Induction motor response during bus transfer

The purpose of this study is to examine the electromechanical changes which occur in a three phase induction motor which is connected to a bus with other motors during a bus transfer from one supply to another and thereby predict the likelihood of motor damage to the machine under consideration.

Development of the d-q, two axis model on synchronously rotating axes from the conventional three phase model on stationary axes is presented. This model is then used in the simulation of an auxiliary power system bus in such a manner that the relative rotor flux phase position and magnitude of a single machine may be examined during a bus transfer with the effects of interconnected machines included in the simulation. The program also computes the resultant volts-per-hertz vector between motor and supply at the instant of reclosure to the supply.

This model has been implemented on a microcomputer and the sensitivity of the model to machine data imprecision has been investigated and is reported.