They all have delta primaries and star secondaries, possibly earthed. The number is the angle of the secondary voltage's lag behind the primary's, expressed as an hour on a clock-face.
11 --> Secondary leads primary by 30 degrees
1 --> Secondary lags primary by 30 degrees
5 --> Secondary lags primary by 150 degrees, making the red secondary voltage lag the yellow primary by 30 degrees (using UK Red/Yellow/Blue phases)
Dyn11 and Dyn1 are much more common than DYn5
Yes, you can replace a DY11 transformer with a DYN11 transformer, but it is important to consider the differences in their winding configurations and phase shifts. The DY11 transformer has a wye (star) connection on the primary side and a delta connection on the secondary side, while the DYN11 transformer has a delta connection on the primary side and a wye connection on the secondary. This change in configuration may affect voltage levels and phase relationships in your system, so it's essential to ensure compatibility with existing equipment and load requirements. Always consult with an electrical engineer before making such a replacement.
This vector group test is done to confirm whether the vector group provided in the name plate is correct or not and also to confirm that the winding has not been damaged during transport, installation and erection. Taking a particular example, for Dyn11 transformer we have to apply 3~ 400v to the primary, with primary 'U' & secondary 'u' shorted.... then check the voltage across different terminals such as V-v, V-w, W-w, W-v for Dyn11 configuration (V-v = V-w = W-w)less than W-v.... you can compare the results after drawing the vector diagram for the same...... the purpose of shorting the primary U & secondary u is to nullify the phase shift, to obtain a reference vector...
To convert a transformer connection from Zy5 (Zy5 is a delta connection on the high-voltage side and a star connection on the low-voltage side) to Dyn11 (which indicates a delta connection on the high-voltage side, a star connection on the low-voltage side, and a phase displacement of 30 degrees), you need to ensure that the phase shift is appropriately accounted for. This involves rearranging the connections of the transformer windings and possibly adjusting the phase sequence to achieve the required 30-degree phase displacement between the high-voltage and low-voltage sides. Proper testing and verification must be conducted to ensure that the new configuration operates correctly and safely.
The phase shift is caused by inductance in the transformer. Any inductance from magnetic flux that fails to link both windings is called leakage flux, and the resulting inductance is called leakage inductance.
connect the neutral point of the star (secondary) to u phase of primary, and now apply voltage to primary and measure the voltage between V&R, W&B, V&Y and V&B. when you measure voltage b/w 1. V&R the voltage must be maximum, 2. W&B Should be minimum and 3. voltage between V&Y and V&B should be same U.V&W are primary (Delta) R,Y&B are secondary (Star)
The key difference between Dyn11 and Dyn1 refers to their vector groups. Dyn11 has a neutral terminal connected to the star point of one of the windings, while Dyn1 does not have this connection. This means that in Dyn11, the neutral terminal is available for grounding or other purposes, which may affect system protection and grounding schemes.
The vector grouping of a DYN1 transformer is determined by the relative phase shift between the primary and secondary windings. It is designated based on the clock-hour positions of the HV and LV terminals when the high voltage winding is at 12 o'clock and the low voltage winding is positioned accordingly. The vector group is typically denoted as Dyn1, Dyn5, Dyn11, etc., indicating different phase relationships.
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
Yes, you can replace a DY11 transformer with a DYN11 transformer, but it is important to consider the differences in their winding configurations and phase shifts. The DY11 transformer has a wye (star) connection on the primary side and a delta connection on the secondary side, while the DYN11 transformer has a delta connection on the primary side and a wye connection on the secondary. This change in configuration may affect voltage levels and phase relationships in your system, so it's essential to ensure compatibility with existing equipment and load requirements. Always consult with an electrical engineer before making such a replacement.
This vector group test is done to confirm whether the vector group provided in the name plate is correct or not and also to confirm that the winding has not been damaged during transport, installation and erection. Taking a particular example, for Dyn11 transformer we have to apply 3~ 400v to the primary, with primary 'U' & secondary 'u' shorted.... then check the voltage across different terminals such as V-v, V-w, W-w, W-v for Dyn11 configuration (V-v = V-w = W-w)less than W-v.... you can compare the results after drawing the vector diagram for the same...... the purpose of shorting the primary U & secondary u is to nullify the phase shift, to obtain a reference vector...
It's a description of the some of the electrical properties of the transformer. This is a Delta connected highside (the D), wye connected lowside (Y) that is grounded (N) and there is a 330 degree phase shift between the highside and the lowside (the low voltage is leading the high voltage by 30 degrees).
To convert a transformer connection from Zy5 (Zy5 is a delta connection on the high-voltage side and a star connection on the low-voltage side) to Dyn11 (which indicates a delta connection on the high-voltage side, a star connection on the low-voltage side, and a phase displacement of 30 degrees), you need to ensure that the phase shift is appropriately accounted for. This involves rearranging the connections of the transformer windings and possibly adjusting the phase sequence to achieve the required 30-degree phase displacement between the high-voltage and low-voltage sides. Proper testing and verification must be conducted to ensure that the new configuration operates correctly and safely.
The phase shift is caused by inductance in the transformer. Any inductance from magnetic flux that fails to link both windings is called leakage flux, and the resulting inductance is called leakage inductance.
iT IS ISMILAR TO THE GROUND RESITOR CALCULATION FOR TRANSFOMER THE TYPICAL EXAMPLE WAS ANSWERED EARLIER FOR TRANSFORMER DT.19-06-2009 Neutral of transformer can be grounded solidly earthed OR with Neutral Grounded with Resistance. Typical shunt calculations fro 5 MAV 11/6.6 kv transformer neutral are as :_ Transformer rating = 5 MVA Voltage ratio = 11/6.6 KV Vector Group = Dyn11 (6.6 KV ground through Resistor) During Earth fault voltage between Neutral & Earth = 6.6/√3 = 3.81 KV Earth Fault current will be limited to = 5 x 10³ /(√3 x 6.6) = 437.38Amp. N.G.R. value in ohm = V / I = (3.81 x 10³) / 437.38 = 8.71 Ohm Value of N.G.R. is 437.38 Amp, 8.71 Ohm., 10 Sec NGR are inserted On Higher voltage to restrict earth fault current BY SRI
connect the neutral point of the star (secondary) to u phase of primary, and now apply voltage to primary and measure the voltage between V&R, W&B, V&Y and V&B. when you measure voltage b/w 1. V&R the voltage must be maximum, 2. W&B Should be minimum and 3. voltage between V&Y and V&B should be same U.V&W are primary (Delta) R,Y&B are secondary (Star)
No
To measure the zero sequence impedance of a 20 MVA DYn11 transformer, you can perform a three-phase short-circuit test on the secondary side while ensuring that the primary side is isolated. Connect the secondary windings in a star configuration to facilitate zero sequence measurement. Apply a three-phase voltage to the primary side and measure the resulting current and voltage on the secondary side. Calculate the zero sequence impedance using the formula ( Z_0 = \frac{V_{sec}}{I_{sec}} ), where ( V_{sec} ) is the measured voltage and ( I_{sec} ) is the measured current during the test.