The electrical differential equations describing the
performance of an induction motor following supply disconnection are solved, analytically by assuming the motor speed to remain constant over very short steps of the
motor performance. The variation of the motor speed over
different steps is taken into account by numerically
integrating the mechanical equation of the motor at each
step of the solution. The results obtained by this method
coincide with those obtained by numerical integration of
both the electrical and mechanical equations. They also
show close agreement with experimental results of the
stator voltage of a 3-pbase 1.5 kW induction motor.