Control device for AC motor

摘要

A control device for a three-phase alternate current motor includes: an inverter for driving the motor; current sensors for sensing current in the motor; and a control means having a feedback control operation part for operating a voltage command of each phase and switching the inverter based on the voltage command. When an absolute value of a sum of the current sensed values of three phases is larger than a threshold, the control means: executes a provisional current sensor system abnormality determination; generates a variation visualizing state, in which a response of a feedback control with respect to a variation in the current sensed value caused by the abnormality is delayed or stopped; and performs a phase identification processing for identifying the current sensor on a phase, in which an absolute value of a current deviation is larger than a threshold.

主权项

1. A control device for a three-phase alternate current motor, the control device comprising:
an inverter having a plurality of switching elements for driving the three-phase alternate current motor; a plurality of current sensors, each of which senses a current passing through a respective phase among three phases of the alternate current motor; and a control means that has a feedback control operation part for operating a voltage command of each phase so as to converge a deviation between a current sensed value sensed by a respective current sensor and a current command value of a respective phase to be zero and that switches on and off each switching element based on the voltage command of each phase so as to control the current passing through a respective phase of the alternate current motor, wherein, when an absolute value of a sum of the current sensed values of three phases is larger than a predetermined three-phase sum threshold value, the control means:
executes a provisional current sensor system abnormality determination, which indicates a possibility that an abnormality is generated in at least one of the current sensors;generates a variation visualizing state, in which a response of a feedback control with respect to a variation in the current sensed value caused by an occurrence of the abnormality in the at least one of the current sensors is delayed, or in which the response of the feedback control is stopped; andperforms a phase identification processing for identifying the at least one of the current sensors corresponding to a phase, in which an absolute value of a current deviation determined based on a difference between a current basic value and the current sensed value of the phase is larger than a predetermined deviation threshold value, in the variation visualizing state.