Abstract: A permanent magnet synchronous machine (PMSM) includes a stator and rotor powered by an inverter. A device to control the PMSM includes a sensor to sample a measurement ?m of the position of the rotor, a control unit to control an operating point of the PMSM according to the position of the rotor and settings, and an estimation unit to determine an estimate {circumflex over (?)} of the rotor position. The device also includes a malfunction detector to detect a malfunction of the sensor and a switch to connect the control unit to the sensor so that the control unit receives the measured position ?m of the rotor while the malfunction detector does not indicate any sensor malfunction, and otherwise to connect the control unit to the estimation unit so that the control unit receives the estimated position {circumflex over (?)} of the rotor when the malfunction detector indicates a sensor malfunction.

Abstract: In a method for operating a drive unit having an electric machine, in a normal operating mode the electric machine is operated with current provided by an inverter on at least two phases, and particular phase voltages for the electric machine are set on the phases. Upon an occurrence of an error of the inverter, the inverter is operated in an emergency operating mode for the further operation of the electric machine.

Abstract: An apparatus for controlling a wheel motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the wheel motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the wheel motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Abstract: A motor control apparatus including a motor control unit and a signal output unit that outputs a signal corresponding to rotation of the motor to displace an object to be driven to a target stop position, the motor control unit includes: a first control unit that estimates a current upper limit and determines a first control input; a second control unit that determines a second control input and controls the motor to stop the object to be driven at the target stop position; a first calculation unit calculates a necessary amount for stop, a second calculation unit that calculates a remaining displacement amount, a switching unit, enable the first control unit or the second control unit to control the motor with switching; based on the necessary amount for stop and the remaining displacement amount.

Abstract: A control unit for a rotary electric machine control system includes a first current command module, a second current command module and a change module. The first current command module controls the rotary electric machine based on a maximum efficiency characteristic line. The second current command module controls the rotary electric machine based on an early switching characteristic line, which is set at a retard angle side relative to the maximum efficiency characteristic line with a predetermined phase difference. When a control mode is switched over to a rectangular wave voltage phase control mode from an overmodulation current control mode in accordance with an increase in torque, the change module changes the current command from the first current command module to the second command current module.

Abstract: Control mode switching determination is made as a part of a main loop (control period for overall control of an AC electric motor. When switching from the rectangular wave voltage control mode to PWM control mode is determined, the change in voltage phase of the rectangular wave voltage is inhibited from the timing of control mode switching determination until the next execution of the main loop until the timing at which the control mode is actually switched, to maintain voltage phase of the rectangular wave voltage at the time of control mode switching determination. Consequently, in a drive controller for an AC electric motor allowing switching between control modes, control mode can appropriately be switched without destabilizing the operation of the AC electric motor.

Abstract: A control unit for a rotary electric machine includes a first current command module, a second current command module, a change module, and a return module. The first module performs a first current command on a maximum efficiency characteristic line on a d-q plane thereby to drive the machine at a maximum efficiency. The second module performs a second current command on a switching line set at a retard angle side relative to the maximum efficiency characteristic line. The change module changes a control mode from a rectangular wave voltage phase control mode to an overmodulation current control mode when an operation point of the machine reaches the switching line. The return module returns the current command from the second command to the first command after performance of the second command for a predetermined period.

Abstract: A motor controller is provided with a first PWM circuit that repeatedly outputs an on-signal at a first carrier frequency, a second PWM circuit that repeatedly outputs an on-signal at a second carrier frequency that is lower than the first carrier frequency, an AND circuit that receives both the on-signal outputted from the first PWM circuit and the on-signal outputted from the second PWM circuit and outputs a third on-signal which is a logical product of the received on-signals, and a voltage apply circuit that applies a voltage to the motor intermittently in synchronization with the third on-signal outputted from the AND circuit. At least one of the first carrier frequency and the second carrier frequency is equal to or lower than 1 kHz or equal to or higher than 3 kHz. As a result, generation of an unpleasant noise by a motor controller using two PWM circuits may be suppressed.

