Precise assessment of induction motor performance based on NEMA definition

In this paper, the shortcoming of NEMA definition for performance analysis of induction motor under supply voltage unbalance is presented. It gives a large range of performance variation. In order to make it suitable for the purpose the index is proposed, which along with NEMA definition can be utilized for the reduction of voltage variation and exact assessment of performance of induction motor. The performance of this index along with the NEMA definition is tested for various motor performance indices such as peak stator current, derating factor. The variations in the performance of the motor can be reduced with suggested voltage unbalance index. These facts are investigated by conducting various experiments on MATLAB Simulink software package.