Performance Analysis of a Three-phase Induction Motor under Non- sinusoidal and Unbalanced Conditions

-As a result of the increasing use of electronic devices and other non-linear loads, the wave-forms of the electricity supply voltage are being distorted and inequalities are appearing between the phases. This deterioration is associated with problems of electromagnetic incompatibility and reductions in the efficiency of loads such as motors. This paper investigates the additional losses caused to induction motors when connected to supply systems which suffer from these distortions or inequalities. A specific formula is presented for the power factor associated with motors supplied by non-sinusoidal or unbalanced voltages; this has the characteristic of reflecting both the machine’s efficiency and that of the supply voltage.