Abstract: A control device for an electric motor includes a control circuit that controls an operation of an inverter circuit on the basis of a voltage command value corresponding to a difference between a current command value calculated on the basis of the position of a rotor of the electric motor, and a current flowing through the electric motor. A current estimation unit estimates the current flowing through the electric motor by substituting the voltage command value, a parameter unique to the electric motor, and a rotational speed calculated on the basis of the position of the rotor into a voltage equation serving as a model of the electric motor. An LR estimation unit estimates an inductance and a resistance of the electric motor serving as parameters on the basis of the difference between the current obtained by a current acquisition unit and the current estimated by the current estimation unit.

Abstract: There is provided a control device for an electric motor. The control device includes an inverter circuit and a control circuit. In a control cycle of the electric motor, the control cycle includes first to third sections. The control circuit outputs a first modulated wave in accordance with an output of the electric motor and outputs a minimum value or maximum value of a carrier wave as second and third modulated waves in the first section with a peak of first alternate-current voltage, and outputs the second modulated wave in accordance with an output of the electric motor and outputs the minimum value or maximum value of the carrier wave as the first and third modulated waves in the second section with a peak of second alternate-current voltage. The same output is applied in the third section with a peak of third alternate-current voltage.

Abstract: A controller for an electric motor comprises: an estimator configured to estimate a position of a rotor by using a d-axis current, a q-axis current, a d-axis voltage command value, and a q-axis voltage command value from which a noise is removed by a filter having a first time constant when a torque command value is equal to or greater than zero, and estimate a rotational speed of the electric motor and the position by using the d-axis current, the q-axis current, the d-axis voltage command value, and the q-axis voltage command value from which a noise is removed by a filter having a second time constant smaller than the first time constant when the torque command value is less than zero

Abstract: A control device for an electric motor includes a control circuit that controls an operation of an inverter circuit on the basis of a voltage command value corresponding to a difference between a current command value calculated on the basis of the position of a rotor of the electric motor, and a current flowing through the electric motor. A current estimation unit estimates the current flowing through the electric motor by substituting the voltage command value, a parameter unique to the electric motor, and a rotational speed calculated on the basis of the position of the rotor into a voltage equation serving as a model of the electric motor. An LR estimation unit estimates an inductance and a resistance of the electric motor serving as parameters on the basis of the difference between the current obtained by a current acquisition unit and the current estimated by the current estimation unit.

Abstract: A control device for an electric motor includes: an inverter circuit configured to drive a rotor of the electric motor by a result of a comparison between a carrier wave and a voltage command value; and a control circuit configured to determine the voltage command value in every control period by vector control by using a current flowing through the electric motor, and a rotational speed and a position of the rotor. The control circuit is configured to shorten the control period as the rotational speed of the rotor or a modulation factor corresponding to the rotational speed of the rotor increases.

Abstract: There is provided a control device for an electric motor. The control device includes an inverter circuit and a control circuit. In a control cycle of the electric motor, the control cycle includes first to third sections. The control circuit outputs a first modulated wave in accordance with an output of the electric motor and outputs a minimum value or maximum value of a carrier wave as second and third modulated waves in the first section with a peak of first alternate-current voltage, and outputs the second modulated wave in accordance with an output of the electric motor and outputs the minimum value or maximum value of the carrier wave as the first and third modulated waves in the second section with a peak of second alternate-current voltage. The same output is applied in the third section with a peak of third alternate-current voltage.

Abstract: A pulse pattern generation device generating a pulse pattern for controlling switching elements provided in an inverter that operates a motor, the pulse pattern generation device includes a current calculation unit that calculates a current flowing through a coil when a voltage that is applied to the motor during the operation of the motor is virtually applied to the coil of the motor, an effective current calculation unit that calculates an effective current from the current calculated by the current calculation unit, an iron loss estimation unit that estimates an iron loss which originates in a core of the motor, and a pattern generation unit that generates a pulse pattern using an evaluation function including the iron loss estimated by the iron loss estimation unit and the effective current calculated by the effective current calculation unit as evaluation items.

Abstract: An inverter device includes an inverter circuit that has switching elements configuring an upper arm and a lower arm of each of U, V, W-phases, a signal generator that generates signals having waveforms corresponding to signals of U, V, W-phase command voltages, a first calculation unit that calculates an effective line voltage, a second calculation unit that generates a modulation voltage every control period, and a comparison unit that compares the signals with signals of the modulation voltage every control period, and outputs signals having pulse patterns which operate the switching elements of the upper arm and the switching element of the lower arm in the inverter circuit.

Abstract: A pulse pattern generation device generating a pulse pattern for controlling switching elements provided in an inverter that operates a motor, the pulse pattern generation device includes a current calculation unit that calculates a current flowing through a coil when a voltage that is applied to the motor during the operation of the motor is virtually applied to the coil of the motor, an effective current calculation unit that calculates an effective current from the current calculated by the current calculation unit, an iron loss estimation unit that estimates an iron loss which originates in a core of the motor, and a pattern generation unit that generates a pulse pattern using an evaluation function including the iron loss estimated by the iron loss estimation unit and the effective current calculated by the effective current calculation unit as evaluation items.

Abstract: An inverter device includes an inverter circuit that has switching elements configuring an upper arm and a lower arm of each of U, V, W-phases, a signal generator that generates signals having waveforms corresponding to signals of U, V, W-phase command voltages, a first calculation unit that calculates an effective line voltage, a second calculation unit that generates a modulation voltage every control period, and a comparison unit that compares the signals with signals of the modulation voltage every control period, and outputs signals having pulse patterns which operate the switching elements of the upper arm and the switching element of the lower arm in the inverter circuit.

