Delta- Star Connection Overview

In this variety of association, the first connected in delta fashion whereas the secondary current is connected in star.

Delta-Star Connection

Key points

As primary in delta connected:

  • As Secondary in Star connected
  • Line voltage on primary facet = part voltage on Primary facet.
  • Secondary part Voltage = K X Primary part Voltage.
  • Now Transformation Ration (K) = Secondary part Voltage / Primary part Voltage
  • Line voltage on Secondary facet = √3 X part voltage on the Secondary facet. So,
  • Line voltage on Secondary facet = √3 X K X Primary part Voltage.
  • Line voltage on Secondary facet = √3 X K X Primary Line Voltage.
  • There is s +30 Degree or -30 Degree part Shift between Secondary part Voltage to Primary part Voltage


As for instance, at the start of associate HT cable. during this case, a neutral purpose is stable and can not float just in case of unbalanced loading. there’s no distortion of flux as a result of the existence of a Δ -connection permits a path for the third-harmonic elements.

The line voltage quantitative relation is √3 times of electrical device turn-ratio and also the secondary voltage leads the first one by 30°. In recent years, this arrangement has become very hip for the distribution system because it provides 3- Ø, 4-wire system.

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