Abstract: A motor driving device controls driving of an inverter device, detects current values in two phases, and compensates a value. The motor driving device detects current values in two phases, namely, a maximum phase current value and a minimum phase current value, within a single cycle of a PWM carrier frequency. The motor driving device compensates a value obtained by subtracting an absolute value of a difference between two absolute values, namely, the detected maximum phase current value and minimum phase current value, from the smaller value of the absolute values, as the offset current component.

Abstract: In the drive device for a three-phase synchronous motor, if one of the two rotational position detectors is defective, it is necessary to identify the rotational position detector having abnormal output and is in the detective state. To do this, three or more rotational position detectors are required, which increases costs of the rotational position detectors. By comparing the outputs of two rotational position detectors, an abnormality of ether one of the two detectors is detected. The abnormal detector is identified with the use of rotational position estimating means. The drive of the three-phase synchronous motor is controlled with the use of the output ? of the properly functioning one of the first and second rotational position detectors.

Abstract: An object of the invention is to simultaneously solve a miniaturization and an improvement of productivity of a power conversion device, a temperature rise suppression of a smoothing capacitor, and a reduction of motor noises. The power conversion device of the invention includes a smoothing capacitor, a first power conversion unit and a second power conversion unit which are connected in parallel, and a control unit which generates a PWM pulse on the basis of an output voltage vector and a PWM carrier. The control unit includes a correction unit which corrects a predetermined output voltage vector value to two or more different output voltage vector values such that an average value in one period of the PWM carrier becomes the predetermined output voltage vector value. The correction unit corrects a first output voltage vector value in a first period, and corrects a second output voltage vector value in a second period different from the first period.

Abstract: To control an inverter in the event of an arm failure of a power converter, fluctuation in an output torque is suppressed, and reduction of a total output caused by the failure is suppressed by distributing an output into a plurality of inverters. A power converter for driving a redundant motor having a pair of first and second independent coils, includes: a first inverter circuit connected to the first coil; a second inverter circuit, independent from the first inverter circuit, connected to the second coil; and a first phase relay provided between the first inverter circuit and the first coil. When any one of a plurality of arms of the first inverter circuit fails, the first phase relay shuts off conduction between the failed arm and the first coil, and the redundant motor is driven by operating the second inverter circuit and the remaining arms of the first inverter circuit.

Abstract: A power steering device includes a steering mechanism, an electric motor for applying a steering assist force to the steering mechanism, and a first motor rotational position sensor for sensing as an actual axis phase a rotational position of a rotor of the electric motor. A control device is configured to: receive input of a signal of first actual axis phase outputted from the first motor rotational position sensor; receive input of a signal of value of electric current flowing through the electric motor; estimate as a control phase a phase of an induced voltage occurring in the electric motor, based on the signal of value of electric current; and determine whether or not the first motor rotational position sensor is abnormal, based on a difference between the first actual axis phase and the control phase.

Abstract: An object of the present invention is to provide an inverter driving device and an electric system which are capable of accurately detecting an offset amount of a current detection circuit that detects a motor current using a direct bus current, and compensating for the detected offset amount, to improve detection accuracy of the motor current and control the motor appropriately, without increasing the number of components of the inverter driving device.

Abstract: An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.

Abstract: An object of the present invention is to realize high-performance motor driving control by detecting DC currents to reproduce AC currents with high accuracy in an electric power converter in which a plurality of inverters are connected to a motor either independently or in parallel. The present invention is characterized in that a predetermined current detection period in which a first current detection section detects a DC current of a first inverter is controlled in such a manner that the predetermined current detection period does not overlap at least timing of changing over between on-timing and off-timing of a switching element that configures a second inverter. More preferably, the predetermined current detection period in which the first current detection section detects the DC current of the first inverter is controlled in such a manner that the predetermined current detection period does not overlap periods in which a current is carried to the second current detection section.

Abstract: Provided is a motor control device that realizes a high power drive and keeps a steering feeling having a good responsiveness with respect to an operation amount of a steering wheel like an electric power steering device while suppressing an input current to be equal to or lower than a predetermined value in response to a power source management as a vehicle. The motor control device of the invention includes an inverter which converts a DC input current from a DC voltage source into an AC current on the basis of a rotor phase of a motor and outputs the AC current. In a range in which an input current to the inverter does not exceed a predetermined upper limit while keeping a torque current, a maximum weak field current is calculated by a weak field current command calculation unit and is conducted.

Abstract: In the drive device for a three-phase synchronous motor, if one of the two rotational position detectors is defective, it is necessary to identify the rotational position detector having abnormal output and is in the detective state. To do this, three or more rotational position detectors are required, which increases costs of the rotational position detectors. By comparing the outputs of two rotational position detectors, an abnormality of ether one of the two detectors is detected. The abnormal detector is identified with the use of rotational position estimating means. The drive of the three-phase synchronous motor is controlled with the use of the output ? of the properly functioning one of the first and second rotational position detectors.

Abstract: An electric motor drive control device includes: an inverter circuit that converts DC power inputted via a DC bus to multiphase AC power and outputs the multiphase AC power to an electric motor; a current detector that detects a DC current flowing in the DC bus; a PWM generator that generates PWM signals and outputs the PWM signals to the inverter circuit; a current calculator that calculates a current value for each of phases to be flowed to the electric motor based upon a value of the DC current and the PWM signals; and a current controller that generates a command signal based upon the current value, and outputs the command signal to the PWM generator, wherein: if one of the phases of the AC power has become missing, the current calculator determines which phase is one that has become missing and calculates current values for other phases.

