Week 01
Electrical and Mechanical DC-Motor Models
I use my PSIM report and PI calculation file to revisit the DC-motor model, cascaded current-speed loops, and field weakening.
What I connect in this unit
The armature equation divides applied voltage among resistance drop, inductive voltage, and back EMF. The torque constant converts armature current into torque, while inertia and friction combine with load torque to determine speed change, so the electrical and mechanical equations must be solved together.
Concept map
- Armature equation
- Back EMF
- Torque constant
- Inertia and friction
Technical anchor
The coupled state model follows from V_a = R_a i_a + L_a di_a/dt + k_e omega and J d_omega/dt = k_t i_a - B omega - T_L.
How I review it
Write SI units for every parameter, remove derivative terms for no-load steady state and locked rotor separately, and verify signs and back-EMF direction against physical behavior.
Connection to the full course
Unit 1 of 12. Unit numbers follow the control structure in the saved design files and do not claim attendance weeks.