Constructing combined windings principle
Two winding systems can be combined together in an electrical machine in accordance with the existing types of winding configurations (Y and Δ). These systems are affected by voltages which form angles of 30, 60, 90 and 120 electrical degrees between vectors.
Accordingly, an electric motor having not a three-phase winding, but a six-phase one can be connected to a three-phase network.
To do this, one part of the winding should be connected in wye, and the other in delta. These windings placed in slots in such a way that resultant induction vectors of same-name Y and Δ phases form an angle of 30 electrical degrees between themselves.
Combination of two schemes in one winding allows improving field shape in the motor working gap and, as a result, significantly improving basic motor characteristics.
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