why star connection used on high voltage side for power transformers?

Question

Normally Power transformer have wye connection on high voltage side i.e 132 kv / 220 kv etc.. What are the advantages over delta connection

Answer 1

I think in special step down cases you may prefer to connect the high voltage side (temporarily) in delta so that you can turn on 3 phase service to the low voltage side with just 2 phase active on the high voltage side.

In normal cases a high voltage side wye connection gives a neutral center point for you to ground to isolate the unbalanced 3-phase load from the low voltage side to improve the margin of stability on your high voltage side. The wye connection, if properly wound, also can better separate the high voltage points in space to let the high voltage side go higher in voltage with the same insulation cost.

Answer 2

famous guy or woman/delta and delta/famous guy or woman connections the two supply a 30 degree section shift. The voltages are the comparable (assuming those are all section-section voltages). so as that leaves despite if or no longer the linked circuits have a independent and wherein direction potential is permitted to circulate. A circuit with a independent (4-twine) could desire to be offered by way of the two a wye winding or a delta winding with an further grounding transformer. a three-twine circuit may well be offered by way of the two a delta or a wye connection. So this substitution will artwork for potential circulate from 11 to 33 kV. For potential circulate from 33 kV to 11 kV this substitution will artwork provided that the 11 kV circuit is 3-twine (no independent) or a grounding economic employer is further despite if that's 4-twine.

Answer 3

1. The delta-star connection is in common for both step-up and step-down purposes. When used as a step-up transformer, the hv winding is Y-connected, when used for step-down purposes, the lv winding is usually Y-connected in order to provide a grounded neutral for secondary transmission or for primary distribution.

2. Delta-connected hv windings, however, are seldom used for transmission voltages of 138kV and above. The delta Y connection almost completely suppresses the triple harmonics with the neutral solidly grounded. Triple harmonics which can appear on power systems are the third and its odd multiples. Y-connected windings on the higher voltages are usually provided with graded insulation, the neutral-end turns of which may have very little insulation if the neutral is solidly grounded.

3. Star-star connected transformers are used infrequently on hv transmission systems. When used with both neutrals grounded, if single phase or three phase shell type, they must be used with Y-connected generators, and a solid neutral connection must be provided between the generator/s and the lv transformer neutral in order to minimize triple harmonic troubles.

4. Delta-delta connected transformers are used mainly on the lower transmission voltages. This is due to the fact that the complete winding must be insulated for full line-to-line voltage: for voltages above 73kV the cost increase is appreciable over Y-connected transformers with graded insulation. The delta-delta connected transformers have one advantage in that the bank can be operated open delta at 86.6% of the capacity of the two remaining transformers.

Answer 4

HV - is generally start connected and LV-is usually Delta connected (except:Distribution transformer )

Star: For high volages amount of insulation required will be high but star can reduce amount of insulation. .
Delta : high current has more 3rd harmonics which can be reduced by Delta connection

Answer 5

Oh..hell. Might as well try. Might be right.
Star (or the proper term, torx bits) are used to lessen the chance of slipping off the fastener and touching a + (or -)terminal causing shock and possibly death (?).

Answer 6

Why are all the answers so short these days?