Inverter control during overload and following power interruption

A frequency control method that interacts with a voltage-controlled current-regulated pulse-width modulated (VC-CRPWM) inverter to provide tripless operation during abnormal operating conditions is presented. Specifically, operation during and after a momentary overload and reconnection to a deenergized rotating motor under load is accomplished without experiencing overcurrent trips, knowledge of motor parameters, or velocity feedback. In addition, a stability study of the synchronous VC-CRPWM inverter that determines the effects of controller, motor, and load variations on the region of instability is performed.<
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