The electric drive with indirect frequency converter and asynchronous motors with improved immunity against the supply voltage dips

This paper solves problematic of immunity against the voltage dips, of the power supply of the electric drive with induction motor supplied from the indirect frequency converter. There are demonstrated the several variants of adaptation of power circuits for achieving a higher immunity against the voltage dips of the power supply. First variant is using of the additional converter in DC-link. Second variant is using of the additional input converter. Third variant is using of active rectifier in place of common used non-controlled rectifier. The paper shows the results of measurement of first variant on laboratory.