DC motors: dynamic model and control techniques Luca Zaccarian Contents 1 Magnetic considerations on rotating coils 1 1.1 Magnetic field and conductors .......................... 1 1.2 The magneto-motive force in a rotating coil .................. 2 1.3 The back EMF effect ............................... 5 2 The basic equations of the DC motor 6 2.1 The electric equations .............................. 7 2.2 The mechanical equations ............................ 8 2.3 Geared motors and direct drive motors ..................... 9 2.4 Block diagram of the DC motor ......................... 9 3 Stator voltage control with constant armature current 10 3.1 Steady state behavior ............................... 11 3.2 Transfer function ................................. 11 4 Stator voltage control with constant armature voltage 13 4.1 Linearized equations ............................... 13 4.2 Steady state behavior ............................... 14 4.3 Transfer function ................................. 14 5 Armature-Current control 16 5.1 Steady state behavior ............................... 16 5.2 Transfer function ................................. 17 5.3 Speed control system ............................... 18 5.4 Position control system .............................. 20 5.5 Torque control system .............................. 22