This can be achieved easily by phase shifting the Ac sources using two three-pulse transformers, one of which is Y-connected and the other -connected on the secondary side. On the primary side, both transformers are connected in Y to the same three-pulse source. With this connection, the secondary side phase voltages of the - transformer are shifted in phase by 30,so all the secondary phase voltages of one transformer will be shifted in phase by the same 30 with respect to the corresponding phases in the other. There will also be a difference in the magnitude of the secondary phase voltage.The secondary voltage of the - transformer will be less by a factor of 3 than that of the Y transformer. However, this can be taken care of by having a different turn's ratio