Motor controller for synchronously controlling multiple motors

摘要

A motor controller includes: a converter for converting an alternating current to a direct current; a first inverter for converting the direct current in a direct-current link of the converter to an alternating current for driving a first motor; a second inverter for converting the direct current in the direct-current link to an alternating current for driving a second motor; a power-failure detection unit for detecting a power failure on the side with the alternating-current power supply; and a command creation unit for creating a drive command for each of the first inverter and the second inverter when no power failure has occurred, while creating a drive command for the first inverter and also creating a drive command for the second inverter by using position feedback information of the first motor driven according to the drive command for the first inverter, when a power failure has occurred.

主权项

1. A motor controller for synchronously controlling at least two motors, the motor controller comprising:
a converter configured to convert an alternating-current power, supplied from a side with an alternating-current power supply, to a direct-current power and output the direct-current power; a first inverter connected to a direct-current link provided on a direct-current side of the converter, the first inverter configured to convert the direct-current power in the direct-current link to an alternating-current power for driving a first motor and output the alternating-current power, on the basis of a received command; a second inverter connected to the direct-current link, the second inverter configured to convert the direct-current power in the direct-current link to an alternating-current power for driving a second motor and output the alternating-current power, on the basis of a received command; a power-failure detection unit configured to detect whether or not a power failure has occurred on the side, with the alternating-current power supply, of the converter; and a command creation unit configured to
create, for each of the first inverter and the second inverter, a numerical-control-command-synchronization drive command for synchronously controlling the first motor and the second motor, when the power-failure detection unit does not detect any power failure, andcreate a master drive command for the first inverter and also create, for the second inverter, a slave drive command for synchronously controlling the first motor and the second motor by using position feedback information of the first motor driven according to the master drive command, when the power-failure detection unit detects a power failure, wherein the command creation unit includes a direct-current-voltage-maintaining-command creation unit for creating, as the master drive command, a direct-current-voltage maintaining command for controlling the first inverter so that a voltage in the direct-current link stays within a predetermined range, and the direct-current-voltage-maintaining-command creation unit is provided in the first inverter.