Abstract: An electric motor control device includes a direct current power source; an inverter interposed between an electric motor and the direct current power source, the inverter device controlling an exchange of electric power therebetween; an inverter control unit that generates PWM pulses having a duty ratio corresponding to voltage command signals and sends the PWM pulses to the inverter in order to switch the inverter; a frequency changing unit that changes a carrier frequency of the PWM pulses generated by the inverter control unit in a manner corresponding to a frequency control signal; and a motor control unit.

Abstract: A control device that controls a plurality of inverters respectively provided corresponding to a plurality of alternating-current electric motors so as to control the plurality of alternating-current electric motors by current feedback. The control device comprises a carrier frequency setting unit that individually selects and sets one of a plurality of carrier frequencies, each of which is a frequency of a carrier for generating switching control signals for the inverter based on a pulse width modulation method, for each of the plurality of inverters, and a switching timing table that specifies a switching timing serving as a permissible timing of switching to a different carrier frequency pair from each of a plurality of carrier frequency pairs each of which is composed of a combination of the carrier frequencies set for each of the plurality of inverters.

Abstract: A electric motor drive apparatus comprising a voltage control unit performing voltage control processing that determines alternating-current voltage command values serving as command values of the alternating-current voltages to be supplied to the alternating-current electric motor and generates switching control signals for the inverter; and a control mode selection unit selecting a synchronous control mode in which a cycle of electric angle of the alternating-current electric motor is synchronized with a switching cycle of the inverter, or an asynchronous control mode in which the cycles are not synchronized with each other. Current detection processing is performed to detect currents flowing in coils of the alternating-current electric motor in every standard calculation cycle that is set to a half of a cycle of the carrier.

Abstract: A control device that controls an electric motor drive device. The control device is configured with a first voltage control section that derives a modulation rate representing a ratio of an effective value of the voltage command values to the DC voltage and a voltage command phase. A second voltage control section generates a control signal for controlling the DC/AC conversion section on the basis of the modulation rate, the voltage command phase, and a magnetic pole position representing a rotational angle of a rotator of the AC electric motor. A computation cycle of the first voltage control section is set to be longer than a computation cycle of the second voltage control section.

Abstract: An electric motor drive control apparatus includes a detection angle obtaining section that obtains the detection angle of the resolver; a correction information storage section that stores correction information for correcting the detection angle, in association with a modulation ratio that is a ratio of an effective value of a fundamental wave component of the AC voltage to the system voltage; and a detection angle correcting section that obtains the correction information from the correction information storage section, based on the modulation ratio at the time the detection angle obtaining section obtains the detection.

Abstract: A rotary electric machine control system includes a battery electric power calculation unit for calculating battery electric power that is supplied from the battery; a torque limitation unit for limiting an output torque of the rotary electric machine; and a battery electric power abrupt variation estimation unit for estimating that the battery electric power is in an abrupt variation state in which the battery electric power is varying abruptly on the basis of at least one of a variation rate of the battery electric power and a variation rate of a rotational speed of the rotary electric machine.

Abstract: An electric motor control device includes an inverter that supplies an output of a primary-side DC power supply to an electric motor to control driving of the electric motor; a converter that includes a voltage increasing power supply device that increases a voltage of the primary-side DC power supply to supply the inverter with the increased voltage as a secondary voltage, and a regenerative power supply device that reversely supplies regenerative power from the inverter to the primary-side DC power supply; a secondary-side target voltage determination unit; a converter control unit; and an electric motor control unit.

Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during a powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.

Abstract: A dynamo-electric machine control system including a dynamo-electric machine and an inverter that is interposed between a battery and the dynamo-electric machine and that controls a current flowing through the dynamo-electric machine, wherein a rotation speed and an output torque of the dynamo-electric machine are controlled by the inverter, the dynamo-electric machine control system includes a battery power deriving unit that derives a battery power to be supplied from the battery when the dynamo-electric machine is operated at the rotation speed and the output torque; a limit power determining unit that variably determines a limit power, which is a maximum allowable value of the battery power, in accordance with a battery voltage; and a torque limiting unit that limits the torque of the dynamo-electric machine such that the battery power derived by the battery power deriving unit does not exceed the limit power.

Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.

Abstract: A control system includes an electric rotating machine; a driving circuit that is connected to a DC power supply, the driving circuit includes a frequency conversion unit configured such that, when the electric rotating machine is to be driven in a power running mode, the frequency conversion unit converts an output of the DC power supply into AC electric power, and when the electric rotating machine is to be driven in a regenerative operation mode, the frequency conversion unit converts an output of the electric rotating machine into DC electric power; and a control unit that controls the driving circuit, wherein the control unit judges whether a connection between the DC power supply and the driving circuit is being maintained, and is configured such that, when the connection is not being maintained, regenerative electric power generated by the electric rotating machine is reduced by controlling the driving circuit.

