摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A motor controller capable of effectively utilizing electrical energy accumulated in a capacitor and achieving a reduction in capacitance of the capacitor. The motor controller includes a converter that receives an input AC voltage and performs AC-to-DC power conversion thereon, an inverter that receives DC power and performs DC-to-AC conversion thereon, and a capacitor and a charging/discharging control circuit connected in parallel with a DC link between the converter and the inverter. Electrical energy is supplied from the capacitor to the DC link via the charging/discharging control circuit. The charging/discharging control circuit has a circuit for discharging electrical energy accumulated in the capacitor and for stepping up a voltage of the capacitor when discharging the electrical energy.
摘要:
A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.