A DC power supply device includes a booster circuit generating boosted voltage obtained by boosting DC voltage output from a rectifier circuit and applying the boosted voltage to an inverter circuit, a control unit controlling operation of the booster circuit, and a current detection unit detecting current flowing into and from the inverter circuit. The booster circuit includes a charge accumulation unit including first and second capacitors connected in series and first and second switching elements connected in series. The booster circuit includes a switching unit including backflow prevention elements for preventing backflow of charges from the charge accumulation unit and a current detection unit detecting current flowing into and from the booster circuit. The control unit determines whether to continue driving of an electric motor based on each of detection values of the current detection units.

A pulse voltage generator calculates a corrected pulse voltage application time. The pulse voltage generator also outputs, for the duration of the corrected pulse voltage application time, a voltage vector closest to a rotor phase from among twelve voltage vectors as a voltage vector command. A current detector detects three-phase output currents of a power converter, which are obtained when first to sixth switching elements of the power converter are turned on or off on the basis of the voltage vector command. A three-phase/two-phase converter converts the three-phase output currents to two-phase output currents to output d-axis current. When the d-axis current after the corrected pulse voltage application time has elapsed becomes less than or equal to a demagnetization determination threshold value, a demagnetization determiner determines that demagnetization occurs in a permanent magnet of a rotor of a motor.

A pulse voltage generator calculates a corrected pulse voltage application time. The pulse voltage generator also outputs, for the duration of the corrected pulse voltage application time, a voltage vector closest to a rotor phase from among twelve voltage vectors as a voltage vector command. A current detector detects three-phase output currents of a power converter, which are obtained when first to sixth switching elements of the power converter are turned on or off on the basis of the voltage vector command. A three-phase/two-phase converter converts the three-phase output currents to two-phase output currents to output d-axis current. When the d-axis current after the corrected pulse voltage application time has elapsed becomes less than or equal to a demagnetization determination threshold value, a demagnetization determiner determines that demagnetization occurs in a permanent magnet of a rotor of a motor.

A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

A power conversion device includes: an inverter that converts a DC voltage into an AC voltage and drives a synchronous motor; and a magnetic pole position correction unit that corrects an error in a magnetic pole position of a rotor from a rotation angle sensor of the synchronous motor. The magnetic pole position correction unit includes an actual current phase calculation unit that calculates a current phase from a current when three-phase lines are short-circuited during rotation of the synchronous motor and an ideal current phase calculation unit that calculates an ideal current phase based on a rotational speed of the rotor and a temperature of a stator, and corrects the magnetic pole position from a difference between outputs of the actual current phase calculation unit and the ideal current phase calculation unit.

A motor drive monitors operation of a motor and adaptively track disturbances experienced by the motor. The motor drive receives a command signal and a cycle position signal. An estimated disturbance observed throughout a cycle of operation is stored in a look up table, and the motor drive uses the stored values as a feedforward value into a control module. The motor drive adaptively monitors operation of the motor and generates a new estimated disturbance value throughout each subsequent cycle of operation. The values of the estimated disturbance are updated within the look up table as a function of the new estimated disturbance values and of the previously stored values. The stored disturbance values adaptively track cyclic disturbances in the controlled machine or process and to reduce the effects of these cyclic disturbances on tracking error in the controlled machine or process.

A drive system for a BLDC motor having poles implemented by separate coils that are activated in corresponding phases, which comprises a controller for controlling the level and phase of input voltages supplied to the separate coils; a controlled inverter with outputs, for applying phase-separated input voltages to each of the separate coils at desired timing for each input voltage, determined by the controller; a power source for feeding power to the controlled inverter; an up/down DC-DC converter for converting the feeding power to the input voltages according to a command signal provided by the controller. The controller is adapted to sample the instantaneous angle of the rotor of the BLDC motor; sample the input voltage input voltage and the current of each phase to obtain the input power P; and for each input voltage, calculate the phase difference value that corresponds to the input power and feeds the phase difference value to the up/down DC-DC converter, thereby causing the up/down DC-DC converter to apply each input voltage to its corresponding coil at a specific timing for obtaining an optimal match between each input voltage and the current that is being built up in the corresponding coil.

A drive system for a BLDC motor having poles implemented by separate coils that are activated in corresponding phases, which comprises a controller for controlling the level and phase of input voltages supplied to the separate coils; a controlled inverter with outputs, for applying phase-separated input voltages to each of the separate coils at desired timing for each input voltage, determined by the controller; a power source for feeding power to the controlled inverter; an up/down DC-DC converter for converting the feeding power to the input voltages according to a command signal provided by the controller. The controller is adapted to sample the instantaneous angle of the rotor of the BLDC motor; sample the input voltage input voltage and the current of each phase to obtain the input power P; and for each input voltage, calculate the phase difference value that corresponds to the input power and feeds the phase difference value to the up/down DC-DC converter, thereby causing the up/down DC-DC converter to apply each input voltage to its corresponding coil at a specific timing for obtaining an optimal match between each input voltage and the current that is being built up in the corresponding coil.

a permanent magnet synchronous motor diagnostic device includes: a negative-sequence current calculator that calculates a negative-sequence current, based on magnitudes of a plurality of phase currents flowing through a permanent magnet synchronous motor that rotates a load; and a deterioration diagnoser that diagnoses deterioration of a plain bearing supporting the permanent magnet synchronous motor, based on the negative-sequence current.