Answer Posted / raj_singh_0376

Procedure of vector group test of transformer


Let’s have a YNd11 transformer.

1) Connect neutral point of star connected winding with earth.

2) Join 1U of HV and 2W of LV together.

3) Apply 415V, three phase supply to HV terminals.

4) Measure voltages between terminals 2U – 1N, 2V – 1N, 2W – 1N, that means voltages between each LV terminal and HV neutral.

5) Also measure voltages between terminals 2V – 1V, 2W – 1W and 2V – 1W.

For YNd11 transformer, we will find,
2U – 1N > 2V – 1N > 2W – 1N
2V – 1W > 2V – 1V or 2W – 1W

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