PMSM Field-Weakening Control

This example shows how to control the rotor angular velocity above the nominal velocity in a permanent magnet synchronous machine (PMSM) based electrical-traction drive. A high-voltage battery feeds the PMSM through a controlled three-phase converter. The Control subsystem includes a multi-rate PI-based cascade control structure which has an outer angular-velocity-control loop and two inner current-control loops. The velocity controller generates a torque reference. A zero d-axis controller converts this torque reference to current references. A field weakening controller adjusts the current references to satisfy the voltage constraints above the nominal velocity. A Stateflow® state machine implements the task scheduling in the Control subsystem. During the 0.7 s simulation, the angular velocity demand ramps up from 0 to 4000 rpm. The Scopes subsystem contains scopes that allow you to see the simulation results.

Model

Simulation Results from Simscape Logging

The plot below shows the requested and measured speed for the test, as well as the phase currents in the electric drive.