| Patent application number | Description | Published |
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| 20090230898 | SERVO AMPLIFIER WITH REGENERATIVE FUNCTION - A servo amplifier for a robot capable of avoiding an excessive capacity for dealing with a regenerative power to achieve downsizing, cost reduction and energy saving of the device. A servo amplifier for driving servomotors of a robot to perform an operation using an electric power from a power source. The servo amplifier comprises a changeable converter connected with the power source and a plurality of inverters electrically connected with the converter and the servomotors. The changeable converter is selectively provided as a converter having a regenerative function of returning a regenerative power generated in the servomotors to the power source, or a converter having a regenerative function of discharging the regenerative power through a resistor, depending on conditions of the operation by the robot. | 09-17-2009 |
| 20100171511 | MOTOR INSULATION DETERIORATION DETECTION DEVICE - 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 | 07-08-2010 |
| 20110063122 | NUMERICAL CONTROLLER HAVING A FUNCTION FOR DETERMINING MACHINE ABNORMALITY FROM SIGNALS OBTAINED FROM A PLURALITY OF SENSORS - 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. | 03-17-2011 |
| 20110238338 | MOTOR DRIVING APPARATUS EASILY ANALYZABLE FOR CAUSE OF FAULT - Disclosed is a motor driving apparatus in which provisions are made so as to easily isolate the cause of a fault in the event of the occurrence thereof. The voltage and current in each phase of the AC power being supplied to a converter are detected, and the most recently detected data are stored in a power supply monitoring unit for a predetermined period of time. If an alarm occurs in the converter, inverter, or controller, the data currently held in the power supply monitoring unit are recorded in a recording unit. By displaying the thus recorded data, one can easily identify whether the cause of the alarm is due to the power supply or the motor driving apparatus itself. | 09-29-2011 |
| 20110241590 | MOTOR DRIVING APPARATUS HAVING FAULT DIAGNOSTIC FUNCTION - A motor driving apparatus capable of detecting during operation a ground fault and a phase-to-phase short circuit by distinguishing one from the other is provided while minimizing an increase in cost. The sum of three-phase AC currents supplied from a three-phase AC power supply to an AC/DC converter is detected by a current sensor. When overcurrent is detected by an overcurrent detector, if the sum of the currents detected by the current sensor is zero, it is determined that the fault is a phase-to-phase short circuit, but if the sum is not zero, it is determined that the fault is a ground fault. | 10-06-2011 |
| 20110260662 | MOTOR DRIVING APPARATUS HAVING FUNCTION OF DYNAMICALLY SWITCHING CONVERTER OPERATION MODE OF AC/DC CONVERTER - A motor driving apparatus is provided that performs AC/DC conversion by suppressing harmonics of the input at the time of normal operation, while on the other hand, allowing system operation to continue in the event of an overload by avoiding system stoppage. The motor driving apparatus, which drives a motor by supplying power from an AC power supply, includes: an AC/DC converter having a converter operation mode which is switched between a PWM converter operation mode in which an AC input voltage is converted into a DC voltage by applying PWM control to a plurality of power switching devices connected in serial and parallel fashion and a diode rectifier operation mode in which an AC input voltage is converted into a DC voltage by using a plurality of diodes each connected in reverse parallel with an associated one of the plurality of power switching devices; and a converter control unit which dynamically switches the converter operation mode of the AC/DC converter according to a load during powering of the motor. | 10-27-2011 |
| 20110298402 | MOTOR DRIVE DEVICE WITH FUNCTION OF SWITCHING TO POWER REGENERATIVE OPERATION MODE - A motor drive device comprising a converter for carrying out a power running operation for supplying power from a three-phase AC power supply to a three-phase AC motor and a power regenerative operation for returning energy generated by the three-phase AC motor to the three-phase AC power supply. The converter has power switching elements, a first power regenerative control unit for controlling an on/off action of the power switching elements at the time of carrying out the power regenerative operation by using pulse width modulation signal whose pulse width changes in accordance with a value indicated by a command signal; a second power regenerative control unit for controlling the on/off action of the power switching elements at the time of carrying out the power regenerative operation in order to generate respective power regenerative currents in a phase representing the maximum electric potential among three phases of the three-phase AC power supply and a phase representing the minimum electric potential among the three phases, and a power regenerative operation switching unit for switching control of the on/off action of the power switching elements at the time of carrying out the power regenerative operation between a control carried out by the first power regenerative a control unit and that carried out by the second power regenerative control unit. | 12-08-2011 |
| 20120056568 | MOTOR DRIVING APPARATUS HAVING DC LINK VOLTAGE REGULATING FUNCTION - A motor driving apparatus comprises: an AC/DC converter which converts AC voltage supplied from an AC power source into DC voltage through PWM switching control of a power switching device; and a DC/AC converter which converts the DC voltage into variable-frequency AC voltage for driving a motor in a controlled manner. The AC/DC converter includes: a control unit which generates, based on an error between the DC voltage and a DC voltage command value, a PWM signal for the PWM switching control of the power switching device; and a frequency/gain varying unit which sets the frequency of the PWM signal to be generated by the control unit and a control gain in the control unit higher than their normal levels during a period in which a load in the DC/AC converter varies. | 03-08-2012 |
| 20120068636 | MOTOR DRIVING APPARATUS - When the output of motor reaches or exceeds a predetermined value during acceleration of the motor, the control target value of the DC link voltage which is the voltage of a power storage device is gradually lowered in corresponding relationship to the motor output. When the motor enters a constant speed control mode, the DC link control target value is maintained at a constant level. When the motor enters a deceleration control mode, the DC link control target value is gradually raised in corresponding relationship to the motor output, and regenerative power is recovered by the power storage device and reused in the next control cycle. | 03-22-2012 |
| 20120068637 | MOTOR DRIVING APPARATUS - During motor acceleration control period that starts at time T | 03-22-2012 |
| 20130221888 | MOTOR DRIVE APPARATUS EQUIPPED WITH DYNAMIC BRAKING CONTROL UNIT - 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. | 08-29-2013 |
| 20140070743 | MOTOR DRIVE DEVICE WITH ALARM LEVEL SETTING UNIT - A motor drive device includes a converter which mutually converts power between AC power and DC power, an inverter which converts the DC power into AC power for driving a motor to output to a motor side, and converts regenerated AC power from the motor side into DC power to output to the DC side, a DC link unit which connects a DC side of the converter and a DC side of the inverter, a voltage detecting unit which detects a DC voltage value, an alarm level setting unit which sets an alarm level of the DC voltage value, an alarm determining unit which determines whether or not the DC voltage value exceeds the alarm level, and an alarm reporting unit which instructs the inverter to stop conversion operation when it is determined that the voltage value exceeds the alarm level. | 03-13-2014 |
