Abstract: A motor drive device capable of attaching a fan unit to a mounting member more easily. The motor drive device includes the mounting member formed with a mounting hole, the fan unit including a lid positioned facing the mounting member to cover the mounting hole and being fixed to the mounting member, and a restricting member movably attached to the lid, the restricting member being movable between a restriction position for engaging with the mounting member and a non-restriction position for releasing from the mounting member.

Abstract: A motor control device includes a rectifier which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for each motor and outputs it, an AC voltage detection unit which detects an AC voltage value on the AC input side of the rectifier, a state determination unit which determines that a voltage dropped state has been set when the AC voltage value is smaller than a certain specified voltage and that a normal state has been set when the AC voltage value is equal to or larger than the specified voltage, and an output control unit which controls each motor in accordance with the amount of voltage drop with respect to the specified voltage of the AC voltage value when the state determination unit determines that the voltage dropped state has been set.

Abstract: A motor drive device that inputs AC power from a power supply to drive a motor includes: a converter that converts the AC power from the power supply into DC power; a DC/DC converter that generates DC power produced by stepping-up, stepping-down, or stepping-up and stepping-down the DC power from the converter; an inverter that converts the DC power from the DC/DC converter into AC power and supplies to the motor; and an electrical storage capacitor that is provided between the DC/DC converter and the inverter.

Abstract: A motor drive of an embodiment of the present invention includes a PWM converter for converting AC power inputted from a low voltage AC power source into DC power by PWM control, an inverter for converting the received DC power to AC power to drive a motor, and a capacitor connected between the PWM converter and the inverter. The PWM converter is operated so as to limit input and output currents or input and output power to predetermined values, and supplied from the low voltage AC power source with a lower voltage than a voltage required to drive the motor. The PWM converter boosts a DC link voltage being an output voltage to the voltage able to drive the motor, and thereby serves to increase the potential difference of the capacitor between charged and discharged states to reduce the capacitance of the capacitor.

Abstract: A motor drive of an embodiment of the present invention includes a PWM converter for converting AC power inputted from a low voltage AC power source into DC power by PWM control, an inverter for converting the received DC power to AC power to drive a motor, and a capacitor connected between the PWM converter and the inverter. The PWM converter is operated so as to limit input and output currents or input and output power to predetermined values, and supplied from the low voltage AC power source with a lower voltage than a voltage required to drive the motor. The PWM converter boosts a DC link voltage being an output voltage to the voltage able to drive the motor, and thereby serves to increase the potential difference of the capacitor between charged and discharged states to reduce the capacitance of the capacitor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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 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: 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.

Abstract: During motor acceleration control period that starts at time T1, if power supply output or supply current exceeds a predetermined level at time T2, PWM control in a PWM converter is turned off until a deceleration control period of T3 to T4 ends. As a result, DC link voltage (voltage of a power storage device) at the start of the deceleration control at time T3 drops to provide space for storing regenerative power; since the PWM control in the PWM converter is off during the deceleration control period, the regenerative power can be stored into the power storage device and reused in the next control cycle.

Abstract: 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.

Abstract: 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.

Abstract: A motor drive device including a converter for a power running operation and a power regenerative operation. The converter has power switching elements, a first power regenerative control unit for controlling the power switching elements in the power regenerative operation by using pulse width modulation signal whose pulse width changes with a value indicated by a command signal; a second power regenerative control unit for controlling the power switching elements in the power regenerative operation to generate respective power regenerative currents in a phase representing the maximum potential among three phases of a three-phase AC power supply and a phase representing the minimum potential among the three phases, and a power regenerative operation switching unit for switching a control of the power switching elements in the power regenerative operation between a control by the first power regenerative control unit and a control by the second power regenerative control unit.

Abstract: 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.

Abstract: During motor acceleration control period that starts at time T1, if power supply output or supply current exceeds a predetermined level at time T2, PWM control in a PWM converter is turned off until a deceleration control period of T3 to T4 ends. As a result, DC link voltage (voltage of a power storage device) at the start of the deceleration control at time T3 drops to provide space for storing regenerative power; since the PWM control in the PWM converter is off during the deceleration control period, the regenerative power can be stored into the power storage device and reused in the next control cycle.

Abstract: 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.

Abstract: 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.

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.