Model assumptions
Configuration of the machine electrical system
where
Ke = speed constant
ωm = mechanical angular speed
θ = mechanical angle
N = 90°/Step
Step = motor full size angle in degrees
The generated electromagnetic torque is:
where
Kt = torque constant
Td = detent torque
Parameter | Description |
---|---|
Armature inductance | Armature winding inductance in henries. Ls as shown in the configuration of the machine’s electrical system. |
Armature resistance | Armature winding resistance in ohms. Rs as shown in the configuration of the machine’s electrical system. |
Step angle | Step angle in degrees. Used to calculate N. |
Torque constant | Torque constant in N•m/A. If neither this value nor Ke are specified on the datasheet, Kt can be estimated from any sample on the static holding torque (Th) and rated current curve. |
Speed constant | Speed constant in V•s/rad. This is typically equal to Kt. This is Ke in the Ea1 and Eb1 equations. |
Detent torque | Detent torque in N•m. |
Shaft inertia | J<sub>rotor</sub> on the machine model diagram in <a href="/help/components/machine-modeling/">Machine modeling</a>. |
Shaft friction | This is F<sub>rotor</sub> on the machine model diagram in <a href="/help/components/machine-modeling/">Machine modeling</a>. |
Initial angular speed | Rotational measurement of the shaft angle in rad/s at the start of the simulation. |
Initial shaft angle | Initial shaft angle in radians. |