Three-Phase Asynchronous Machine Starting

This example shows how to model a wye-delta starting circuit for an induction machine. After one second, the Controller subsystem closes the switch labeled S1. Closing this switch connects the supply to the machine. Initially, the machine connects to the supply in a wye configuration because the switch labeled S2 connects each phase of the ~1 port to the corresponding phase of the ~2 port and leaves the ~3 port unconnected. Once the machine is at 80% of the synchronous speed, S2 reconnects the machine in a delta configuration by disconnecting each phase of ~2 and connecting each phase of ~1 to the corresponding phase of ~3. The motor then operates in a delta configuration regardless of rotor speed. The supply sees a higher impedance when the motor is in wye configuration, reducing the starting current and causing less disruption to other connected loads.

Model