Calculate slip speed of AC induction motor
Motor Control Blockset / Controls / Control Reference
The ACIM Slip Speed Estimator block computes the mechanical slip speed (difference between the synchronous speed and rotor speed) of the induction motor.
The block accepts the reference values of d- and q-axis currents and outputs the computed slip speed of the induction motor.
These equations describe the utilization of the slip speed value for field-oriented control (FOC) of the induction motor:
If we keep the rotor flux as constant and the d-axis is aligned to the rotor flux reference frame, then we can imply:
This block implements the preceding calculations as:
For detailed set of equations and assumptions, see Mathematical Model of Induction Motor.
is the electrical slip speed of the rotor (Radians/ sec).
is the mechanical slip speed of the rotor (Radians/ sec).
is the electrical speed corresponding to frequency of stator voltages (Radians/ sec).
is the rotor mechanical speed (Radians/ sec).
is the rotor electrical speed (Radians/ sec).
is the magnetizing inductance of the motor (Henry).
is the rotor resistance referred to stator (Ohms).
and are the reference stator d- and q-axis currents (Amperes).
is the rotor time constant (sec).
is the d-axis flux linkage of the rotor (Weber).
Isdref— Reference d-axis stator current
Reference d-axis stator current.
Isqref— Reference q-axis stator current
Reference q-axis stator current.
⍵mslip— Slip speed of induction motor
Mechanical slip speed of the rotor that the block computes.
Number of pole pairs— Number of pole pairs available in motor
2(default) | scalar
Number of pole pairs available in the induction motor.
Rotor resistance (Ohm)— Rotor resistance of motor
1.05(default) | scalar
Rotor resistance of the induction motor in Ohms.
Rotor leakage inductance (H)— Leakage inductance of rotor winding
6.81e-3(default) | scalar
Inductance due to leakage flux linked to the rotor winding (in Henry).
Magnetizing inductance (H)— Magnetizing inductance of induction motor
30e-3(default) | scalar
Inductance due to the magnetizing flux (in Henry).
Output saturation (rpm)— Saturation value for the block output
150(default) | scalar
Saturation value for the block output (in rpm).
Input units— Unit of input values
Per-Unit (PU)(default) | SI Units
Unit of the input values.
Base speed (rpm)— Base speed for per-unit system
1500(default) | scalar
Base speed (in rpm) for per-unit system.
To enable this parameter, set Input units to