Here to talk about three-phase mathematical model of induction motors (squirrel cage motor)
as previously said before, when the above three-phase AC stator generating the stator current, the electron current generating a magnetic field, an equivalent circuit model of the motor, can be derived The rotor also induced voltage is generated because the rotor coils closed, the rotor current is generated, the rotor field is formed.
Whereby available, the model can be divided into three-phase induction motor voltage equation, flux equation, the torque equation and the equation of motion.
Voltage equations:
stator voltage equation:
Rotor voltage equation:
Written in a matrix equation, with P = d / dt:
Can be abbreviated to:
Similarly derivation flux equation:
torque equation:
equation of motion:
From the above equations, we can draw the following conclusions:
Ø voltage equation: we can see that the difference between the electromotive force and the magnetic strand exactly π / 2.
flux equation: we can only draw flux and current relationship.
torque equation: Torque strong coupling.
pump power equation: torque can be seen as a speed order inertia.
Precisely because of these characteristics, we hope to be more simple and intuitive flying analyze the relationship between the respective components of the motor, so we have to introduce the coordinate transformation, and PARK CLACK converting the AC component into a DC component for analysis forth.
