STUDYING PHASE BACK-EMF OF LOW POWER THREE PHASE LINE START PERMANENT MAGNET SYNCHRONOUS MOTORS BY A NUMERICAL TECHNIQUE

Abstract

Line start permanent magnet synchronous motors with high efficiency and
high power factor in steady state are meet the requirements of standards for high
efficiency motors. They will be a feasible solution for replacing partially squirrel
cage induction motors (SCIM) which widely used at the present time. Howerver,
their performance are mainly depended on the configuration of their rotor
configuration, sizes of permanent magnets, permanent magnet materials, phase
back-EMF value (E0),... In designing process, if the EMF value is not suitable for
motor, the efficiency of the motor will be down. Even, the efficiency of LSPMSM is
lower than SCIM with the same power. Therefore, this paper studies the effect of
rotor’s configuration on LSPMSM’s phase back-EMF waveform and determines
phase back-EMF value. This study will help the motor designers computing E0 and
modifying configuration of LSPMSM to reach appropriate E0 value.