This information is part of the Modelica Standard Library maintained by the Modelica Association.

This example demonstrates idealized field weakening of a quasistatic permanent magnet synchronous machine.

At standstill, the q-axis current is prescribed by a short ramp up to the nominal current. The d-axis current is controlled to keep voltage ≤ nominal voltage, while speed is varied up to four times nominal speed like in an automotive application. Total stator current is kept ≤ nominal total current. Simulate and plot versus smpm.wMechanical:

• fieldWeakeningController.vs: stator voltage
• fieldWeakeningController.is: stator current
• fieldWeakeningController.id: d-axis current
• fieldWeakeningController.iq: q-axis current

It can be seen that when field weakening begins negative d-axis current is increased from zero while the q-axis current current has to be reduced (current limit) to enable increase of the d-axis current (voltage limit).

Note

• The resistors connected to the quasi-static source model are necessary to numerically stabilize the simulation.
• Inertia of the machine is set to zero to enable a proper comparison of electrical and mechanical power.
• INominal denotes total nominal current, which can be applied without exceeding maximum temperature.