Voltage Unbalance & Variations Impacts on IE4 Class LSPMM

The evolution of electric motors is increasing exponentially; it is currently possible to obtain efficiencies of around 96% with the IE4 efficiency class. A global interest in the transition to more efficient electric motors is being adopted in more countries through the Minimum Energy Performance Standards (MEPS), including Brazil, in which the minimum efficiency class level from August 2019 is the IE3 class, published in 2017 by Interministerial Ordinance No. 1. Considering the new energy scenario and aiming at new editions with greater efficiencies as minimum requirements, the present work presents a study of the voltage unbalance with under and overvoltage impacts on the performance of a Line Start Permanent Magnet Motor (LSPMM). The results show that the voltage unbalance with under voltages results in improvements in relation to the power factor, however voltage unbalance also results in increases in current harmonic distortion, therefore, this parameter must be analysed in systems with unbalance percentages greater than 1%.