Induction Motor - Torque Equation
Last Update: February 20, 2022
The machine starts out in torque mode (S=0), and remains in this mode for this test. The IM has a constant internally specified rotor resistance and is of the wound type. The damping B and inertia J are specified externally. The setup of the IM is much simplified such that there are no rotor resistance control (constant), no multi-mass to model the shaft masses, and mechanical torque is approximated by Tm = 0.8 * w^2, where the 0.8 means IM is running at 80% of full load (can be controlled via slider to adjust load torque).
User can switch between running the IM as a motor (Tm>0, w<1), or as a generator (Tm<0, w>1). The torque equations applies for both modes of operation. User can verify that the Te as output by the IM matches the Te_Calc as determined by the calculation.
Torque Equation:
Te - Tm = J*d(w)/dt + B*w
where:
Tm = Mechcanical torque
Te = Electrical torque based on terminal conditions
w (or w_m) = frequency of the rotor
J = inertia due to all moving parts of the machine shaft
B = mechanical damping