EFFECT OF ROTOR IMPEDANCE ON THE OPERATION OF THREE-PHASE INDUCTION MOTOR CONNECTED TO SINGLE-PHASE SUPPLY.

A three-phase induction motor operates very satisfactorily when connected to a single-phase supply. The voltage imbalance can be reduced to five percent with the normal cage rotor induction motor and a capacitor type converter. The study reported reveals that if a double-cage rotor is used instead of a single-cage, slip ring or deep bar rotor, the voltage imbalance can be reduced to two percent. This further improves the performance of the machine by reducing current imbalance, decreasing its heating and bringing down the noise level. The voltage across the capacitor is always less than the supply voltage to whcih the motor is connected.