What is the significance of the 'A-N' voltage on a delta-wye transformer connection, and how can it be used for fault diagnosis?

In a delta-wye transformer connection, the 'A-N' voltage refers to the voltage between phase A and the neutral point (N) on the wye-connected side. In a balanced three-phase system, this voltage is equal to the phase voltage of the wye side. The significance of the A-N voltage lies in its ability to indicate the health and balance of the system, and it is particularly useful for fault diagnosis. Under normal, balanced conditions, the three A-N, B-N, and ....