INDUSTRIAL AUTOMATION | Draw and explain power and control circuit of dc injection breaking for Induction motor.

 DC injection breaking for Induction motor: 

 An induction motor can be brought to rest quickly if ac supply to motor terminals is removed and instead a DC supply is applied.

 The DC current flowing through stator winding would produce the same no. of  stationary poles as the no. of poles of the revolving field produced with AC supply. 

 The rotor cut the flux of these stationary poles resulting in induced emf and current flow in the rotor winding. 

 The current flow in the rotor causes I2 R loss in winding resistance or in external resistance. 

 The rotor slows down as result of mechanical energy of rotation being converted into electrical energy and dissipated as heat. 

 Energy conversion would be complete when the rotor attains zero speed.