US Patent No. 9,960,721

MOTOR CONTROL DEVICE PROVIDED WITH POWER FAILURE MANAGEMENT


Patent No. 9,960,721
Issue Date May 01, 2018
Title Motor Control Device Provided With Power Failure Management
Inventorship Koujirou Sakai, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,960,721

1. A motor control device which is connected to an AC power supply and used for a machine tool or an industrial robot which drives a driven body by controlling at least one motor, wherein the motor control device is provided with a power failure management function for use during an AC power supply failure at the time of driving the at least one motor, and wherein the at least one motor is controlled to perform at least one of stopping the at least one motor and retracting the driven body which is controlled by the at least one motor, the motor control device comprising:a first device including an AC-DC converter device equipped with a converter and DC link unit configured to convert AC power into DC power;
a second device connected to the first device including a DC-AC converter device and a control unit thereof, which is configured to output AC power to the at least one motor by converting DC power from the DC link unit into AC power by the DC-AC converter which is controlled by the control unit,
wherein:
the first device includes a power failure detection unit configured to detect power failure of the AC power supply at a time of driving the at least one motor and to generate a power failure detection signal in accordance with a detection of power failure, and a transmitter unit configured to transmit the power failure detection signal,
the second device includes a receiver unit configured to receive the power failure detection signal transmitted from the transmitter unit and transmit the detection signal to the control unit, and the control unit is configured to perform either stopping the at least one motor in response to receiving the power failure detection signal or retracting the driven body which is driven by the at least one motor, and
the motor control device further includes a plurality of additional second devices therein and each additional second device of the plurality of second devices is equipped with a receiver unit for receiving the power failure detection signal and configured to provide power failure management during power failure of the AC power supply;
when the power failure detection unit transmits a power failure detection signal during power failure of the AC power supply to a plurality of receiver units provided in each of the second device and the plurality of additional second devices, it is power failure management is provided in each of the second device and the plurality of additional second devices at the same timing of receiving the power failure detection signal, and power failure management is extended.