SYNCHRONOUS MOTOR DRIVE DEVICE

摘要

PROBLEM TO BE SOLVED: To execute step-out detection using a simple configuration while stably controlling a synchronous motor without using a position detector or an AC current detector.

SOLUTION: A voltage given from an inverter 11 to a motor 12 is calculated by a division by the impedance of a motor electric circuit comprising a resistor and an inductance of a motor winding in a drive frequency of the motor driven by the inverter as a reference current value for executing the step-out detection of the synchronous motor. The reference current value is compared with an inverter output current detection value calculated via the current detector 17 so as to determine as the step-out when the detection value exceeds the reference current value.

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