected between line conductors then they are measuring line voltages. If they are connected across phases then they are measuring phase voltages.
What is the maximum capacity of 11kv transformer?
It depends on the design of the transformer but 1 MVA is a common size for an 11 kV / 415 v three-phase transformer.
What is unit transformer?
UniT transformer are step up transformer which is connected to generating house & step up voltage from 11/15kV votlage to 220/400kV voltage level as requirement or line design parameter. It is just like transformer but connected to unit of the generating house that's why we called it unit transformers.
How many dewa cable from transformer to mdb?
11 CABLES 630 mm2 single core
Are taxes the sole source of government income?
No. For example, the Federal Reserve can make a profit that the U.S. Treasury keeps (http://www.washingtonpost.com/wp-dyn/content/article/2010/01/11/AR2010011103892.html).
When was The Meaning of Liff created?
The Meaning of Liff was created on 1983-11-11.
Its possible to convert 11 kv to 5v by potential transformer?
If you have to ask this question, you shouldn't be dealing with 11,000V
How do you calculate rating of 11 kv transformer?
The KVA rating of a transformer is based on how much heat the transformer can dissipate. The BIL rating is based on how well the windings are insulated. There are other "ratings" as well. Rough calculations can be done, but tests are generally performed to prove the calculations (transformer designers will design on the conservative side to insure the transformer meets specification). These type of calculations are best done by a computer. You will struggle to determine the hot spot max temperature rise in a transformer by hand.
What is the name for an 11-sided polygon?
An 11-sided polygon is called a hendecagon or an endecagon from the Greek endeka- meaning 11, and -gon meaning angle.