Abstract: An electric motor control device includes a direct current power source; an inverter interposed between an electric motor and the direct current power source, the inverter device controlling an exchange of electric power therebetween; an inverter control unit that generates PWM pulses having a duty ratio corresponding to voltage command signals and sends the PWM pulses to the inverter in order to switch the inverter; a frequency changing unit that changes a carrier frequency of the PWM pulses generated by the inverter control unit in a manner corresponding to a frequency control signal; and a motor control unit.

Abstract: In a closed loop control method of a linear vibration actuator which vibrates linearly and energized by a switching element driven in a PWM control method, a crest or peak point (Bc, Bp) of the back electromotive force occurring in the linear vibration actuator is detected (S14). The detected crest or peak point (Bc, Bp) is compared with a reference value (Bcr, Bpr) (S15), and adjusting the PWM duty (?) applied to the switching element and controlling the operating frequency of the linear vibration actuator to resonant frequency (S16 to S19), thereby keeping the crest or peak point (Bc, Bp) of the back electromotive force always constant.

Abstract: A discrete rotor position estimation method for a synchronized reluctance motor is provided. A d.c.-link voltage Vdc and a phase current Iph are sensed. A flux-linkage ?ph of an active phase is calculated from the sensed d.c.-link voltage Vdc and the sensed phase current Iph. The calculated flux-linkage ?ph is compared with a reference flux-linkage ?r. The reference flux-linkage ?r corresponds to a reference angle ?r which lies between angles corresponding to aligned rotor position and non-aligned rotor position in the synchronized reluctance motor. An estimated rotor position ?cal is obtained only once when the calculated flux-linkage ?ph is greater than the reference flux-linkage ?r.

Abstract: A method for sintering ceramic materials using a microwave hybrid heating system includes the steps of providing a ceramic member to be sintered, providing a microwave furnace, providing a thermal containment box comprising a material that is virtually transparent to microwave energy, providing at least one susceptor comprising a material that directly couples to microwave energy at room temperature substantially immediately within the thermal containment box, positioning the ceramic member within the thermal containment chamber proximate the susceptor, and irradiating the thermal containment box with microwave energy. The susceptor couples to the microwave energy and generates heat within the thermal containment box and the temperature of the ceramic member increases to the microwave coupling-trigger temperature, at which time the ceramic member couples directly to the microwave energy and is directly sintered by the microwave energy in cooperation with radiant energy from the one susceptor.

Abstract: A discrete rotor position estimation method for a synchronized reluctance motor is provided. A d.c.-link voltage Vdc and a phase current Iph are sensed. A flux-linkage ?ph of an active phase is calculated from the sensed d.c.-link voltage Vdc and the sensed phase current Iph. The calculated flux-linkage ?ph is compared with a reference flux-linkage ?r. The reference flux-linkage ?r corresponds to a reference angle ?r which lies between angles corresponding to aligned rotor position and non-aligned rotor position in the synchronized reluctance motor. An estimated rotor position ?cal is obtained only once when the calculated flux-linkage ?ph is greater than the reference flux-linkage ?r.

Abstract: In a brushless motor control method and a brushless motor controller in accordance with the present invention, a rotor rotation position detection means detects the time of the intersection of a detected induced voltage and an induced voltage reference value. In addition, a motor speed calculation means calculates the rotation speed of a brushless motor on the basis of the interval of the intersection times detected by the rotor rotation position detection means. Furthermore, a speed control means outputs a duty factor index on the basis of the deviation between the command speed and the rotation speed of the brushless motor. Still further, a switching signal generation means outputs switching signals to groups of switching devices on the basis of the rotation speed and the duty factor index at the time of the intersection.

Abstract: In a brushless motor control method and a brushless motor controller in accordance with the present invention, a rotor rotation position detection means detects the time of the intersection of a detected induced voltage and an induced voltage reference value. In addition, a motor speed calculation means calculates the rotation speed of a brushless motor on the basis of the interval of the intersection times detected by the rotor rotation position detection means. Furthermore, a speed control means outputs a duty factor index on the basis of the deviation between the command speed and the rotation speed of the brushless motor. Still further, a switching signal generation means outputs switching signals to groups of switching devices on the basis of the rotation speed and the duty factor index at the time of the intersection.

Abstract: Method and apparatus for facilitating the non-invasive study of a piezoelectric member, the method including the steps of generating a stress wave in the member at one point and sensing the magnetic field generated in the member at a second point distal to the first point. The apparatus includes an ultrasonic driver for generating the stress wave in the member, and a magnetic field sensor for sensing the generated magnetic field.