Project 1

The Matlab model is prepared using following equations

• To convert 3phase voltage to q-axis and d-axis
  Vsq = (2/3)*(u(1)*cos(u(4))+u(2)*cos(u(4)-(2*pi/3))+u(3)*cos(u(4)+(2*pi/3)))
  Vsd = (2/3)*(u(1)*sin(u(4))+u(2)*sin(u(4)-(2*pi/3))+u(3)*sin(u(4)+(2*pi/3)))
  
  
• To get stator fluxes lamdaqs & lamdads the equations are
  
  
  
  
• To get stator & rotor q and d currents the equations are
  
  
  
• To get rotor fluxes lamdaqr & lamdadr the equations are
• 
• To get torque the equations are
  
• Load torque is 0.83 times the rated torque as given in the question.

Rated torque = (9.5488*3.75*10^3)/1800

= 19.893

Load torque = 0.83 * 19.893

= 16.512

• To get Rotor speed the equation is
  
  
  
• To get the theta angle for different reference frame the equation is
  

As per the question :

a) To calculate start-up behaviour of the induction motor represented in the stationary reference frame the reference speed w is taken as 0.

• Vqs
• 
• Iqs & Ids
• 
• Iqs & Iqr
• 
• Te & Tl
• 
• Rotor speed
• 

b) To calculate start-up behaviour of the induction motor represented in the synchronous reference frame the reference speed w is taken as 1800*(2*pi/60).

• Vqs
• 
• Iqs
• 
• Iqr
• 
• Te & Tl
• 
• Rotor speed
• 

) To calculate start-up behaviour of the induction motor represented in the rotor reference frame the reference speed w is taken as wr.

• Vqs
• 
• Iqs
  
• 
• Iqr
• 
• Te & Tl
• 
• Rotor speed
• 

d) To calculate start-up behaviour of the induction motor represented in the rotor flux reference frame the reference speed w is taken as slip speed w(slip) = w(synch) - w(rotor).

• Vqs
• 
• Iqs
• 
• Iqr
• 
• Te & Tl
• 
• Rotor speed
• 

Above are the outputs for diefferent reference frames.

Result:

• The speed and torque slightly vaired with the different reference frames
• The speed decreased in order ROTOR FLUX>STATIONARY>SYNCHRONOUS>ROTOR reference frames
• Similarly torque increased in the same order as above.