Fanuc Corporation

Akira Hirai

Masaya Tateda

Hiroyasu Sato

Kiichi Inaba

Shinichi Horikoshi

Shunsuke Matsubara

Youichirou Ooi

Yasusuke Iwashita

Naoyuki Suzuki

Hiroyasu Satou

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 includes a power source unit rectifying AC voltage to DC voltage and to smooth the DC voltage by a capacitor, a motor drive amplification, a power source voltage measurement unit, an insulation resistance deterioration detection unit having a contact unit connecting one end of the capacitor to the ground and a current detection unit provided between the other end of the capacitor and a motor coil, and detecting a deterioration in an insulation resistance of the motor based on a detected signal obtained from a closed circuit formed by the contact unit, the capacitor, the motor coil, and the ground by using the current detection unit, and a failure detection unit detecting a failure in the insulation resistance deterioration detection unit based on the detected signal in the insulation resistance deterioration detection unit and a voltage value measured by the power source voltage measurement unit.

Motor drive device including function to detect failure in insulation resistance deterioration detection unit of motor, and failure detection method

A motor drive device includes: a converter; a power supply; a plurality of inverter units configured to convert DC to AC to drive a plurality of motors by upper arm switching elements connected between a capacitor and motor coils and lower arm switching elements connected between the capacitor and motor coils; a second switch configured to connect the capacitor to the earth; a current detector configured to measure current flowing between the capacitor and the earth; a voltage detector configured to measure the voltage across the capacitor; and, an insulation resistance detector configured to detect insulation resistance of the multiple motors based on the current and voltage measured in a condition that the switching element to which the motor coil to be measured is connected is turned on and the switching elements to which a motor coil other than the target for measurement is connected are turned off.

Motor drive device having insulation resistance detecting function and method of detecting insulation resistance of motors

A motor drive includes a DC power supply unit for rectifying electric power supplied from an AC power supply using a rectifier and smoothing the electric power using a capacitor; and a plurality of independent voltage measurement circuits for measuring the voltage of the DC power supply unit. The motor drive, which converts a DC voltage into an AC voltage to drive a motor, includes a voltage collection unit for collecting voltage information obtained from the voltage measurement circuits; a normal operation voltage information storage unit for storing a normal operation voltage; and an abnormality determination unit for identifying an intersection voltage of output signals based on voltage values collected by the voltage collection unit, comparing the intersection voltage with the normal operation voltage, and detecting a broken portion owing to entering foreign matter based on the difference between the intersection voltage and the normal operation voltage.

Motor drive having function of detecting circuit abnormality owing to entering foreign matter before significant abnormality occurs

A motor drive device of the present invention includes: a rectification circuit configured to rectify an AC voltage; a power source unit configured to smooth a DC voltage by a capacitor; an inverter unit configured to drive a motor by converting a DC voltage into an AC voltage; a current detection unit configured to measure a current flowing through a resistor which is connected to a coil of the motor and the capacitor; a voltage detection unit configured to measure a value of a voltage across the capacitor; a second switch that grounds the capacitor; and an insulation resistance detection unit configured to detect an insulation resistance value of a motor by using two sets of a current value and a voltage value measured in two states where the second switch is turned off and turned on.

Motor drive device including insulation deterioration detection function and insulation resistance detection method of motor

Signals from a plurality of sensors (vibration sensors, temperature sensors, and humidity sensors) disposed at places on a machine are input through a communication circuit to a numerical controller that controls the machine. The numerical controller uses vibration information, temperature information and humidity information obtained from these sensors to determine whether the machine is in an abnormal state.

Numerical controller having a function for determining machine abnormality from signals obtained from a plurality of sensors

Disclosed is an insulation deterioration detection device that can accurately detect insulation deterioration in multiple motors by a simple circuit configuration. When detecting insulation deterioration, one end A of a smoothing capacitor is connected via a first switch to ground, and the other end B is connected via a second switch to motor windings; in this condition, link voltage is measured by a voltage measuring circuit provided in a converter unit, and the measured link voltage value is transmitted to a microcomputer in each inverter unit via serial communication. Current flowing via motor insulation resistance Z, Zis measured by a current measuring circuit provided in each inverter unit, and the microcomputer calculates the value of the insulation resistance Z, Zfrom the link voltage value and the current value.

Motor insulation deterioration detection device

Provided to the motor controller is means which can alter a conversion ratio with which a current value detected by a current detector is converted into a unit (such as voltage) easily usable in motor current control. According to the maximum current value of the motor and the demagnetization limit current of the motor, an optimum conversion ratio is selected and switched over. By making it possible to select and preset a conversion ratio, a plurality of motors can be controlled by one motor controller. Therefore, restrictions imposed on the combination of the motor controller and the motor are lightened.

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Yamanashi, Japan

Akira Hirai