General - Delta vs Wye Phase Connections

The delta and wye motors provide the exact same performance in theory. The delta has a lower resistance, a lower torque constant and a higher current. The end result is that force/torque is exactly the same.

A delta winding is used if more speed is needed, and the winding can not be scaled, and more voltage is not available.

A delta winding should be avoided because it allows currents to circulate in a circle in the delta if the back emf wave form has odd harmonic content. This causes additional losses. Therefore, a scaled wye windings is better for high speed than a delta winding.

For a wye wound motor as compared to a delta wound motor, presuming each phase resistance is the same, between any two phases, a delta wound motor has 1/3 the resistance as compared to the wye.

The wye-wound has higher resistance and higher inductance, better for drives with lower switching frequencies.