FREQUENCY CONVERTER CONTROL METHOD Russian patent published in 2012 - IPC H02P1/30 H02P27/06 H02H7/09 

FIELD: electricity.

SUBSTANCE: in frequency converter control method, when supply voltage fails, motor (7) rotates at the runout. When the network (1) is being restored, shaper (11) supplies signals to two (or three) channels (transistors) in various groups of inverter (6); current that exceeds the set point (approximately 200-300% of nominal motor current (7)) rises in two phases of motor. Under action of stator current pulse in rotor of motor there created is decaying current pulse and magnetic field that corresponds to it, which induces e.m.f. in stator windings, the frequency of which is equal to rotation frequency. Frequency of that signal is measured with unit (9) and transmitted to inverter (6) control unit (13). Repeated acceleration of electric motor (7) starts exactly from that frequency.

EFFECT: simplifying the construction and improving reliability.

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