Abstract: A control unit of a rotary electric machine control system includes a stationary switching module and a transitional switching module. The stationary switching module switches over a control mode from a rectangular wave voltage phase control mode to an overmodulation current control mode by using a current phase of a smoothed current produced by filtering of high harmonic components on an actual current in a stationary operation state. The transitional switching module switches the control mode from the rectangular wave voltage phase control mode to the overmodulation current control mode by using the current phase of the actual current in a transitional operation state. The control mode is switched over by comparing the current phase of the actual current with a transitional switching reference line, which is preset separately from a switching reference line used for comparison with a current phase of the smoothed current.

Abstract: A motor starting apparatus includes a driving signal generating unit that generates an open-loop driving signal and a drive circuit that is connected to a motor. The driving signal generating unit includes a data storing unit that stores therein predetermined data, a velocity integrating unit that integrates velocity data, a phase adjusting signal generating unit that generates a phase adjusting signal, a three-phase driving signal generating unit that generates a three-phase applied voltage, and a drive circuit driving unit that generates a driving signal of the motor. The three-phase driving signal generating unit performs open-loop driving by outputting the three-phase applied voltage based on the phase adjusting signal to the drive circuit driving unit.

Abstract: A control apparatus for an AC motor controls an inverter in a pulse width modulation scheme to feed a coil current to a stator coil of a stator. A pattern switching mechanism switches a control pattern to a first pattern or to a second pattern; a first pattern calculating mechanism calculates a control signal using a first pattern parameter; a second pattern calculating mechanism calculates a control signal using a second pattern parameter; an offset calculating mechanism calculates a difference between a control signal of an old pattern and a control signal of a new pattern, and reflects the offset amount on the control signals; and a control output mechanism calculates a final control output signal on the basis of the control signals, and transmits the final control output signal to the inverter.

Abstract: A voltage application unit applies voltage to windings of a motor without passing though an inverter unit. A first detection unit detects a short circuit failure in switching elements of the inverter unit based on a terminal voltage between each of the switching elements and a corresponding winding and a power voltage of a power supply. Before rotation of the motor, when no short circuit failure is detected and when a switching unit switches at least one of the high and low potential-side switching elements of the inverter unit on and subsequently switches all the switching elements off, a second failure detection unit determines whether the switching unit is incapable of rendering the switching element non-conductive based on the terminal voltage and the power voltage.

Abstract: This invention provides an advanced position and velocity estimation scheme used in a position-sensorless control system for synchronous operation of an electric motor. The system includes an electric motor having a stator and a rotor; an inverter for powering the electric motor; and a controller for controlling the inverter. The controller utilizes a control system comprising a rotor angle and angular velocity estimation block; an estimated angle error detector block; a field-weakening block; and a torque-to-current converter block, all of which operate to generate control commands for operation of the motor.

Abstract: A method of calculating a control parameter for a component in an HVAC system includes receiving a plurality of input signals, and calculating a value of the control parameter using a control parameter equation having a plurality of predetermined coefficients and a plurality of variables, each variable corresponding to one of the input signals. This equation is stored in and subsequently fetched from memory associated with a component of the HVAC system, such as a blower motor controller or a system controller. In some embodiments, the equation is stored in a device for interfacing a system controller with a blower motor assembly.

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: The invention provides a driving circuit for a voice coil motor. In one embodiment, the driving circuit includes a logic circuit, a digital-to-analog converter, and an output circuit. The logic circuit generates a series of samples of a digital output signal according to a digital input signal, wherein the samples of the digital output signal sequentially alter from a first input value of the digital input value to a second input value of the digital input signal according to an alteration pattern determined by a mode selection signal. The digital-to-analog converter converts the digital output signal to an analog output signal. The output circuit generates a driving current signal according to the analog output signal for driving the voice coil motor.

Abstract: A DC motor control device calculates motor speed using determinations of motor field flux and armature voltage in the motor. The device includes a control module having one or more control inputs and one or more control outputs. At least one control input is configured to receive data representing field current measured in the DC motor. The control module includes flux curve logic that is responsive to measurements of motor field current to calculate a field flux in the motor. The flux curve logic uses a flux curve stored in the control module, the flux curve representing a functional relationship between field current and field flux in the motor. The flux curve is defined by a plurality of flux curve data points corresponding to a plurality of motor field currents within a lower current range and within an upper current range. The flux curve is further defined by at least a first flux curve line positioned within the lower current range and a second flux curve line positioned within the upper current range.

Abstract: A control device has a unit for determining a controlled phase of a controlled voltage outputted from an inverter to a generator according to a difference between a target torque and an estimated torque of the generator, a unit for calculating an instructed vector norm of the controlled voltage from the target torque, an electrical angular speed of the generator and parameters indicating characteristics of the generator, a unit for correcting the instructed norm to an adjusted vector norm such that a phase of current flowing through the generator in response to the controlled voltage set at the controlled phase and the adjusted norm is controlled to a phase of an instructed current determined from the target torque, and a unit for controlling the generator by controlling the inverter to output the controlled voltage set at the controlled phase and the adjusted norm to the generator.

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: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

Abstract: An electric motor protection system for protecting an electric motor of a household appliance includes a temperature sensor for sensing a temperature of the electric motor, a motor speed sensor for sensing a speed of the electric motor, a current sensing circuit for sensing an electric current supplied to the electric motor, a power control device for controlling the electrical power supplied to the electric motor, and a signal processing unit electrically connected to the temperature sensor, the motor speed sensor, the current sensing circuit, and the power control device. The signal processing unit is configured to make calculations and judgments based on the measurements of the temperature sensor, the motor speed sensor and the current sensing circuit, and a plurality of predetermined values, and to control the power control device accordingly so as to protect the motor from overheating, being overloaded, or driven by excessive current.

Abstract: A method for controlling a traction power inverter module (TPIM) in a vehicle includes determining a commanded output torque of the motor using a controller. The method further includes controlling the TPIM and motor using a discontinuous pulse width modulated (DPWM) signal when the commanded output torque is less than a calibrated torque threshold. A continuous pulse width modulated (CPWM) signal is used when the commanded output torque is greater than the threshold. The method may include determining a direction of a change in the commanded output torque, and controlling the TPIM, via the controller, using the DPWM signal only when the commanded output torque drops below a predetermined hysteresis level. A vehicle includes a traction motor producing a motor torque for propelling the vehicle, an ESS, a TPIM, and a controller configured as noted above.

Abstract: To provide a motor control apparatus that uses an inverter to drive an AC motor and hybrid automotive control apparatus adapted to drive an AC motor by use of an inverter while reducing torque pulsations during switching from PWM driving to rectangular-wave driving. The motor control apparatus 100 has a PWM driving mode in which to input a PWM signal to the inverter 8 and perform PWM driving of the AC motor 4, and a rectangular-wave driving mode in which to input a rectangular-wave signal to the inverter 8 and perform rectangular-wave driving of the AC motor 4. For switching from the PWM driving mode to the rectangular-wave driving mode, a driving-pulse switching block 140 performs the switching process within a maximum pulse-width range of high-level or low-level pulses developed in the PWM driving mode.

Abstract: An electrical system comprising an electrical motor and a method for controlling the electrical motor. The system comprises the electrical motor, a power source connection, a first motor control device placed between the power source connection and the motor, and a second motor control device placed in parallel with the first motor control device, the first motor control device supplying electrical power to the motor at least one first operating condition of the motor, and the second motor control device supplying electrical power to the motor at least one second operating condition of the motor, wherein the at least one first operating condition differs from the at least one second operating condition of the motor.

Abstract: A pump control device for a pump device having a DC brushless motor as a drive source and a flow rate of the pump device is increased and decreased depending on a corresponding increase and decrease of a rotational speed of the DC brushless motor is structured so that, when the rotational speed of the DC brushless motor is higher than a predetermined speed, the DC brushless motor is controlled in an open loop control and, when the rotational speed of the DC brushless motor is lower than the predetermined speed, the DC brushless motor is controlled in a closed loop control on the basis of a measurement result of an actual rotating speed which is an actual rotational speed of the DC brushless motor.

Abstract: A phase current estimation device of a motor includes: an inverter which uses a pulse width modulation signal to sequentially commutate an electric flow to a motor of a three-phase alternating current; a pulse width modulation signal generation unit generating the pulse width modulation signal from a carrier signal; a control unit performing a startup control and a self control of the motor using the inverter; a direct current sensor detecting a direct current of the inverter; and a phase current estimation unit estimating a phase current based on the direct current detected by the direct current sensor.

Abstract: In order to enable in a motor system, in which a soft start of the motor has been implemented, the operation of the motor, wherein the power consumption is reduced, it is proposed to operate the driver circuit during a switch-on phase in order to carry out a soft start of the motor. In at least one embodiment, the driver circuit can be bypassed in a normal operational phase as a function of a load, by means of which the motor is operated.

Abstract: A control device for a driving apparatus. The control device is configured with a device that controls the rotary electric machine via the inverter, a device that determines whether a disconnect condition of the main power supply is satisfied, and a device that obtains an estimated field amount that is an estimated value of the field flux supplied from the rotor to the stator. The control device is also configured with a device calculates an induced voltage that is induced in the coil, and a device that determines whether an overvoltage state in which the induced voltage exceeds a voltage resistance of the inverter exists. If it is determined that an overvoltage state exists when the disconnect condition is satisfied, connection with a main power supply is maintained until the overvoltage state is eliminated. The rotary electric machine is controlled by weakening the field flux to the coil.

Abstract: The present invention relates to a motor that acts both as a synchronous motor and as an induction motor, and that comprises a stator (100) having coil windings, a rotor (200), where said rotor is a rotor with magnets (300, 310, 320, 330) generating 4 poles, and the windings of the stator (100) can be switched so as to change the number of poles. The subject motor acts as a synchronous motor when in low rotation and as an induction motor when in high rotation. During its operation as an induction motor, rotors (200) are utilized having a protuberance ratio near 1, generating a sufficient flux to reach good efficiency levels with 2 poles, which prevents the motor from having torque oscillations during its operation, providing a motor with a lighter operation and a better performance and less noise.

Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: A phase current estimation apparatus for a motor capable of suitably improving estimation accuracy of phase currents is provided. The phase current estimation apparatus 10 of the motor includes a control unit 24 that decomposes a command voltage vector Vdq into two vector components V?dq in the case where a magnitude of the command voltage vector Vdq is less than a predetermined lower limit voltage Vlow, so that the command voltage vector Vdq is allowed to have the magnitude equal to or more than the predetermined lower limit voltage Vlow for every two adjacent periods in units of a period of a carrier signal and to have the phase outside a predetermined phase range including phases of reference voltage vectors. Accordingly, the control unit 24 can quantitatively analyze harmonic components, which are generated by decomposing the command voltage vector Vdq into the two vector components V?dq, by using mathematical equations.

Abstract: A motor control system for heating, ventilation, and air conditioning (HVAC) applications is described. The motor control system includes a thermostat and an electronically commutated motor (ECM) coupled to the thermostat. The ECM is configured to retrofit an existing non-ECM electric motor included in an HVAC application and to operate in one of a plurality of HVAC modes. The HVAC modes include at least one of a heating mode, a cooling mode, and a continuous fan mode. The HVAC mode is determined based at least partially on outputs provided by the thermostat.

Abstract: An embodiment of a disk drive power system is described. The system is operable such that during power interruption, the system taps electric power by rectifying the back-EMF generated across each winding of a DC motor and supplying power to a voice-coil motor to park a read/write head safely away from an associated magnetic disk surface.

Abstract: A method for operating an electric machine with a driver system is provided, in which an operating variable of the electric machine and/or of the driver system is monitored. The validity of the input variables is checked with regard to their checksum and whether the input variables are up-to-date, and the permissibility of an actual moment (Mist2) of the electric machine depending on the operating state of the electric machine is checked. In case of invalid input variables or invalidity of the actual moment (Mist2), a fault reaction is initiated. In addition, the implementability of the planned change of rotary speed is checked and, in case of non-implementability, changed over into a more favorable mode of operation of the electric machine. An electric machine used as a starter/generator in a motor vehicle can be monitored.

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 triphase rotating electric machine includes three coils evenly distributed around a rotational axes of the machine, and at least one first sensor, capable of generating a periodic signal to represent the position of the machine around the axle and a control circuit capable of controlling, when in the first mode, the conduction of a switch (KUH), linked to at least one of the three coils based on the periodic signal generated by the first sensor (U), such that the conduction phases of the switch (KUH) have a duration in the order of half the signal period (U). The control circuit is capable of controlling switch (KUH), based on a second mode in which the conduction phases of the switch (KUH) have a duration in the order of a third of the signal period (U).

Abstract: A control device that controls for an electric motor drive device including a DC/AC conversion section that converts a DC voltage into an AC voltage to supply the AC voltage to an AC electric motor. The control device is configured with a computation cycle setting section that sets a computation cycle of the control signal generation section to a first cycle, which is N times (N is an integer of 1 or more) a reference computation cycle that is set to half a carrier cycle, and that sets a computation cycle of the voltage command value determination section to a second cycle, which is M times (M is an integer of 2 or more) the first cycle, in the case where the control mode determined by the control mode determination section is the pulse width modulation control mode.

Abstract: When a target operation point of either a motor MG1 or a motor MG2 is included in a resonance range specified by operation points of the motor MG1 or the motor MG2 in the occurrence of resonance in a booster converter, a hybrid vehicle controls the booster converter to make the voltage on the side of inverters approach to a preset target boosted voltage that is higher than the voltage on the side of the battery, while controlling the inverters by sine-wave control.

Abstract: The disclosed invention achieves a significant reduction in the noise and vibration of a brushless motor from a startup up to the number of steady revolutions. To drive the brushless motor from stop up to the number of steady revolutions, when the arithmetic sequencer detects a rise of a clock signal CARYCLK, current control arithmetic is executed. On detecting a fall of the clock signal, the arithmetic sequence determines whether a division control signal DIVCNT has changed. If this signal has changed, soft switch arithmetic is executed. When the division control signal has not changed or after the completion of soft switching arithmetic, the arithmetic sequencer determines whether a rise of a mask signal MASK has occurred during one cycle of the PWM carrier signal CARYCLK. If a rise of the mask signal has not occurred, the operation returns to the first step. If a rise of the mask signal has occurred, PLL control arithmetic is executed, then the operation returns to the first step.

Abstract: An electrical machine having a stator and a rotor. The stator includes a core and a plurality of windings disposed on the core in a multiple-phase arrangement. The rotor is disposed adjacent to the stator to interact with the stator. A method of operating the motor includes applying a pulsed voltage differential to first and second terminals of the windings resulting in movement of the rotor; monitoring the back electromotive force (BEMF) of the windings to sense rotor movement; after the applying and monitoring steps, monitoring the BEMF of the windings to determine whether the rotor is rotating in a desired direction, and electrically commutating the motor when the rotor is rotating in the desired direction and zero or more other conditions exist.

Abstract: A sensorless motor drive device has: a first operation mode of generating current waveforms including non-energizing times based on a first rotor position signal generated by detecting zero crossings in windings of a motor as a signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms; and a second operation mode of generating current waveforms including no non-energizing time based on a second rotor position signal generated without use of zero crossings as the signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms. The first and second operation modes can be switched to each other.

Abstract: The subject matter disclosed herein describes a system for controlling torque in a soft starter. In particular, torque ripple is reduced when transitioning between two different operating modes of a soft starter. A soft starter may include a first operating mode, designed for improved performance during low-speed operation of a motor, and a second operating mode, designed for improved performance during high-speed operation of the motor. However, transitioning between two different operating modes may result in significant transient currents in the motor, which, in turn, produce torque in the motor. The system described herein reduces this transient torque production in the motor.

Abstract: An energization control circuit compares a target rotation direction of a motor and an actual rotation direction of a motor detected based on rotation detection sensors. If the compared rotation directions are in disagreement, the energization control circuit switches over an inverter control mode from 120-degree energization to 180-degree energization to extend an on-period of a high-side switching element of an inverter circuit to an advance phase side. Thus, the high-side switching element is turned on, when a low-side switching element of the same phase is in a turned-off state. A free-wheeling current is allowed to flow through the high-side switching element rather than through a free-wheeling diode of the high-side switching element.

