Analysis of open phase condition influence on an induction motor

Open phase faults can result in motor overloading due to unbalanced voltage. The present paper investigates different open phase conditions (OPCs) and their influence on an induction motor. The considered conditions include single and double line OPCs on the primary-side of a transformer supplying the motor. Several different transformer connections are investigated. The OPCs are first analyzed analytically with symmetrical components, after which the results are compared with simulated values. Measurements are performer to showcase the stator temperature evolution under OPC and to validate the numerical results. The results indicate that in the case of single OPC, only moderate unbalance is observed with YNd and YNyn transformer connection, whereas the highest phase current occurs with Dyn connection.