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Induction machine with slip-ring rotor and main flux saturation.
The Saturable Induction Machine models main flux saturation by means of a continuous function. The model is implemented with machine equations in the stationary reference frame (Clarke transformation). Since the machine terminals have current-source characteristic, no external inductors may be connected. They must be included in the leakage inductances.
This machine model can be used with both the continuous and the discrete state-space method. To facilitate the discretization of the model the Integrator block is used which allows non-linear feedback in the circuit.
The machine operates as a motor or generator; the sign of the mechanical torque determines the mode of operation (positive for motoring, negative for generating). All electrical variables and parameters are viewed from the stator side. In the component icon, phase a of the stator and rotor winding is marked with a dot.
The electrical system of the machine model is implemented with state-variable
equations that are derived from the equivalent circuit in the stationary reference
frame. The value of the main flux inductance is not constant but depends on
the main flux linkage
as illustrated in the
diagram.
plsaturation(Lm0, Lmsat, PsiT, fT)
plots the main flux vs. current curve and the magnetizing inductance vs. current curve for the parameters specified.
The model accounts for steady-state cross-saturation, i.e. the steady-state magnetizing inductances along the d-axis and q-axis are functions of the currents in both axes. In the implementation, the stator currents and the main flux linkage are chosen as state variables. With this type of model, the representation of dynamic cross-saturation can be neglected without affecting the machine's performance. The computation of the time derivative of the main flux inductance is not required.
In order to inspect the implementation, please select the component in your circuit and choose Look under mask from the Edit menu. If you want to make changes, you must first choose Break library link and then Unprotect, both from the Edit menu.
Electromagnetic torque:
Mechanical rotor speed :
Mechanical rotor angle :
The output vector "m" contains the following 3 signals: