Abstract: This is to reduce electromagnetic noise while reducing a calculation load of a microcomputer. An inverter drive device according to the present invention switches a first control mode, a second control mode, and a third control mode on the basis of vehicle speed information in a motor control device that controls a power converter that drives a polyphase motor by a PWM pulse signal based on a carrier signal, the first control mode being for updating a command voltage signal to the power converter only on a ridge side or a trough side of the carrier signal, the second control mode being for updating a command voltage signal to the power converter both on a ridge side and a trough side of the carrier signal, and the third control mode being for updating a command voltage signal to the power converter only once of ridge-trough-ridge or trough-ridge-trough of the carrier signal.

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 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: 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: Provided are an inverter device deterring PWM voltage error even if high inverter output frequencies are used for overmodulation driving and an electric vehicle equipped with the inverter device. In an angular section where the output voltage from an inverter device is linearly approximated with the zero cross point as the center thereof, a PWM generator in the inverter device changes either the time interval between the centers of PWM ON pulses or the time interval between the centers of PWM OFF pulses depending on the inverter operation state. An electric vehicle is equipped with the inverter device, which drives a motor.

Abstract: An inverter device includes a source current calculator and an inverter circuit, wherein: the source current calculator calculates an average value of the DC bus current Ical during a PWM cycle through arithmetic operation executed based upon instantaneous values of the DC bus current Idc of the inverter circuit; and the source current calculator provides an estimated value by designating the average current value Ical during the PWM cycle as an input source current Isrc during the PWM cycle.

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: Provided are an inverter device deterring PWM voltage error even if high inverter output frequencies are used for overmodulation driving and an electric vehicle equipped with the inverter device. In an angular section where the output voltage from an inverter device is linearly approximated with the zero cross point as the center thereof, a PWM generator in the inverter device changes either the time interval between the centers of PWM ON pulses or the time interval between the centers of PWM OFF pulses depending on the inverter operation state. An electric vehicle is equipped with the inverter device, which drives a motor.

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: According to the present invention, limited electric power is consumed so as to achieve long-lasting use of electric power during brake control with the use of an auxiliary power supply source when there is a malfunction of a vehicle power supply source. In addition, a brake control device for ensuring responsiveness at the beginning of braking or when emergency braking is necessary is provided. The brake control device of the present invention is a brake control device for detecting electric signals generated depending on the degree of brake-pedal operation and calculating the driver's demanded braking force based on the electric signals so as to generate the demanded braking force, which comprises an auxiliary power supply source for supplying electric power to the brake control device when there is a malfunction of a vehicle power supply source and controls braking depending on the charged capacity of the auxiliary power supply source.

Abstract: An electric motor drive device which drives an electric motor includes switching elements which are respectively connected to output lines and correspond to upper and lower arms of respective phases, a control unit which controls the operations of the switching elements, a smoothing capacitor connected in parallel with series circuits of the upper and lower arms of the phases, and an abnormality detection unit. The abnormality detection unit detects a voltage value of a virtual neutral point as a value related to the state of insulation of each of the output lines and detects a ground fault of the output line, based on a tilt of a temporary change in the detected value.

Abstract: An electric booster includes a housing having one end including a coupling surface where the housing is coupled to a master cylinder, and the other end including an attachment surface where the housing is attached to a vehicle. A controller includes a flat plate-like control board, and the control board is disposed so as to be positioned between a first plane including the attachment surface of the housing where the housing is attached to the vehicle, and a second plane including the coupling surface of the housing where the housing is coupled to the master cylinder.

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: An inverter device includes a source current calculator and an inverter circuit, wherein: the source current calculator calculates an average value of the DC bus current Ical during a PWM cycle through arithmetic operation executed based upon instantaneous values of the DC bus current Idc of the inverter circuit; and the source current calculator provides an estimated value by designating the average current value Ical during the PWM cycle as an input source current Isrc during the PWM cycle.

Abstract: A motor drive device inputs two detection signals from a rotation position sensor thereby to detect a rotation position, and controls a voltage to be applied to a motor according to the detected rotation position. The motor drive device has a control unit for outputting a first voltage in a first state in which the square sum of sampling values sampled from the two detection signals is a predetermined value, and outputting a second voltage in a second state in which the square sum is not the predetermined value.

Abstract: An oil-flooded screw compressor drives a pair of rotors at a rotational speed which is low enough not to increase torque for a short amount of time after start-up and accelerates the pair of rotors up to a normal-operation rotational speed after oil discharge. Alternatively, the oil-flooded screw compressor rotates the pair of rotors for a short amount of time after the remaining compressed gas is discharged after a halt, thereby allowing the oil accumulated inside the working chambers to be discharged and ensuring smooth start-up after the halt.

Abstract: A power conversion device includes a switching circuit with multiple series circuits having upper arm switching elements connected in series with lower arm switching elements, receives DC power to generate AC power for a permanent magnet motor; a control circuit that calculates a state of the switching elements based on input information for each control cycle, and generates a control signal for controlling switching elements according; and a driver circuit that generates a drive signal that renders the switching elements conductive or non-conductive on the basis of the control signal from the control circuit. The control circuit predicts a locus of a d-axial magnetic flux and a locus of a q-axial magnetic flux, and calculates the state of the switching elements so that the d-axial magnetic flux falls within a given d-axial magnetic flux fluctuation range, and the q-axial magnetic flux falls within a given q-axial magnetic flux fluctuation range.