LOW-VIBRATION FREQUENCY-CONTROLLED ELECTRIC DRIVE AND METHOD OF CONTROLLING SAID ELECTRIC DRIVE Russian patent published in 2019 - IPC G05F1/253 

FIELD: physics.

SUBSTANCE: invention relates to conversion equipment, which is used in controlled electric drives, and can be used to simplify power circuits of frequency-controlled AC drives and to minimize the number of power semiconductor switches in their circuits. This device provides frequency control of asynchronous short-circuited electric motor by means of low-voltage voltage and frequency regulator installed in stator windings. Low-frequency variable-frequency electric drive comprises impulse voltage regulator made on the basis of three-phase booster transformer with three primary windings connected by star circuits and one common secondary winding. Regulator performs non-contact pulse-width control of voltage and frequency of stator voltage by means of three transistor keys, which perform functions of zero points in circuits of connection of primary windings of transformers according to the star circuit. Method of controlling a low-frequency variable-frequency electric drive is carried out by varying the frequency of alternating one-on-one connections of stator windings of an asynchronous motor at a period of stator voltage by switching three three-phase windmills of a three-phase booster transformer with an individual power transistor switch.

EFFECT: technical result of this technical solution consists in expansion of functional capabilities due to imparting properties of frequency-controlled electric drive to this device.

2 cl, 4 dwg