ANALYTICAL SOLUTION OF THE TRANSIENTS IN INDUCTION MOTORS DUE TO ASYMMETRICAL TERMINAL FAULT

ABSTRACT

When supply to the induction motor is short circuited the energy stored in machine, causes the machine to behave as a generator. This can result in very large transient negative torque and large transient current, especially in case of asymmetrical fault. This article provides an analytical solution of the transient current and the torque for the asymmetrical fault condition, and from these, practical equations are developed to determine the peak transient torque and the transient current. The analytical solution assumed constant shaft speed. The results obtained compared with the experimental results and with the machine exact deferential equation. It has shown that the results obtained agree well with both the theoretical results obtained from the numerical exact variable speed solution and the experimental results.