Abstract: This power output device is provided with: a field winding; a motor having a plurality of star-connected motor windings composed of three or more phases; a capacitor; an inverter circuit configured to perform power conversion on the power supplied from the capacitor and to supply the converted power to the motor windings; a battery connected to the field winding; and a control unit. The inverter circuit has a plurality of switching element pairs that correspond to the respective motor windings. The capacitor is connected to a positive bus bar and a negative bus bar. The field winding is connected to the positive or negative bus bar and to a neutral point of the motor. The control unit is configured to control the switching element pairs so as to charge the capacitor by boosting the voltage of the battery and to supply a direct current to the field winding.

Abstract: This motor driving device is provided with a direct-current power supply, an inverter, and a noise filter. The noise filter is provided with: a choke coil, wherein a first winding and a second winding are wound on a common core, and the first winding is inserted into a positive electrode bus; and two capacitors connected in series between the positive electrode bus and a negative electrode bus. One end of the second winding is connected to a neutral point of a three-phase motor, and another end of the second winding is connected to a wire between the two capacitors.

Abstract: An electrical motor device according to the present invention is provided with a control unit. The control unit is configured to adjust the ratio of transformation by adjusting the ratio between a first time period, in which all upper-arm-side switching elements are on and all lower-arm-side switching element are off, and a second time period, in which all upper-arm-side switching elements are off and all lower-arm-side switching elements are on, and to select one of a plurality of driving modes for each control cycle. The plurality of driving modes include: a dual-driving mode including the first time period and the second time period in one control cycle during electrical motor driving; and an electrical motor driving mode not including the first time period and the second time period in one control cycle during electrical motor driving.

Abstract: This power output device is provided with: a field winding; a motor having a plurality of star-connected motor windings composed of three or more phases; a capacitor; an inverter circuit configured to perform power conversion on the power supplied from the capacitor and to supply the converted power to the motor windings; a battery connected to the field winding; and a control unit. The inverter circuit has a plurality of switching element pairs that correspond to the respective motor windings. The capacitor is connected to a positive bus bar and a negative bus bar. The field winding is connected to the positive or negative bus bar and to a neutral point of the motor. The control unit is configured to control the switching element pairs so as to charge the capacitor by boosting the voltage of the battery and to supply a direct current to the field winding.

Abstract: This motor driving device is provided with a direct-current power supply, an inverter, and a noise filter. The noise filter is provided with: a choke coil, wherein a first winding and a second winding are wound on a common core, and the first winding is inserted into a positive electrode bus; and two capacitors connected in series between the positive electrode bus and a negative electrode bus. One end of the second winding is connected to a neutral point of a three-phase motor, and another end of the second winding is connected to a wire between the two capacitors.

Abstract: An electrical motor device according to the present invention is provided with a control unit. The control unit is configured to adjust the ratio of transformation by adjusting the ratio between a first time period, in which all upper-arm-side switching elements are on and all lower-arm-side switching element are off, and a second time period, in which all upper-arm-side switching elements are off and all lower-arm-side switching elements are on, and to select one of a plurality of driving modes for each control cycle. The plurality of driving modes include: a dual-driving mode including the first time period and the second time period in one control cycle during electrical motor driving; and an electrical motor driving mode not including the first time period and the second time period in one control cycle during electrical motor driving.

Abstract: A power conversion apparatus includes a power conversion element; a capacitor; a control circuit that outputs a control signal to control operation of the power conversion element at the time of driving a load; a discharge control unit that outputs a discharge control signal to control operation of the power conversion element at the time of discharging the capacitor; a power supply circuit that generates a power supply voltage, on the basis of a voltage between both ends of the capacitor; and a driver unit that outputs a driving signal to operate the power conversion element, on the basis of the control signal or the discharge control signal. The power conversion element is operated according to the discharge control signal, a current is flown from the capacitor to the load through the power conversion element, and the capacitor is discharged.

Abstract: A power conversion apparatus includes a power conversion element; a capacitor; a control circuit that outputs a control signal to control operation of the power conversion element at the time of driving a load; a discharge control unit that outputs a discharge control signal to control operation of the power conversion element at the time of discharging the capacitor; a power supply circuit that generates a power supply voltage, on the basis of a voltage between both ends of the capacitor; and a driver unit that outputs a driving signal to operate the power conversion element, on the basis of the control signal or the discharge control signal. The power conversion element is operated according to the discharge control signal, a current is flown from the capacitor to the load through the power conversion element, and the capacitor is discharged.

Abstract: An electric power converter which has improved accuracy in compensation of a dead time. A motor driving system employing the electric power converter is also provided. A power module includes a plurality of switching devices connected in series and converts DC power to AC power. A control circuit produces a voltage command value in accordance with a control command inputted from the exterior, and produces gate signals to drive the switching devices of the power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation. A dead time compensation logic circuit calculates a final dead time compensation voltage based on a change rate of the voltage command value, a gain (dead time compensation voltage value), and a polarity of a current, the gain being calculated from a DC voltage value supplied to the electric power converter, a dead time, and a switching frequency.

Abstract: An electric power converter which has improved accuracy in compensation of a dead time. A motor driving system employing the electric power converter is also provided. A power module includes a plurality of switching devices connected in series and converts DC power to AC power. A control circuit produces a voltage command value in accordance with a control command inputted from the exterior, and produces gate signals to drive the switching devices of the power module corresponding to a final voltage command value which is obtained from the voltage command value with dead time compensation. A dead time compensation logic circuit calculates a final dead time compensation voltage based on a change rate of the voltage command value, a gain (dead time compensation voltage value), and a polarity of a current, the gain being calculated from a DC voltage value supplied to the electric power converter, a dead time, and a switching frequency.