3 Phase Permanent Magnet Motor

Check the simulator page for now.

Motor model parameters

  • [✓] rotor inertial mass
  • [✓] phase inductance L
  • [✓] phase resistance R
  • [✓] motor Kv constant
  • [✓] static friction torque (fixed torque at standstill)
  • [✓] dynamic friction torque (fixed torque when rotating)
  • [✓] resistance friction torque (this one is proportional to rotation speed)
  • [✓] battery internal resistance
  • [✓] mosfet resistance
  • [✓] mosfet reverse diode voltage drop
  • [✓] hall sensor toggle angle (the hall sensor senses positive magnetic field, so it toggles at almost 90 degrees difference from the rotor angle; the field is null at 90 degrees).
  • [✓] rotor mass (so we can measure axial deflection when motor is )
  • [✓] rotor axial restoration force constant
  • [ ] hysterisis modeling?
  • [ ] cogging torque ripple
  • [ ] do we want to model iron losses? https://uk.mathworks.com/help/sps/ref/pmsm.html

Measured/datasheet characteristics:

  • Rotor moment of inertia for 10g shell of 5mm radius: 0.00000025 Kg*m^2.
  • Forward diode voltage Vds = 0.72V (up to 1V); body-diode can withstand 4A continuous current.
  • Continuous drain current 8.5A (at high ambient temperature 70C).
  • Drain source ON resistance 18mΩ.
  • Phase winding resistance 1.3Ω (2.6Ω across 2 phases).
  • Shunt resistance 10mΩ.
  • Driver turn on propagation delay ~300ns.
  • Driver turn off propagation delay ~100ns.
  • Driver automatic deadtime ~200ns.
  • Phase inductance 0.1mH (0.2mH across 2 phases).

References: