Patent ID: 9543862
Date: 2017-01-10
CPC Classifications: G01R,H02H,H02P

Claim:
1. An electric motor control device comprising: an inverter circuit that supplies power to a plurality of electric motors connected in parallel with the inverter circuit; and a controller that controls the power supplied from the inverter circuit to each of the plurality of electric motors, wherein: the controller includes: a current command generator that generates a current command indicating a value of current supplied from the inverter circuit to the plurality of electric motors; a compensation calculator that outputs a voltage compensation signal for compensating a difference between a value of actual current supplied to each of the plurality of electric motors and a value of current indicated by the current command; a determiner that determines, based on a value obtained from the voltage compensation signal, whether or not an abnormality is occurring in at least one of the plurality of electric motors; and a shutdown controller that shuts down the power supply from the inverter circuit to each of the plurality of electric motors when a valid condition for improving accuracy of determination by the determiner is satisfied and the determiner determines that an abnormality is occurring; and the valid condition includes a rotational frequency of at least one of the plurality of electric motors being equal to or greater than a threshold value.