Abstract: A disclosed motor driver control device is configured to control a plurality of switching devices that drive a motor. The motor driver control device includes a duty control unit configured to restrict a duty of a first pulse width modulation signal generated by comparing an oscillator signal generated at a predetermined cycle and a pulse generator signal so as to generate a second pulse width modulation signal, and a switching device control signal generator unit configured to include a logic circuit that operates the second pulse width modulation signal as a clock and configured to generate a switching device control signal controlling the plurality of switching devices based on the clock of the logic circuit of the switching device control signal generator unit.

Abstract: An object of the present invention is to provide an inverter device for driving an electric motor, which allows control stability and efficiency to be ensured over a wide region of the speed of the electric motor. The inverter device includes a rotational-speed detection section which detects a rotational speed of the electric motor, a carrier-frequency calculation section which calculates a carrier frequency on the basis of the detected rotational speed, and a carrier-frequency switching section which switches, on the basis of the calculated carrier frequency, the carrier frequency used for performing PWM control on the electric motor. The carrier-frequency calculation section calculates, as the carrier frequency, a frequency increased with an increase in the electric-motor rotational speed detected by the rotational-speed detection section.

Abstract: To suppress a ripple contained in current flowing into a DC power supply during one-pulse control in a motor drive apparatus receiving electric power from the DC power supply. A motor drive apparatus 1 includes an inverter control device (10) provided with a one-pulse control mode in which, during one electrical angle cycle, a positive rectangular pulse voltage and a negative rectangular pulse voltage are applied, as gate drive signals, to a switching element corresponding to each phase. When performing the one-pulse control mode, the inverter control device (10) gradually increases or reduces a duty in a predetermined phase angle width at rising and falling edges of the rectangular wave voltage.

Abstract: An electric motor driving apparatus having a failure detection circuit includes: a bridge circuit driving an electric motor; a PWM control circuit generating voltage instruction for driving the electric motor; a PWM signal generation circuit generating a PWM signal; a DC current detection circuit detecting DC current of the bridge circuit; a phase current calculation circuit calculating output phase current of the bridge circuit, based on the DC current and PWM signal; and a failure detection circuit detecting failure of the DC current detection circuit. The failure detection circuit determines failure of the DC current detection circuit from the DC current detected values in a zero voltage period in which the high-potential-side arms of the bridge circuit are all ON and in a zero voltage period in which the low-potential-side arms are all ON.

Abstract: A PCU drives a motor generator using electric power from a power storage device. The PCU includes a power conversion device, a capacitor and a control unit. When detecting a crash, the control unit drives the power conversion device and discharges charges remaining in the capacitor. Each of a plurality of reverse conducting-type semiconductor elements included in the power conversion device is integrally formed of a first semiconductor element operating as a switching element and a second semiconductor element operating as a free wheeling diode. In response to detection of the crash of a vehicle, the control unit changes a voltage applied to a gate terminal of the first semiconductor element and increases an electric power loss during a current-circulating operation by the second semiconductor element. As a result, the remaining charges stored in the capacitor in the drive apparatus is discharged as soon as possible.

Abstract: A distributed-arrangement linear motor in which stators are arranged in a distributed manner and a method of controlling the distributed-arrangement linear motor are provided. The linear motor 1 is a linear motor in which a stator and a movable member are relatively movable, wherein the stator and the movable member respectively have periodic structures in which plural kinds of poles of the stator and the movable member (12a, 12b, 12c) (22a, 22b, 22c) which magnetically act each other and arranged periodically subsequently in an order according to the arrangement in a direction of the relative motion therebetween; a plurality of stators are arranged in a distributed manner in the direction of the relative motion; a distance D1, D2 between adjacent stators is not more than a length Lmv of the movable member; the pole of the stator is formed of a coil 11; and a current control unit that controls current to be supplied to the coil based on the distance between the stators is provided.

Abstract: An electric motor controller system for modulating requested motor torque via oscillating the instantaneous torque, including a bi-stable torque controller; a proportional-integral (PI) velocity controller a proportional-integral-differential (PID) position controller; and sinusoidal zero-velocity table mapping.

