%% Starting a Synchronous Motor
%
% This example shows the starting procedure for a synchronous motor.
%
% Richard Gagnon (Hydro-Quebec)
% Copyright 1997-2012 Hydro-Quebec, and The MathWorks, Inc.
%%
open_system('power_smstarting')
%% Description
%
% When a synchronous motor is started, the excitation DC voltage is not applied to the field winding.
% The motor is started in induction machine mode with currents induced in the damper and field windings.
% A resistor is connected across the field winding in order to produce an acceptable field current and to limit voltage induced across the field winding.
% Then when speed reaches a preset value near synchronous speed, the field winding is connected to the DC voltage source
% and the motor synchronizes on the system frequency.
%
% In the synchronous machine model, the field winding terminals are not available. Instead, a Simulink(R) signal representing the field voltage must be applied at
% the Vf input of the machine. Therefore if the Vf input is left unconnected, a zero field voltage is applied on the rotor. In other words, the field winding is
% short-circuited. In this example, the field current (idf) and a gain block (R_start) are used to implement the resistance connected across the field winding.
%
% This model illustrates the starting prodcedure of a 60-kVA 400-V 50Hz synchronous motor. The motor is started at no load by closing the circuit breaker at t=0.1s .
% A 2 pu resistor is initially connected across the field winding.
% When the rotor speed reaches 0.99 pu, the "R_start" resistor is disconnected from the field terminals and it is replaced by the "Vf source" (1 pu).
% At the same time, the mechanical power is ramped from zero to 50% of the nominal mechanical power (Pm = -0.5 pu) in one second.
% The motor locks into step at synchronous speed (1 pu) at approximately t = 1.3 s.
%
%%
clear all
close all
bdclose all
