%% Saturation in Three-Phase Asynchronous Machine
%
% This example shows the effects of saturation in a three-phase asynchronous motor at various
% operating conditions.
%
% Jean-Nicolas Paquin and Louis-A. Dessaint (Ecole de Technologie
% Superieure, Montreal)
% Copyright 1997-2012 Hydro-Quebec, and The MathWorks, Inc.
%%
open_system('power_asm_sat')
%% Description
%
% The model shows two identical asynchronous motors rated 50 HP, 460 V, 1800 rpm. In order to compare the linear and saturated model,
% saturation is implemented in the top motor only. The stator is connected to an ideal three-phase source and load torque is kept constant
% Simulation is performed in phasor mode.
%
%% Simulation
%
% *1.* At no load (Tm =0), (three-phase source), simulate and observe the steady-state stator current for different values of stator voltage
% ranging from 0.5*nominal_voltage (230 Vrms L-L) to 1.5*nominal voltage (690 Vrms L-L).
% For the saturated motor, you should observe that each operating point lies ont the I_versus_V saturation curve specified by the Saturation Parameters.
% Obviously, a voltage value below the saturation voltage (first point supplied in the Saturation Parameters) will produce the same current for both motors.
%
% Observe the impact of saturation for different torque values ranging from zero to nominal torque (197 N.m).
%
% Note that during motor start up the 60-Hz component of current observed on the 'is_phase_A' scope model is higher for the saturated model.
%
% *2.* The locked rotor test is generally used to determine the approximate values of the rotor parameters.
% In that specific case where the slip is unitary, the impedance of the rotor branch becomes so low that the magnetizing
% current is negligible compared to the rotor and stator currents. Therefore, the magnetizing branch can be
% neglected and it can be assumed that the saturation has no influence.
%
% To simulate a locked rotor, specify an infinite inertia (J=inf in the machines' dialog boxes).
% Simulate with 460V source voltage (nominal voltage) and then 690V (1.5*nominal voltage).
% Observe both machines' stator currents in steady-state.
% You should observe stator currents for saturated and unsaturated motors, very close to each other.
% This shows that when the rotor of an asynchronous motor is blocked, saturation is negligible.
%
%%
clear all
close all
bdclose all
