Fanuc Corporation

Youichirou Ooi

Norihiro Chou

Kiichi Inaba

Masaya Tateda

Akira Hirai

Hiroyasu Satou

A motor driving device includes: a converter unit having a capacitor; a plurality of inverter units having a plurality of semiconductor switching elements and configured to convert a capacitor voltage across the capacitor into an AC voltage to drive a plurality of motors; a second switch configured to connect the negative-side terminal of the capacitor to ground; a first detector configured to detect a ground-referenced voltage; and a second detector configured to detect the capacitor voltage. The motor driving device controls the semiconductor switching elements to establish a measurement state for enabling measuring of the insulation resistance of a measurement target motor, estimates a convergence value of the ground-referenced voltage based on multiple measurements of the ground-referenced voltage detected by the first detector, and then calculates the insulation resistance based on the estimated convergence value and the capacitor voltage.

Motor driving device and measuring method

A motor driving device includes: a converter unit having a capacitor; a plurality of inverter units having a plurality of semiconductor switching elements and configured to convert a capacitor voltage across the capacitor into an AC voltage to drive a plurality of motors; a second switch configured to connect the negative-side terminal of the capacitor to ground; a first detector configured to detect a ground-referenced voltage; and a second detector configured to detect the capacitor voltage. The motor driving device controls the semiconductor switching elements to establish a measurement state for enabling measurement of an insulation resistance of a measurement target motor, determines that the ground-referenced voltage has converged when an amount of change in the waveform of the ground-referenced voltage detected by the first detector becomes equal to or lower than a threshold, and calculates the insulation resistance based on the ground-referenced voltage and the capacitor voltage.

A motor driving device includes: an insulation resistance measuring unit configured to measure insulation resistance of a motor selected as a measurement target to thereby measure the insulation resistance of each of the multiple motors; a measurement interrupting unit configured to interrupt measurement of insulation resistance if a measurement interrupt condition is established; a storage unit configured to store information indicating the motor selected as the measurement target at the time of interruption of the measurement of insulation resistance; and a measurement resuming unit configured to, when measurement is resumed, resume measurement of the insulation resistance sequentially from the motor that had been selected as the measurement target when the measurement was interrupted, based on the information stored in the storage unit.

In a motor driver of the present invention, voltage and current values measured by a voltage and current detector and a voltage value measured by a voltage detector are determined as first measurement results, in the state of turning on semiconductor switching elements connected between a positive terminal of a capacitor and motor coils. Voltage and current values measured by the voltage and current detector and a voltage value measured by the voltage detector are determined as second measurement results, in the state of, as to a group A, turning on a semiconductor switching element connected between the positive terminal of the capacitor and the motor coil, and as to a group B, turning on semiconductor switching elements connected between a negative terminal of the capacitor and the motor coil. The insulation resistance values are calculated between the motor coils of each group A or B and a ground.

Motor driver having function of detecting insulation resistance

A motor drive apparatus according to the present invention comprises: an electric shunt which shunts a current flowing through a power line connected to a motor; a first current detection unit and a second detection unit, each disposed on either side of a node shunted by the electric shunt, for detecting the current flowing through the power line; a shunt commanding unit which gives a shunt command to the electric shunt to effect shunting of the current; and a determining unit which determines the presence or absence of a fault in the electric shunt, based on the shunt command and on current values detected by the first current detection unit and the second detection unit.

Motor drive apparatus having function of detecting failure of electric shunt

A motor drive device according to one embodiment of the present invention includes a converter () for converting an AC voltage input from a main power supply into a DC voltage, a DC link unit () for rectifying the DC voltage output from the converter, an inverter () for converting the DC voltage rectified by the DC link unit into an AC voltage for driving a motor using a semiconductor switching element, a voltage application unit () that is provided independently of the main power supply to apply a voltage to the DC link unit, a voltage detector () for detecting a voltage of the DC link unit after application of the voltage by the voltage application unit, and an abnormality determination unit () for determining the presence or absence of an abnormality of the DC link unit based on the voltage detected by the voltage detector.

Growing community of inventors

Yamanashi-ken, Japan

Youichirou Ooi