FREQUENCY-CONTROLLED ELECTRIC MOTOR DRIVE Russian patent published in 1994 - IPC

FIELD: electrical engineering. SUBSTANCE: frequency-controlled electric motor drive has asynchronous motor with tacho generator put on shaft and windings manufactured in the form of resistively uncoupled sections, comparator, analog-to-frequency converter, former of phase harmonic functions, multipliers, power amplifiers each incorporating frequency converters built on A. C. keys and generator of voltage of constant amplitude and frequency. Frequency-controlled electric motor drive provides for control over speed of rotation of electric motor within wide limits due to formation of pulsating field with change of angular position which makes it possible to form low rotational speeds with keeping of high supply frequency. EFFECT: simplified design, expanded range of control with increased efficiency of electric motor drive. 5 dwg