Abstract: An object of the invention is to simultaneously solve a miniaturization and an improvement of productivity of a power conversion device, a temperature rise suppression of a smoothing capacitor, and a reduction of motor noises. The power conversion device of the invention includes a smoothing capacitor, a first power conversion unit and a second power conversion unit which are connected in parallel, and a control unit which generates a PWM pulse on the basis of an output voltage vector and a PWM carrier. The control unit includes a correction unit which corrects a predetermined output voltage vector value to two or more different output voltage vector values such that an average value in one period of the PWM carrier becomes the predetermined output voltage vector value. The correction unit corrects a first output voltage vector value in a first period, and corrects a second output voltage vector value in a second period different from the first period.

Abstract: An objective of the present invention is to improve current detection accuracy and to reduce noise of carrier frequency. A motor apparatus and a motor drive apparatus calculate motor currents Iu, Iv, and Iw using a DC bus current detected value Idc of an inverter and control a magnitude and a phase of an applied voltage of a motor to drive the motor. A carrier adjuster decreases a carrier frequency Fc of the inverter if a motor output is relatively larger and that increases the carrier frequency Fc of the inverter if the motor output is relatively smaller. A pulse shift adjuster shifts an interphase waveform of a PWM pulse according to the carrier frequency Fc.

Abstract: An electric motor drive control device includes: an inverter circuit that converts DC power inputted via a DC bus to multiphase AC power and outputs the multiphase AC power to an electric motor; a current detector that detects a DC current flowing in the DC bus; a PWM generator that generates PWM signals and outputs the PWM signals to the inverter circuit; a current calculator that calculates a current value for each of phases to be flowed to the electric motor based upon a value of the DC current and the PWM signals; and a current controller that generates a command signal based upon the current value, and outputs the command signal to the PWM generator, wherein: if one of the phases of the AC power has become missing, the current calculator determines which phase is one that has become missing and calculates current values for other phases.

Abstract: The disclosed invention provides a synchronous motor driving system that reduces vibration attributed to a temporal second-order component of radial electromagnetic force in a three-phase synchronous motor and controls a d-axis current and a q-axis current to reduce noise that is produced as a result of vibration resonating with a structure. A motor driving system of the present invention causes a predefined negative d-axis current to flow into a motor in which a q-axis current is less than or equal to a predefined current value and d-axis inductance and q-axis inductance match substantially. The motor driving system causes a predefined negative d-axis current to flow into a motor in which d-axis inductance and q-axis inductance differ and causes the negative d-axis current to increase with an increase in the q-axis current.

Abstract: A drive system of a synchronous electrical motor includes a synchronous electrical motor; a power converter that is connected to the motor with a plurality of switching elements; a controller that outputs a voltage instruction to the power converter; a voltage detection unit for open phases upon application of respective positive and negative pulse voltages between respective two phases out of three-phase windings of the motor; an induced voltage difference for calculating an induced voltage difference that is a difference between an induced voltage detected by the voltage detection unit at each of the open phases upon application of the positive voltage pulse between the corresponding two phases and an induced voltage detected by the voltage detection unit at the open phase upon application of the negative voltage pulse between the two phases.

Abstract: In sequentially selecting and driving two phases of the three-phase stator windings of a synchronous motor, detect a speed electromotive voltage of a de-energized phase, relate the speed electromotive voltage to rotor position information beforehand, then count rotor position information backward based on the detected the speed electromotive voltage to estimate rotor position; and then detect rotation speed from the change rate of the rotor position information so as to achieve highly accurate position and speed control.

Abstract: An objective of the present invention is to improve current detection accuracy and to reduce noise of carrier frequency. A motor apparatus and a motor drive apparatus calculate motor currents Iu, Iv, and Iw using a DC bus current detected value Idc of an inverter and control a magnitude and a phase of an applied voltage of a motor to drive the motor. A carrier adjuster decreases a carrier frequency Fc of the inverter if a motor output is relatively larger and that increases the carrier frequency Fc of the inverter if the motor output is relatively smaller. A pulse shift adjuster shifts an interphase waveform of a PWM pulse according to the carrier frequency Fc.

Abstract: A synchronous electric motor drive system capable of driving at speeds near zero is provided. An energization mode determination unit switches six energization modes successively based on a terminal potential detected of the de-energized phase of a three-phase synchronous electric motor or on a stator winding wire connection point potential (neutral point potential) detected of the three-phase synchronous transmission unit. A voltage command correction unit corrects by a correction amount ?V an applied voltage command destined for the synchronous electric motor to supply the synchronous electric motor with a repeated waveform of a positive pulse, negative pulse, and zero voltage as a line voltage waveform of the energized phases in each of the six energization modes, the positive pulse voltage being polarized to cause the synchronous electric motor to generate a forward rotation torque, the negative pulse voltage causing the synchronous electric motor to generate a reverse rotation torque.

Abstract: The present invention relates to a drive apparatus and drive method for switching an energization mode when a voltage of a non-energized phase of a brushless motor crosses a threshold. In threshold learning, first, the brushless motor is stopped at an initial position. The brushless motor is then rotated by performing phase energization based on the energization mode from the stopped state. The voltage of the non-energized phase at an angular position of switching the energization mode is detected from a maximum value or a minimum value of the voltage of the non-energized phase during the rotation, and the threshold is learned based on the detected voltage. Alternatively, the brushless motor is positioned at the angular position of switching the energization mode by maintaining one energization mode, and then the energization mode is switched to the next energization mode.