A three-phase synchronous motor with a salient-pole rotor. The rotor has distinct projecting poles, so the magnetic permeance differs along the direct and quadrature axes. Because of this, in addition to the main excitation torque there is an extra reluctance torque — the motor develops torque even without excitation and has a higher pull-out torque. The salient-pole construction is used for low-speed machines with many poles (hydro generators, slow drives). Like any synchronous motor it runs precisely in step. The model shows the torque M, the field current, the reluctance torque and whether it is in synchronism.
This page is a utility for simulating salient-pole synchronous motor (3-phase) online with specified initial values.
Using the model. Start the motor with the three stator switches; the damper winding runs it up and it pulls into step. Use the field rheostat to vary the rotor current — note that even with weak excitation the motor holds synchronous speed thanks to the reluctance torque (shown as Mrel in the caption). The speed is set only by the "supply frequency" slider. The "load torque" slider changes the load. Scopes: stator current I(stator), field current I(field) and voltage U(L1‑L2).
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