Abstract: A power converter a controller that includes an instruction calculator calculating a first voltage instruction value that is applied to a first winding group, for example. An application voltage to the first winding group is controlled, for example, in a first period so that a first neutral point voltage shifts below a center-of-output value of an outputtable range is outputted, and a second neutral point voltage shifts above the center-of-output value of the outputtable range. The instruction calculator calculates the first instruction value for enabling a switching between the periods, after a lapse of a switch period that is variably calculated based on a preset physical quantity. In such manner, a ripple of a torque or an electric current accompanying the switching between the periods is reduced.

Abstract: A power converter that reduces a ripple of a torque and a ripple of an electric current in a switch period, having a controller including an instruction calculator that calculates a first voltage instruction value and a second voltage instruction value when, in a first period, a first neutral point voltage is shifted below a center-of-output value, and a second neutral point voltage is shifted above the center-of-output value, and, in a second period, the first neutral point voltage is shifted above the center-of-output value, and the second neutral point voltage is shifted below the center-of-output value.

Abstract: The purpose is to suppress ripple of voltage between terminals of smoothing condenser. Electric motor control apparatus is electric motor control apparatus that controls electric motor system having electrical power converter, smoothing condenser and three-phase AC electric motor, and has generating device that generates modulation signal by adding third harmonic signal to phase voltage command signal; controlling device that controls operation of electrical power converter by using modulation signal; and adjusting device that adjusts amplitude of third harmonic signal, adjusting device adjusts amplitude of third harmonic signal so that peak value of voltage between terminals of smoothing condenser in the case where amplitude of third harmonic signal is adjusted is smaller than peak value of voltage between terminals in the case where amplitude of third harmonic signal is not adjusted.

Abstract: An electric power tool includes a drive source, a rechargeable battery that supplies power to the drive source, a voltage meter that measures voltage of the rechargeable battery, a temperature meter that measures temperature of the rechargeable battery, and a drive control unit that regulates the power supplied to the drive source from the rechargeable battery to drive the drive source. If the battery temperature measured by the temperature meter is lower than or equal to a predetermined temperature when the battery voltage measured by the voltage meter is lower than or equal to a predetermined voltage, the drive control unit drives the drive source differently from normal driving that is performed if the battery temperature is higher than the predetermined temperature when the battery voltage is higher than the predetermined voltage.

Abstract: Controlling a multiphase electric motor by controlling the transmission of power to a first set of phases of a multiphase electric motor in accordance with a first operating configuration; detecting the presence of a shorted phase in the first set of phases while the first set of phases are being operated in accordance with the first operating configuration; and, responsive to detection of the shorted phase, adjusting control of the transmission of power to the multiphase electric motor such that power is transmitted to a second set of phases in accordance with a second operating configuration.

Abstract: When regenerative power from an AC motor via an inverter exceeds a predetermined power threshold, a charging/discharging control unit, which outputs a control signal for controlling the inverter on the basis of a DC bus voltage value and a charging/discharging current value, causes a power storage device to be charged such that the DC bus voltage value becomes a voltage threshold corresponding to the power threshold and causes a charging current at a start time of charging to the power storage device to start from a charging current value that is based on a DC bus voltage value.

Abstract: A DC electric fan receiving a first direct current voltage is provided. The DC electric fan includes a motor, a fan blade, a voltage converting device and a motor controller. The motor is directly driven by the first direct current voltage. The fan blade is connected to the motor and rotated by the driving of the motor. The voltage converting device receives and converts the first direct current voltages to a second direct current voltage, wherein the magnitude of the first direct current voltages is larger than the magnitude of the second direct current voltage. The motor controller receives the second direct current voltages to control a rotation direction of the motor, wherein the motor controller is not powered by the first direct current voltage and the first direct current voltage is a fixed direct current voltage.

Abstract: Provided is a rotating electrical machine capable of downsizing. The rotating electrical machine includes: a stator (2) including an armature winding (9); a rotor (3) provided inside the stator (2) in a rotatable manner; a power circuit unit (18) including a power circuit semiconductor switching element, for supplying a current to the armature winding (9); and a control board (6) in which an energization-allowed time corresponding to revolution speed of the rotor (3) is set, for controlling supply of the current by the power circuit unit (18), in which the control board (6) stops the supply of the current by the power circuit unit (18) when an integrated time of energization times to the armature winding (9) is longer than the energization-allowed time.

Abstract: A system and method for dynamically optimizing flux levels in electric motors based on estimated torque. Motor parameters and motor equations are used to estimate operating characteristics and to set current and voltage limits which define an optimal flux operating range for a given speed and torque of the motor. A slope of a linear flux gain is determined within the defined operating range at different speeds of the motor. The determined slopes for the different speeds are saved in a memory element. A control element determines and achieves an optimal flux level for the motor by accessing the table to identify a specific slope which corresponds to an actual speed of the motor, multiplying the slope by the estimated torque and adding an offset value to determine a phase current component value associated with the optimal flux level, and applying the determined phase current component value to the motor.

Abstract: In a control apparatus, an extractor extracts, from a rotational speed of a rotating member, a vibration component included in the rotational speed of the rotating member. A first suppressor performs first suppression to suppress the rotational speed of the rotating member from changing due to change of a speed change ratio. A mode setter switchably sets one of an enabling mode to enable the first suppression or a disabling mode to disable the first suppression in the control apparatus according to a parameter indicative of the speed change ratio. A second suppressor performs second suppression to suppress change of the vibration component generated based on switching of one of the enabling mode and the disabling mode to the other thereof.

