DEVICE FOR VARIABLE FREQUENCY DRIVE CONTROL Russian patent published in 2008 - IPC H02P23/14 H02P25/00 H02P27/04 

FIELD: electricity.

SUBSTANCE: invention is referred to electric engineering and may be used in automated AC drives with frequency converters. Device for variable frequency drive control includes controlled frequency converter consisting of non-controlled rectifier, filter and inverter, intensity reference input element, electromotive force (EMF) error sensor, voltage sensor and comparator unit. Control unit includes motor stator frequency controller and motor EMF controller, functional transmitter, which converts current motor voltage into current motor EMF value, rotor absolute slip input element, which inputs slip value defining motor moment in startup and brake modes of operation. Motor operation is controlled by inverter control unit operating from two input signals: control signal of stator field frequency controller to be supplied to the first rotor input from stator field frequency controller and control signal from motor EMF to be supplied to the second input from EMF controller. Depending on specific current EMF value, it is ensured that current stator field frequency value complies with current motor EMF value at any time and in all modes of operation. It is adequate to frequency control with inter-induction flux linkage constancy in motor rotor and stator.

EFFECT: creation of device to control variable frequency drive, which ensures current stator field frequency value compliance with current motor EMF value at any time and in all modes of operation but depending on specific current motor EMF value.

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