Abstract: Included are: a voltage command generation unit which generates a voltage command amplitude and a voltage command phase based on a current command value; a phase generation unit during rectangular wave energization, which generates a voltage command phase during rectangular wave energization; and a control switching determination unit which switches by determining as to which control of PWM energization or rectangular wave energization will be performed depending on the amount of the condition of a motor. A switching device unit is driven by the output from a PWM energization unit when switched to the PWM energization; and the switching device unit is driven by the output from a rectangular wave energization unit when switched to the rectangular wave energization. The voltage command generation unit calculates the voltage command amplitude and the voltage command phase by using parameters of the motor.

Abstract: A method and apparatus for controlling an electric motor. A switching frequency meeting a desired operating condition is identified from information relating to operation of the electric motor. A switching of a current supplied to the electric motor with the switching frequency identified is controlled.

Abstract: A motor control device includes a PWM signal generating unit comparing PWM command voltage and carrier wave with each other to generate pulse signal so that duty is increased or decreased in both directions of phase lag and phase lead with one phase within carrier period as reference regarding one phase of three-phase PWM signal. The unit generates pulse signal so that duty is increased or decreased in one of the directions with one phase as reference regarding another phase. The unit generates pulse signal so that duty is increased or decreased in direction reverse to the one direction with one phase as reference regarding the other phase. The unit generates three-phase PWM signal pattern so that a current detecting unit is capable of detecting two-phase current in synchronization with advent of two predetermined time-points within carrier wave period of PWM signal with first to third phases being normally fixed.

Abstract: The present invention performs pulse shift control in such a manner that a difference between switching timings of PWM duty signals can reach or exceed a second predetermined value when the difference between the switching timings of the PWM duty signals of phases falls below the first predetermined value, and determines a correction amount for the phase by the pulse shift control in such a manner that a correction amount after switching becomes smaller than a correction amount before the switching of a phase on which the pulse shift control is performed in pulse shift phase switching control.

Abstract: In a motor, a stationary member is provided with a number M (M is a positive integer) of first poles within 360 electrical degrees at spaces therebetween. A plurality of windings are at least partly wound in the spaces, respectively. A movable member is movably arranged relative to the stationary member and provided with a number K (K is a positive integer) of second poles. The number K of second poles is different from the number M of first poles. A unidirectional current supply unit supplies a unidirectional current to at least one of the windings so as to create an attractive force between at least one of the first poles and a corresponding at least one of the second poles to thereby move the movable member relative to the stationary member.

Abstract: A control device for an induction machine includes an angle determining device designed to determine a rotor angle of the induction machine without requiring use of sensors. The angle determining device generates measuring voltage pulses which can be selectively used to replace control voltage pulses used to control the induction machine. Machine currents generated by the measuring voltage pulses can be used to determine a rotor angle without interrupting the control voltage pulses and/or operation of the induction machine.

Abstract: A control apparatus for an AC rotary machine includes: a current detection section detecting current from a power converter to the AC rotary machine; and a control section generating a three-phase AC voltage instruction to the power converter, based on current detected by the current detection section and a torque instruction. The control section includes: an observer calculating a magnetic flux estimated value of the AC rotary machine, based on detected current and the voltage instruction; a current instruction calculation unit calculating current instruction values on rotational two axes, based on the torque instruction and the magnetic flux estimated value from the observer; and a voltage instruction calculation unit calculating the voltage instruction, based on the current instruction values from the current instruction calculation unit and the magnetic flux estimated value from the observer.

Abstract: A motor control unit includes: a microcomputer that outputs a motor control signal; a driving circuit that supplies driving electric power to the motor based on the motor control signal; and a capacitor provided at an intermediate portion of a power supply line that connects the driving circuit and a driving power supply to each other. The microcomputer carries out electric discharge from the capacitor by supplying electric power generated by electric charges stored in the capacitor to the motor such that torque is generated by the motor and an angular velocity of the motor becomes less than or equal to a prescribed angular velocity, with torque transmission between the motor and the wheel interrupted by the clutch after a driving relay is turned off.

Abstract: A control apparatus for a switching circuit includes a controller, a target-rotational-speed acquiring device, a target-torque acquiring device, and an ON-time varying device. The controller is configured to turn on a bidirectional conduction switching device provided parallel to a reverse conducting device through which a commutation current flows. The target-rotational-speed acquiring device is configured to acquire a target rotational speed of an alternating current motor. The target-torque acquiring device is configured to acquire a target torque of the alternating current motor. The ON-time varying device is configured to vary, on a basis of the target rotational speed and the target torque, an ON time period during which the bidirectional conduction switching device provided parallel to the reverse conducting device through which a commutation current flows is turned on.

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 PWM output apparatus includes a calculating circuit configured to calculate an output width of a PWM output signal of a first signal and a second signal, which have phases different from each other, based on a command value of a PWM output. A comparing circuit compares the output width and a reference period which is set longer than a predetermined dead time period. A PWM output signal generating circuit outputs the PWM output signal to a dead time inserting block as a corrected PWM output signal, when a set/clear signal generating circuit outputs the set signal, and carries out a correction of setting the first signal of the PWM output signal to be inactive to output to the dead time inserting block as the corrected PWM output signal, when the set/clear circuit outputs the clear signal. The dead time inserting block corrects the corrected PWM output signal.

Abstract: Some embodiments provide a system that generates a coil switching signal for a brushless DC motor. During operation, the system determines a magnetic field of the brushless DC motor at a first time and a magnetic field of the brushless DC motor at a second time. Then, the coil switching signal is generated based on a relationship between the magnetic field determined at the first time and a first predetermined threshold, and the magnetic field determined at the second time and a second predetermined threshold.

Abstract: A motor control device includes a PWM signal generation unit configured to increase/decrease duty to both leading and lagging sides regarding a phase in which the duty becomes maximum among three-phase PWM signals. The unit is also configured to increase/decrease the duty to one of leading and lagging sides regarding a phase in which the duty becomes minimum. Regarding a phase in which duty is intermediate between the phases, the unit is configured to increase/decrease duty to the other of the leading and lagging sides based on the phase, thereby generating a three-phase PWM signal pattern so that a current detection unit is capable of detecting two-phase currents at two time-points fixed within a carrier period of the PWM signal respectively. A duty compensation unit is configured to increase/decrease before and after switching to change an increasing/decreasing direction of three-phase duties, increasing/decreasing the duties to compensate for the duties.

Abstract: [Problem] An object of the present invention is to provide a motor controlling apparatus that comprises a single current sensor and obtains a maximal duty range that current becomes detectable with realizing size reduction, weight saving and cost reduction and an electric power steering apparatus using the same.

Abstract: A DC brushless motor includes a rotary actuation shaft having multiple poles. Each of the poles has multiple commutation steps. The DC brushless motor also includes a motor controller capable of controlling rotation of the rotary actuation shaft. The motor controller stores a commutation step map.

Abstract: An electric compressor controller includes a compressor that compresses refrigerant of an air conditioning system; a motor that drives the compressor; an inverter that selectively control switching elements based on PWM pulse signals to supply drive power to the motor and heats the refrigerant by heat generated due to switching of the switching elements during a heating operation; temperature detectors each detects junction temperature of each of the switching elements; a drive controller that supplies the pulse signals to the inverter to control the inverter; and a slope varying unit that variably controls precipitous degree of rising/falling slope waveforms of the pulse signals based on the junction temperature detected by the temperature detectors. According to the electric compressor controller, efficiency for heating refrigerant is improved, so that its own heating ability is improved.

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: A method and a control device operate a three-phase brushless direct current motor with phase windings that are fed by an inverter connected to a voltage source having a high potential and a low potential. The semiconductor switches of the inverter are arranged in a bridge circuit and are controlled such that current always flows through two phase windings during motor operation. The motor is operated with normal commutation when the rotational speed is greater than or equal to a minimum rotational speed, wherein the angles are shifted by 60°. During start-up operation, up to the minimum rotational speed, a high-potential-side commutation angle of a phase winding is shifted toward a low-potential-side commutation angle of the phase winding by an angle greater than 0° and less than or equal to 60° with respect to the normal commutation.

Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.

Abstract: Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector.

Abstract: A rotary electric machine system includes: a stator that has multi-phase stator coils and that generates stator magnetomotive forces based on respective stator currents having different phases supplied to the multi-phase stator coils; a rotor on which rotor coils are wound such that magnetic poles are formed by rotor currents generated in response to the stator magnetomotive forces generated by the stator; a regulating unit that regulates a flow direction of each of the rotor currents to one direction to thereby regulate a polarity of each of the magnetic poles; and a control unit that controls currents supplied to the stator coils on the basis of a target torque. The control unit superimposes a pulse on the stator currents to adjust the ratio of each of the stator currents and each of the rotor currents so as to minimize a copper loss in the stator and the rotor.

Abstract: A method and system for a commutation control circuit are provided. The system includes an integrating voltage counter electrically coupled to an electrical power bus, wherein the integrating voltage counter is configured to integrate over time a voltage signal received from the power bus and to generate a trigger signal when the integrated voltage signal equals a predetermined count. The system also includes a plurality of transistor pairs configured to receive a trigger signal generated by the integrating voltage counter and electrically coupled to respective windings of a motor.

Abstract: Provided is an inverter control system and method for an eco-friendly vehicle, by which overall improvements can be obtained in terms of switching loss, electromagnetic performance, noise-vibration-harshness (NVH) performance, control stability, and so forth, when compared to a conventional case in which one fixed switching frequency and one fixed sampling frequency are used over the entire operation area. To this end, the inverter control method for an eco-friendly vehicle which generates a pulse width modulation (PWM) signal according to a switching frequency and a sampling frequency and controls ON/OFF driving of a switching element, in which a controller changes and sets the switching frequency according to a current motor speed, changes and sets a sampling frequency according to the switching frequency, and controls on/off driving of a switching element according to the switching frequency corresponding to the motor speed and the sampling frequency.

Abstract: A control device that drives one driven object by a first motor and a second motor. A first processor has a first correction amount calculation unit configured to calculate an amount of correction for a torque command to the first motor based on a speed value difference between a speed value of the first motor and a speed value of the second motor in order to suppress vibrations. A second processor has a second correction amount calculation unit configured to calculate an amount of correction for a torque command to the second motor based on a speed value difference between a speed value of the first motor and a speed value of the second motor in order to suppress vibrations.

Abstract: A ventilating system that can make an air flow rate variable includes a DC motor that drives blades and a control circuit that controls the DC motor. The control circuit includes a first current detecting unit that detects a current flowing in the DC motor, a rotating speed detecting unit that detects a rotating speed of the DC motor, and a control unit that controls the DC motor based on a rotating speed detected by the rotating speed detecting unit and a current detected by the first current detecting unit. The current detecting unit includes a plurality of low-resistance resistors, detects a motor current by using divided voltages of the low-resistance resistors, and calculates a ventilation air flow rate based on the rotating speed detected by the rotating speed detecting unit and the current detected by the first current detecting unit.

Abstract: In a driver, a discharging module discharges, at a discharging rate, the on-off control terminal of a switching element in response to a drive signal being shifted from an on state to an off state. A changing module determines whether a condition including a level of a sense signal being higher than a threshold level during the on state of the drive signal is met, and changes the discharging rate of the on-off control terminal in response to the drive signal being shifted from the off state to the on state upon determination that the condition is met. A loosening module loosens the condition after a lapse of a period since the shift of the drive signal from the off state to the on state in comparison to the condition immediately after the shift of the drive signal from the off state to the on state.

Abstract: A method of obtaining a maximum magnetic flux of a permanent magnet synchronous motor may comprise: receiving a first command voltage from a current controller to control current applied to the permanent magnet synchronous motor; receiving an on/off duty ratio of a control pulse signal to control an output voltage of an inverter that drives the permanent magnet synchronous motor, the on/off duty ratio being determined based on the first command voltage; generating a second command voltage corresponding to the output voltage to be output from the inverter based on the on/off duty ratio of the control pulse signal; obtaining a maximum command voltage error by comparing the first and second command voltages; and/or obtaining the maximum command magnetic flux of the permanent magnet synchronous motor according to a position of a rotor of the permanent magnet synchronous motor based on the maximum command voltage error.

Abstract: A motor control apparatus applying a sinusoidal drive waveform to a motor and including a position detection unit outputting a signal according to a motor shaft's position; and a control unit: acquiring a phase value of the motor's drive waveform when a signal is output by the position detection unit, changing a cycle of the drive waveform by measuring time from a previously output signal to a presently output signal, comparing the phases of the drive waveform and the motor shaft, and controlling to change to a cycle at which a phase value of the drive waveform matches a target phase value when a travel time corresponding to a phase value for adjustment has elapsed from a present time when a phase value of the drive waveform presently acquired differs from a target phase value acquired when the motor's drive current and drive voltage are in a designated phase relationship.

Abstract: An inverter for generating a plurality of alternating signals to be supplied to a motor, the motor having a plurality of phases and a plurality of coils arranged at each of the plurality of phases is provided. The inverter is a motor driving inverter characterized in including a multi-level pulse-density modulator configured to modulate a signal that fluctuates periodically and controls rotation of the motor; and a plurality of switching elements configured to generate each of the plurality of alternating signals by controlling an ON/OFF of a direct current according to selection by an output signal of the pulse-density modulator.

Abstract: A control device for an electric motor driving apparatus, configured with a switching control unit that performs rectangular wave control in which a plurality of switching elements provided in a direct current-alternating current conversion unit are ON/OFF-controlled to output rectangular wave-shaped voltages of a plurality of phases. System voltage varies during execution of the rectangular wave control, the switching control unit performs rectangular wave width adjustment control to set ON/OFF timings of the plurality of switching elements on the basis of a rate of change of the system voltage such that time-integrated values of the rectangular wave-shaped voltages of the respective phases within a control period set at a length corresponding to an integral multiple of a single electrical angle period are substantially identical among the respective phases.

Abstract: A method is described for controlling an electric machine during a motor startup operation with the aid of a power electronics device, in particular for use in a motor vehicle. The power electronics device includes a plurality of controllable power switches which are connected for the purpose of supplying an electrical current to the electric machine in polyphase form. The power electronics device is controlled in such a way that the electric machine outputs a startup torque, and the control of the power electronics device for outputting the startup torque takes place in such a way that the switching position of at least two of the power switches is changed, with the result that the power switches are subjected to a more uniform load.

Abstract: The present invention has an object to detect a three-phase AC motor current with high accuracy only with DC input current measuring means to a three-phase PWM inverter, and reduce resonance of a DC power supply by a ripple current in driving an AC motor with a DC current via a three-phase PWM inverter. A carrier wave Cry_e earlier than that of a V phase is used to sample a U phase and a carrier wave Cry_l always later than that of the V phase is used to sample a W phase. Thus, a sampling time sufficiently longer than an interval Ts of the carrier waves Cry_e, Cry_m and Cry_l can be ensured, and the current can be easily detected.

Abstract: Simple AC circuitry driving a brush-less motor having a rotor consisting of alternate polarity permanent magnet poles, with the rotor journaled in a stator with a like number of wound poles having only two free ends for energizing. The motor is using only two AC electronic switches for starting and accelerating, and an AC switch to run the motor at synchronous speed. It has higher efficiency than previously known circuits, uses less parts and is less costly.

Abstract: An energy converter includes a magnetism generation mechanism unit that generates a magnetic field when connected to an AC electrical power source, and a rotating mechanism unit having a single turn coil array member in which a plurality of single turn coils is disposed at a predetermined interval and a soft magnetic metal plate disposed on a side of the single turn coil array member opposite to the magnetism generation mechanism unit. The rotating mechanism unit is structured such that the single turn coil array member faces the magnetism generation mechanism unit across a predetermined magnetic gap and rotary driven by the magnetic field. Here, a drive signal period of the electrical power source is a period that maximizes an eddy current generated in the soft magnetic metal plate.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: An inverter controller controlling an inverter main circuit, the inverter controller including: a PWM signal generating part which generates a PWM signal to control on-off of a plurality of switching elements configuring the inverter main circuit; an operating state detecting part which detects an operating state of a load based on a direct current bus voltage of the inverter main circuit, a motor current which flows between the inverter main circuit and the load and an operation instruction to the load; a gate resistance selecting signal generating part which generates a gate resistance selecting signal corresponding to the operating state of the load; and a gate resistance selecting part which selects gate resistances connected to gate terminals of the switching elements of the inverter main circuit by using the gate resistance selecting signal.

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: A controller that controls a switching element of an inverter using pulse width modulation is applied to a power converter including an inverter, to realize a stable change of a carrier frequency, current control responsiveness, and inverter loss suppression. The controller includes a carrier-frequency setting unit that sets a carrier frequency command used for pulse width modulation of an inverter corresponding to a current command and a current-command change rate. The carrier-frequency setting unit includes a carrier frequency map having mapped thereon information of a carrier frequency corresponding to a current command expressed in a vertical axis and a current-command change rate expressed in a lateral axis, and outputs information of a carrier frequency on the carrier frequency map corresponding to the input current command and the input current-command change rate to a switching pattern calculator.

Abstract: When performing PWM control in accordance with an overmodulation mode, an ECU variably sets a switching determination value, which is used for determination of switching control modes between the overmodulation mode and a sinusoidal wave modulation mode, based on a switching state of an inverter at present. Then, the ECU compares the degree of modulation, which is calculated from voltage command values, with the switching determination value so as to determine whether to switch to the sinusoidal wave modulation mode or to maintain the overmodulation mode. In particular, when an influence of a dead time is likely to cause generation of a voltage command that requires switching to the overmodulation mode just after switching to the sinusoidal wave modulation mode, the switching determination value is variably set to prevent the transition from the overmodulation mode to the sinusoidal wave modulation mode. This prevents chattering in which the control modes are frequently switched therebetween.

Abstract: A motor controlling apparatus includes: a controller configured to (i) compute a target duty cycle value which is a target value for a duty cycle used for a pulse width modulation control for controlling a motor, and (ii) specify 100% as a duty cycle specified value when the target duty cycle value is greater than an upper limit value which is below 100%, or specify 0% as the duty cycle specified value when the target duty cycle value is less than a lower limit value which exceeds 0%; and a control signal generator that generates a control signal for controlling the motor at the duty cycle specified value specified by the controller.

Abstract: A power train for a transport vehicle is provided. The power train includes an electric motor comprising a shaft, a stator and a rotor, a power supply system receiving direct input voltage and delivering a polyphase voltage to the motor. The system has a modulation factor equal to the voltage amplitude of each phase of the motor divided by the direct input voltage, and includes a sensor for the rotational speed of the rotor.

Abstract: A control device for an electric motor driving apparatus, configured with a switching control unit that performs rectangular wave control in which a plurality of switching elements provided in a direct current-alternating current conversion unit are ON/OFF-controlled to output rectangular wave-shaped voltages of a plurality of phases. System voltage varies during execution of the rectangular wave control, the switching control unit performs rectangular wave width adjustment control to set ON/OFF timings of the plurality of switching elements on the basis of a rate of change of the system voltage such that time-integrated values of the rectangular wave-shaped voltages of the respective phases within a control period set at a length corresponding to an integral multiple of a single electrical angle period are substantially identical among the respective phases.