METHOD TO PROVIDE FOR OPERABILITY OF THREE-PHASE ASYNCHRONOUS ELECTRIC DRIVE Russian patent published in 2011 - IPC H02H7/09 H02P27/02 

FIELD: electricity.

SUBSTANCE: invention refers to the sphere of electric engineering and may be used in asynchronous electric drives. Phase windings of stator of three-phase asynchronous electric motor are supplied from frequency converter operating in the mode of current source, which is realised by control of phase currents, at the same time settings for phase currents of motor are received from outlet of speed controller, to inlets of which a signal of rotation frequency setting is sent, as well as current frequency of rotation of motor shaft received from speed sensor. Simultaneously analysis of phase currents of motor is carried at each interval of pulse-width modulation, and in case a failure is detected on one of motor phases, current frequency is changed in two remaining phases k times according to previously introduced non-linear dependence of coefficient k from specified frequency of motor shaft rotation, and instantaneous values of phase currents of asynchronous motor are adjusted.

EFFECT: provides for operability of three-phase asynchronous motor in case of emergency disconnection of one of phases with preservation of motor shaft rotation frequency relative to three-phase mode of operation.

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