Abstract: In an apparatus, a first drive unit drives, in a first range of a voltage utilization factor, a switching member to thereby control an output voltage of the power converter to be matched with a command voltage. A second drive unit drives, in a second range of the voltage utilization factor, the switching member to thereby generate a value of a controlled variable of a rotary machine. The second range of the voltage utilization factor is higher than the first range thereof. An estimating unit estimates, during the switching member being driven by the second drive unit, a value of a parameter associated with the output voltage of the power converter. The estimated value is required for the first drive unit to generate the value of the controlled variable generated by the second drive unit.

Abstract: Circuitry for controlling motors, such as a brushless motor (BLM), is disclosed. The circuitry may comprise one or more inputs for receiving rotor position signals from one or more Hall effect sensors that detect the position of, for example, a BLM rotor. The circuitry may also comprise an input for receiving a pulse width modulated speed control signal. The circuitry generates one or more drive signals, each of which may comprise a logical combination (e.g., a logical AND combination) of the speed control signal and a rotor position signal, for controlling power switches that are coupled to electromagnets of the BLM.

Abstract: Switching elements are driven by a control signal outputted from a control circuit, so that a rotating magnetic field is generated from a stator coil to rotate a rotor of a synchronous electric motor. The control signal is generated through use of a selected modulation scheme, which is selected from a plurality of modulation schemes. The control circuit determines which one of the modulation schemes is used as the selected modulation scheme based on a sensed voltage value of a voltage sensor, which senses an output voltage of a power supply device.

Abstract: Disclosed is a control device capable of ending strong field control based on a voltage index, such as a modulation factor. A voltage waveform control unit performs PWM control when a voltage index indicating the magnitude of voltage command values with respect to a DC voltage is less than a predetermined square wave threshold value, and performs square wave control when the voltage index is equal to or greater than the threshold. A field adjusting unit performs strong field control on the condition that the voltage index is equal to or greater than a predetermined strong field threshold value less than the square wave threshold value. A mode control unit ends the strong field control when a rotational speed is less than a rotational speed threshold value determined on the basis of a target torque and the DC voltage.

Abstract: Disclosed is a control device capable of ending strong field control in a structure that performs strong field control and square wave control on the basis of a voltage index, such as a modulation factor. A voltage waveform control unit performs PWM control when a voltage index is less than a threshold, and performs square wave control when the voltage index is equal to or greater than the threshold value. A field adjusting unit performs strong field control when the voltage index is equal to or greater than a predetermined strong field threshold value less than the square wave threshold value. A mode control unit ends the strong field control when a field adjustment command value is equal to or greater than an adjustment command threshold value determined on the basis of a target torque and a voltage/speed ratio in a direction in which field flux is strengthened.

Abstract: A DC to three-phase AC inverter system includes a three-phase motor, an inverter circuit, switching elements, a capacitor, a DC power source and a control circuit. The DC power source is connected to the three-phase motor at a neutral point thereof. The control circuit calculates voltage commands, first through third divided boost commands by dividing a boost command, and first through third drive signals based on the voltage commands and the first through third divided boost commands. The second and third divided boost commands are used when the PWM control is performed by turning on and off the switching elements for the second and third phases while the switching elements for the first phase continues to be on or off state is set larger than those used when the PWM control is performed by turning on and off the switching elements for the first through third phases.

Abstract: In a back electromotive force phase detecting device, a timing generating unit generates a timing signal indicating a start timing, an intermediate timing and an end timing of a 180-degree electrical angle period in a detection target phase, from an excitation pulse signal. A difference calculating unit receives the timing signal, and calculates a difference between a total PWM control period of the detection target phase during a first-half 90-degree period, and a total PWM control period of the detection target phase during a second-half 90-degree period. In an excitation control device, a control unit changes the capability of driving a motor based on an output of the back electromotive force phase detecting device.