Abstract: A method of controlling an ultrasonic motor coupled to a motor driver circuit, comprises receiving a temperature signal representing the temperature of the ultrasonic motor, receiving a position signal output by a first encoder representing the position of the ultrasonic motor, calculating an error between the position of the ultrasonic motor represented by the position signal and a target position, calculating a control signal based on the temperature of the ultrasonic motor represented by the temperature signal and the calculated error, and sending the control signal to the motor driver circuit to control the ultrasonic motor.

Abstract: A phase detector includes a crossing-point phase detection circuit to compare signals levels of pairs of sensor signals and output crossing-point phase detection signals indicating phases of crossing points between the pairs of the sensor signals, each having a signal level corresponding to a rotational position of a rotor of a motor having coils, a crossing-point level detection circuit to output crossing-point level signals indicating crossing-point levels detected, a signal selection circuit to select one of the sensor signals as a selection signal, a phase detection circuit to detect that a signal level of the selection signal has reached a threshold level, and output a phase data signal indicating a phase of the rotor corresponding to the threshold level, and an in-phase level adjustment circuit to adjust and output in-phase levels of the sensor signals to approach each of the crossing-point levels to a predetermined signal level.

Abstract: A motor control system which uses position command values output from control parts for motors and feedback information from axes which are driven by the command values for feedback control of the axes in an environment in which when one or more axes among axes which are driven by motors are driven, the other axes receive interference, which motor control system calculates acceleration of an axis which is driven by a motor by a first control part, sends the calculated acceleration to a second control part using a communication device, multiplies the acceleration which was input at the second control part with a compensation gain to calculate a position compensating value which compensates the position of an axis, adds the calculated position compensating value to the position command value of the axis, and uses the compensated position command value to control the position of the axis.

Abstract: A driving device of a multi-phase motor having a plurality of coils is provided. The driving device includes a back electromotive force (BEMF) detecting comparator connected to one of the plurality of coils to compare BEMF generated in one end of the one of the plurality of coils with a midpoint voltage of the plurality of coils and generate a BEMF detection signal, when the multi-phase motor starts to be driven; and an initial state detecting unit configured to detect a rotation state of the multi-phase motor based on the BEMF detection signal and a hall detection signal.

Abstract: The invention provides a motor driving apparatus of the invention comprises a power semiconductor device (11) for power conversion; a driving unit (12) controlling driving of the power semiconductor device (11) to supply power to a motor; a heat transmission structure (13) transferring a heat generated from the power semiconductor device (11) to a cooling medium via a heat conduction member; a temperature detection unit (14) detecting a real temperature of the heat conduction member; a current detection unit (15) detecting a current value of an output current from the power semiconductor device (11) to the motor; a temperature estimation unit (16) calculating an estimated temperature of the heat conduction member based on the output current value; and an abnormality detection unit (17) determining presence or absence of an abnormality in the heat transmission structure (13) based on a difference between the real and the estimated temperatures.

Abstract: An electric working machine including: a motor; a driving unit configured to be driven by the motor; a trigger switch configured to allow rotation of the motor; a power supply unit configured to supply electric power to the motor; and a control unit configured to control rotation of the motor, characterized in that: the electric working machine further comprises a switching element configured to perform short-circuiting between terminals of the motor to apply electronic braking, wherein the control unit is configured to perform adjustment of the braking by controlling the switching element when stopping the motor.

Abstract: An encoder that detects a position of a movable body from an origin includes a signal generation unit configured to generate an incremental signal and an origin candidate signal by using A-phase and B-phase voltages obtained from an orthogonal signal pattern, a reference position detection unit configured to detect a reference position signal by using a Z-phase voltage obtained from a reference position signal pattern, and a counter configured to reset a counted value of the incremental signal on the basis of the origin candidate signal.

Abstract: The motor controller includes: a current detection section that detects a current between a battery and an inverter circuit generating a voltage applied to a coil of a motor; an overload determination value output section that outputs an overload determination value used to determine whether or not the motor is overloaded; an overload determination section that compares a current value detected by the current detection section against the overload determination value, and that determines the motor to be overloaded in a case in which the current value detected by the current detection section is the overload determination value or greater; and a forced 500 rpm instruction section that controls the motor rotation speed to 500 rpm, this being a specific speed, in a case in which the overload determination section has determined the motor to be overloaded.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. A speed control module controls the drive circuit to rotate the motor at a requested speed. A speed determination module generates the requested speed based on a speed demand from a system controller. A lost rotor control module identifies a lost rotor condition and, in response to identifying the lost rotor condition, instructs the speed determination module to set the requested speed to an override speed that is lower than the speed demand. The lost rotor control module identifies the lost rotor condition in response to a comparison of a speed error with an adaptive threshold. The speed error is based on a difference between requested and estimated speeds of the motor. During first and second system states, the adaptive threshold is set to first and second thresholds, respectively.

Abstract: A motor driving device includes an analog to digital conversion circuit to which a speed command voltage instructing a rotation speed of a motor is inputted, and a microcomputer configured and programmed to generate a speed command having a pulse width which is changed according to the speed command voltage based on an output signal of the analog to digital conversion circuit. Further, the motor driving device includes a signal isolator configured to transmit the speed command between an input and an output while providing isolation between the input and the output, and a drive circuit configured to generate a driving signal in response to the speed command outputted from the signal isolator and to change the rotation speed of the motor.