Fanuc Corporation

Hiroyasu Sato

Shinichi Horikoshi

Akira Hirai

Masaya Tateda

Shunsuke Matsubara

Yasusuke Iwashita

Minoru Kobayashi

Mamoru Yaeshima

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 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

A data reception unit carries out reception of data, which consists of a combination of switching noise resistant states and switching noise nonresistant states, over a fixed serial communication time a plurality of times for each fixed serial communication period same as the one or a plurality of the switching periods. A serial communication time setting unit sets the serial communication time different from one or a plurality of the switching periods, based on the switching period, the serial communication period, and the communication speed of the data communication device, so that the starts of all of the switching periods within the serial communication time are consistent with the time of reception of the switching noise resistant state at the time of at least one of the reception of the data among a plurality of times of the reception of the data.

Data communication device that carries out serial communication in order to control motor

A motor drive apparatus includes an inverter which has an upper and lower arms each provided with a plurality of semiconductor switching devices and free-wheeling diodes connected in reverse parallel with respective ones of the plurality of semiconductor switching devices, wherein the semiconductor switching devices are controlled on and off to convert DC to AC, a short-circuiting unit which includes a selector switch between motor phase windings of a synchronous motor, the selector switch being opened and closed under the control of a command, and a dynamic braking control unit which, upon reception of a dynamic braking start command, performs control so as to turn on all of the semiconductor switching devices provided in either one of the upper and lower arms and to turn off all of the semiconductor switching devices provided in the other arm, and thereafter controls the short-circuiting unit so that the selector switch is closed.

Motor drive apparatus equipped with dynamic braking control unit

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

The drive of the motor is stopped, the electromagnetic switch contacts are switched OFF, and thereafter the first and second contact points are closed to form a closed circuit of the smoothing capacitor, second contact point, first and second resistors, motor coil, ground, ground, first contact point, and smoothing capacitor. Charging voltage of the smoothing capacitor is applied to the closed circuit. If an insulation resistance of the motor deteriorates, a current flowing through the closed circuit is increased. The increase of the current is detected by means of the potential difference across the first resistor Rin the closed circuit, to detect insulation resistance deterioration of the motor.

Insulation resistance deterioration detection method and insulation resistance deterioration detection device for motor, and motor driver

A motor driving apparatus capable of drivingly controlling a plurality of inverter units with a single motor driving command from a motor control unit, and thereby control a large-capacity motor or the like. The motor control unit sends out a single motor driving command (torque command) S. An intermediary unit obtains motor driving commands S&#xd7;Ato S&#xd7;Afor the inverter units by multiplying the motor driving command S by each of coefficients Ato Aset in advance. The inverter units are fed with the motor driving commands S&#xd7;Ato S&#xd7;Aindividually and drive a single motor. Since the motor is driven by the total current supplied by the inverter units, the motor can generate a large torque. The motor control unit only needs to generate a single motor driving command S, and hence only needs to operate a single processing part. Hence, the motor control unit can generate and send out motor driving commands for other motors to drive them.

Growing community of inventors

Yamanashi, Japan

Hiroyasu Sato