Abstract: A synchronous motor control device includes: a DC power supply; an inverter main circuit; a three-phase synchronous motor; and an inverter control unit that outputs a PWM signal used to control the inverter main circuit. The inverter control unit includes: a PWM signal generation unit; a start-up control unit that outputs a start-up voltage command value to the PWM signal generation unit at the time of start-up; a steady state control unit that calculates a steady state voltage command value in a steady state and outputs the value to the PWM signal generation unit; and a steady state control parameter initial value calculation unit that outputs an initial value of a control parameter to the steady state control unit such that an output voltage vector from the inverter main circuit to the three-phase synchronous motor is consistent before and after switching from the start-up to the steady state.

Abstract: A synchronous motor control device includes a voltage detector, a current detector, an inverter main circuit, and an inverter control unit. The inverter control unit includes: a phase current reproduction unit that reproduces a direct current into phase currents flowing to a permanent magnet synchronous motor; a current coordinate transformation unit that transforms the reproduced phase current into current on a control coordinate axis of a rotating coordinate system; a current control unit that calculates a voltage command value of the permanent magnet synchronous motor in such a manner that the current on the control coordinate axis equals a specific value; and a limiter unit that limits the value of the voltage command value.

Abstract: An inverter control device that controls an inverter unit that converts a DC voltage from a converter unit to an AC voltage and supplies the AC voltage to the DC motor includes a storage unit that stores therein information regarding a synchronization-loss limit; a synchronization-loss limit-current calculation unit that calculates the limitation value on the synchronization-loss limit current on the basis of the magnet temperature of the DC motor, the bus voltage to be applied to the inverter unit, and the information regarding a synchronization-loss limit; and a control unit that compares the primary current to be input to the converter unit with the limitation value and that, when the primary current exceeds the limitation value, outputs an adjustment command to adjust the operating frequency of the DC motor such that the primary current becomes equal to or less than the limitation value.

Abstract: A synchronous motor control device includes: a DC power supply; an inverter main circuit; a three-phase synchronous motor; and an inverter control unit that outputs a PWM signal used to control the inverter main circuit. The inverter control unit includes: a PWM signal generation unit; a start-up control unit that outputs a start-up voltage command value to the PWM signal generation unit at the time of start-up; a steady state control unit that calculates a steady state voltage command value in a steady state and outputs the value to the PWM signal generation unit; and a steady state control parameter initial value calculation unit that outputs an initial value of a control parameter to the steady state control unit such that an output voltage vector from the inverter main circuit to the three-phase synchronous motor is consistent before and after switching from the start-up to the steady state.

Abstract: A synchronous motor control device includes a voltage detector, a current detector, an inverter main circuit, and an inverter control unit. The inverter control unit includes: a phase current reproduction unit that reproduces a direct current into phase currents flowing to a permanent magnet synchronous motor; a current coordinate transformation unit that transforms the reproduced phase current into current on a control coordinate axis of a rotating coordinate system; a current control unit that calculates a voltage command value of the permanent magnet synchronous motor in such a manner that the current on the control coordinate axis equals a specific value; and a limiter unit that limits the value of the voltage command value.

Abstract: A power converting apparatus includes a rectifier converting alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit short-circuiting the alternating-current power supply via a reactor; and a controlling unit controlling the short-circuit unit in a half cycle of the alternating-current power supply. A correction amount using inductance of the reactor is set in the controlling unit, and the controlling unit changes, using at least a detection value of a power supply current and the correction amount, an ON time and an OFF time of a plurality of switching pulses, and controls, using changed switching pulses, an ON/OFF operation of the short-circuit unit.

Abstract: The device includes a rectifier circuit that converts alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit that short-circuits the alternating-current power supply via a reactor connected between the alternating-current power supply and the rectifier circuit; and a control unit that controls an ON/OFF operation of the short-circuit unit during a half cycle of the alternating-current power supply. The control unit includes a driving-signal generating unit that generates a driving signal Sa that is a switching pulse to control the ON/OFF operation of the short-circuit unit; and a pulse dividing unit that divides the driving signal Sa into a plurality of switching pulses.

Abstract: A power converting apparatus includes a rectifier that converts alternating-current power from an alternating-current power supply into direct-current power, a short-circuit unit that short-circuits the alternating-current power supply via a reactor, and a control unit that controls a short-circuit operation of the short-circuit unit. The control unit changes the number of times of the short-circuit operation during a half cycle of the alternating-current power supply on the basis of a load condition and sets a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply after the change of the number of times of the short-circuit operation to be different from a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply before the change of the number of times of the short-circuit operation.

Abstract: An inverter control device that controls an inverter unit that converts a DC voltage from a converter unit to an AC voltage and supplies the AC voltage to the DC motor includes a storage unit that stores therein information regarding a synchronization-loss limit; a synchronization-loss limit-current calculation unit that calculates the limitation value on the synchronization-loss limit current on the basis of the magnet temperature of the DC motor, the bus voltage to be applied to the inverter unit, and the information regarding a synchronization-loss limit; and a control unit that compares the primary current to be input to the converter unit with the limitation value and that, when the primary current exceeds the limitation value, outputs an adjustment command to adjust the operating frequency of the DC motor such that the primary current becomes equal to or less than the limitation value.

Abstract: A power converting apparatus includes a rectifier converting alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit short-circuiting the alternating-current power supply via a reactor; and a controlling unit controlling the short-circuit unit in a half cycle of the alternating-current power supply. A correction amount using inductance of the reactor is set in the controlling unit, and the controlling unit changes, using at least a detection value of a power supply current and the correction amount, an ON time and an OFF time of a plurality of switching pulses, and controls, using changed switching pulses, an ON/OFF operation of the short-circuit unit.

Abstract: The device includes a rectifier circuit that converts alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit that short-circuits the alternating-current power supply via a reactor connected between the alternating-current power supply and the rectifier circuit; and a control unit that controls an ON/OFF operation of the short-circuit unit during a half cycle of the alternating-current power supply. The control unit includes a driving-signal generating unit that generates a driving signal Sa that is a switching pulse to control the ON/OFF operation of the short-circuit unit; and a pulse dividing unit that divides the driving signal Sa into a plurality of switching pulses.

Abstract: A power converting apparatus includes a rectifier that converts alternating-current power from an alternating-current power supply into direct-current power, a short-circuit unit that short-circuits the alternating-current power supply via a reactor, and a control unit that controls a short-circuit operation of the short-circuit unit. The control unit changes the number of times of the short-circuit operation during a half cycle of the alternating-current power supply on the basis of a load condition and sets a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply after the change of the number of times of the short-circuit operation to be different from a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply before the change of the number of times of the short-circuit operation.

Abstract: A power converter includes step-up means for varying a voltage applied by a power supply to a predetermined voltage, commutating means for performing a commutation operation for allowing a current flowing through the step-up means to flow through a second path, smoothing means for smoothing a voltage related to outputs of the step-up means and the commutating means to produce power and supplying the power to a load side, and control means for performing control related to voltage varying, such as stepping up, by the step-up means and controlling the commutation operation of the commutating means on the basis of at least one of a voltage and a current related to the step-up means.

Abstract: A power converter includes step-up means for varying a voltage applied by a power supply to a predetermined voltage, commutating means for performing a commutation operation for allowing a current flowing through the step-up means to flow through a second path, smoothing means for smoothing a voltage related to outputs of the step-up means and the commutating means to produce power and supplying the power to a load side, and control means for performing control related to voltage varying, such as stepping up, by the step-up means and controlling the commutation operation of the commutating means on the basis of at least one of a voltage and a current related to the step-up means.