The large current occurs in the stator winding of the induction motor when the terminals of the motor are short circuited in the three phases under steady running condition. In this paper, the equations calculating the short circuit current of the induction motor aer led based on the general equivalent circuits for the induction motor, which are described on the Laplace transform domain. The equations indicating the current in Laplace transform obtained from the equivalent circuit are transferred to the real domain. Thus, the precise and approximate equations are concluded. The constants regarding the primary and secondary winding of the induction motor are separated in the equations. Therefore, on case of the short circuit through the feeder cable, the current is capable of being calculated considering influence of the impedance of the feeder cable. As the result of calculating the short circuit current for the induction motor of marine use, it becomes clear that the approximate equation is practically useful.

View full abstract