METHOD FOR CONTROL OF ASYNCHRONOUS MOTOR Russian patent published in 2014 - IPC H02P21/00 H02P21/12 H02P27/08 

FIELD: electricity.

SUBSTANCE: in the control method implemented in accordance with patent claim a preset frequency setting is stopped at change of input alternating voltage within wide range or change in the preset frequency setting; when current or voltage in a direct-current link reaches its critical values the inverter is switched off from the direct-current link till current or voltage in the direct-current link drops below the critical value. In case of change in frequency setting, start-up or shutdown of an asynchronous motor output voltage and frequency are changed according to the same law of scalar variable-frequency control. At inverter cut-off output voltage and frequency are reduced smoothly up to zero value and at restart the asynchronous motor is accelerated smoothly with current values of voltage and frequency in order to exclude generator mode at frequency drift.

EFFECT: simplifying algorithm for an asynchronous motor control at setting and resetting of the preset rotational frequency and at start-up of the asynchronous motor at frequency drift.

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