Abstract: A motor drive includes a dynamic braking circuit for producing a deceleration torque utilizing a braking force caused by a synchronous motor acting as a generator when the synchronous motor is deenergized. The motor drive apparatus is equipped with a dynamic braking circuit fault detection capability, a DC power supply which is obtained by rectifying input AC power, voltage application function for applying a voltage to the windings of the synchronous motor and to the dynamic braking circuit for a predetermined length of time by switching power transistors connected to the DC power supply, current detection unit for detecting the value of a current flowing from the power transistors, and fault checking unit for checking the dynamic braking circuit for the presence or absence of a fault, based on the current value detected by the current detection unit and on a predefined threshold value.

Abstract: A motor driving apparatus having a converter, which receives AC voltage and converts it to DC power, and an inverter, which receives the DC power and converts it to AC power, includes a charge/discharge control circuit and a capacitor connected in parallel to a link section between the converter and the inverter, and energy stored in the capacitor C8 is charged and discharged at arbitrary timing by the charge/discharge control circuit. The invention thus provides a motor driving apparatus that supplies energy to a motor so that the peak of the input current from a power supply to the motor can also be suppressed when particularly large energy is needed during the second half period of motor acceleration.

Abstract: 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.

Abstract: A mechanical system includes a plurality of amplifier groups each having a common power source unit connected to a higher-level power source and a plurality of power supply units for supplying power to servo motors from the common power source unit. A servo motor drive control device of the mechanical system includes a plurality of amplifier group electric power detection units each determining an electric energy of the corresponding one of the amplifier groups.

Abstract: 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.

Abstract: A motor driving device that accurately achieves power failure detection according to a power failure tolerance with a relatively simple configuration. A counter input computing unit determines, as a counter input value, a value that is inversely proportional to the power failure tolerance determined from a voltage amplitude value and supplies the counter input value to a counter. The counter accumulates the input value at predetermined intervals and outputs an output value. A comparator determines that power failure occurs if the output of the counter 42 exceeds a threshold value.

Abstract: A controller controls the rotational speed of an induction motor, thereby controlling a spindle connected to the induction motor. Although an encoder for detecting the position of the spindle is mounted on the spindle, a speed detector is not attached to the induction motor. The speed of the induction motor is estimated from a spindle speed obtained by the encoder, and an excitation frequency command for the induction motor is determined based on the estimated speed.

Abstract: The controller controls a spindle connected to an induction motor via a belt by controlling the rotational velocity of the induction motor. The spindle has an encoder attached thereto for detecting the position of the spindle, but the induction motor does not have a velocity detector attached thereto. The velocity of the induction motor is estimated from the spindle velocity obtained from output of the encoder, and slip of the belt is detected based on the estimated velocity of the induction motor. When occurrence of slip of the belt is detected, the estimated velocity of the induction motor will not be used for the control of the induction motor.

Abstract: 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.

Abstract: A control device for a machine tool including a feed axis driving motor; a first power consumption calculating portion calculating power consumption of the feed axis driving motor; a second power consumption calculating portion calculating power consumption of equipment adapted to be operated by constant power; and a motor control portion determining a target time constant correlated with at least one of acceleration time and deceleration time of the feed axis driving motor, based on a summation of the power consumption calculated by the first power consumption calculating portion and the power consumption calculated by the second power consumption calculating portion, and controlling the feed axis driving motor based on the target time constant.

Abstract: A trajectory display device capable of correctly quantifying an error of a three-dimensional trajectory of a machine tool, and displaying or outputting the error. The trajectory display device has a command line segment defining part adapted to define a command line segment which connects two temporally adjacent points, in relation to each commanded position; an error calculating part adapted to define a normal line extending from the actual position to each command line segment and calculate an error of the actual position relative to a commanded trajectory, the error being determined as a shorter one between a length of a shortest normal line among the defined normal lines and a length of a line segment extending from the actual position to a commanded position which is the nearest from the actual position.

Abstract: Disclosed is a PWM rectifier in which switching losses in a semiconductor device are reduced without degrading the response of a control system. In a PWM overmodulation region, the modulation scheme is set to a three-phase modulation scheme. In other regions, a switchover condition such as the amplitude of an input current is acquired and compared with a switchover level. If the switchover condition equals or exceeds the switchover level, the modulation scheme is switched over to a modified two-phase modulation scheme which reduces the number of switching operations to two thirds for the same PWM frequency.

Abstract: A control device, for a servo die cushion, by which the speed of a die cushion is prevented from largely deviating from the speed of a slide, whereby the press force between the slide and the die cushion is not significantly reduced. The control device includes a slide speed detector for detecting the speed of the slide, a die cushion speed detector for detecting the speed of the die cushion, and a die cushion speed commanding part for controlling the speed of the die cushion. When a tentative speed command of the die cushion is largely deviated from the detected slide speed, the command of the die cushion is corrected such that the absolute value thereof does not exceed the value calculated by adding the absolute value of the detected slide speed to a positive constant.

Abstract: Coordinate values of a tool center point is calculated by obtaining coordinate values at each time of respective drive axes driven by a numerical controller. A tool radius compensation vector connecting the calculated tool center point at each time and an actual machining point is obtained. Then, coordinate values of the actual machining point are calculated based on the calculated coordinate values of the tool center point and the obtained tool radius compensation vector, and the trajectory of the actual machining point is displayed on a display.

Abstract: A motor driving device that accurately achieves power failure detection according to a power failure tolerance with a relatively simple configuration. A counter input computing unit determines, as a counter input value, a value that is inversely proportional to the power failure tolerance determined from a voltage amplitude value and supplies the counter input value to a counter. The counter accumulates the input value at predetermined intervals and outputs an output value. A comparator determines that power failure occurs if the output of the counter 42 exceeds a threshold value.

Abstract: A motor driving apparatus wherein provisions are made to ensure that the regenerative operation of a rectifier continues as long as the supply of power from an inverter continues, and that the regenerative operation of the rectifier stops when the supply of power from the inverter ends. The apparatus includes: a detection unit which detects an input voltage and current; an instantaneous effective power calculation unit which, based on the detected input voltage and current, calculates instantaneous effective power supplied from the rectifier to the inverter; a DC component calculation unit which, based on the value of the calculated power, calculates the DC component of the effective power; and a regenerative operation stopping decision unit which compares the value of the calculated DC component with a predetermined threshold value and decides that a power regeneration operation for feeding regenerative power from the inverter back into the power supply be stopped.

Abstract: A motor control apparatus that can calculate a proper amount of cogging torque compensation even in cases where components due to other factors than cogging torque (for example, components due to gravitational torque, etc.) are superimposed on a torque command being output during constant slow-speed feed operation.

Abstract: A servo motor controller having: a frequency identification section that performs analysis based on a frequency response method and identifies the frequency of a disturbance exhibiting a specified phase lag; an input/output gain identification section that identifies the input/output gain at the frequency identified by the frequency identification section; and a magnification factor resetting section that resets an adjustment magnification factor by performing a specified operation on a ratio between the identified input/output gain and a specified target value of the input/output gain.

Abstract: A motor driver for a machine tool, which comprises a fan motor, configured to drive a cooling fan for cooling a radiator or the interior of the motor driver, estimates a rate of heat release within a heating element or the motor driver, based on information obtained from a motor current detector used for motor control or from an input current detector of the motor driver, and adjusts a fan motor power supply voltage to control a rotational speed of the fan motor in accordance with the estimated heat release value.

Abstract: A motor drive system is provided with a plurality of axis control parts for outputting PWM commands using a position command, a plurality of current supply parts which supply current to the respective windings based on the PWM commands of the respective axis control parts, and which are connected to the respective windings, a motor position detector for outputting a signal of a rotor position of the motor, a first signal supply part for supplying the output signal to one current supply part of the plurality of current supply parts, and a second signal supply part for supplying the signal supplied through the first signal supply part to an axis control part corresponding to one current supply part, and the corresponding axis control part outputs a PWM command based on the signal supplied from the one current supply part through the second signal supply part to the corresponding axis control part and the position command, and the remaining axis control part outputs the PWM command based on the signal supplied f