Abstract: In the work device that has a self-holding circuit (61) maintaining power supply from a power supply circuit (12) by output from a microcomputer (40) and has a structure in which stopping output to the self-holding circuit (61) causes interruption of power supply from the power supply circuit (12) to the microcomputer (40), the firmware of the microcomputer (40) is made to be rewritable and a power holding unit (condenser C1) for temporarily continuing power supply to the microcomputer (40) is provided, thereby realizing a so-called “off-delay timer function” for restarting the microcomputer (40). This configuration enables maintenance of power to the microcomputer (40) after update of the firmware even in a work device that cannot be restarted once power has been turned off unless trigger operation is performed, thereby enabling automatic restart of the microcomputer 40 after resetting is enabled.

Abstract: A vehicle control apparatus capable of protecting a pre-charge circuit is provided. When a voltage has entered an operating voltage range, a microcomputer determines whether a preset period has elapsed from then. Upon determining that the preset period has elapsed, the microcomputer starts initial check. To carry out the initial check, the microcomputer starts charging a capacitor for power supply stabilization of a drive circuit by turning on the pre-charge circuit and, when the charging of the capacitor is completed, turns on a power supply relay provided on a power supply line that connects between a battery and the drive circuit.

Abstract: A novel power inverter system for transferring electric power between a DC power source and a multi-phase electric machine is described, and includes a power inverter, a Z-source inverter, a first switch, and a second switch. The first switch is arranged between positive and negative conductors of a high-voltage bus that is electrically coupled to the DC power source, and the second switch is arranged in-line on the positive conductor of the high-voltage bus.

Abstract: A system includes a motor-driven component, a motor configured to operate the motor-driven component, and a motor drive circuit configured to power the motor. The motor drive circuit includes at least one complementary stage, where each stage includes a first transistor and a second transistor. During operation of the motor drive circuit, the first transistor is switched on when the second transistor is switched off. The system includes a controller communicatively coupled to the motor drive circuit. A load condition associated with the component is monitored. Based on the load condition, the controller determines whether the component is operating at a light load condition. If the component is operating at the light load condition, a switching frequency of each of stages is changed from a first switching frequency to a second switching frequency, which is less than the first switching frequency.

Abstract: A gate drive semiconductor device includes: external terminals to which PWM control signals are supplied; external terminals outputting a drive signal for driving a three-phase BLDC motor; external terminals to which the counter electromotive voltage generated by driving the three-phase BLDC motor is supplied; a zero-cross determination unit generating an interrupt signal indicating timing at which the counter electromotive voltage intersects with a midpoint potential of the three-phase BLDC motor based on the PWM control signal and the counter electromotive voltage; and an external terminal outputting the interrupt signal.

Abstract: A control circuit includes: a converter configured to convert alternating current (AC) power into direct current (DC) power, an inverter configured to generate driving power of at least one motor using the converted DC power, and a first core formed by winding a coil by a number of windings determined in correspondence with an impedance of the at least one motor. The number of windings is determined such that an impedance of the first core is inversely proportional to the impedance of the at least one motor and a driving power line for driving the at least one motor passes through a center of the first core.

Abstract: The power supply system includes: a first power circuit having a first battery, a second power circuit having a second battery, a voltage converter which converts voltages between both circuits, voltage sensors which acquire a first circuit voltage value V1 and second circuit voltage value V2, a current sensor which acquires a passing current value Iact, and a passing power control unit which operates the voltage converter. The passing power control unit performs PWM control under a control duty ratio obtained by summing a correction duty ratio calculated based on the current deviation change rate and a base duty ratio, in a case of, after starting PWM control under the base duty ratio decided based on the voltage values V1, V2 during activation of the voltage converter, the value of current deviation between a passing current value Iact and activation target value Itrg exceeding a permitted range.

Abstract: A motor drive device includes: a converter converting an AC voltage supplied from an AC power supply into a DC voltage; a smoothing capacitor smoothing the DC voltage output from the converter; an inverter converting the DC voltage smoothed by the smoothing capacitor into an AC voltage to drive a motor; a regenerative circuit that is disposed between the smoothing capacitor and the inverter, includes a first resistor and a first switch, and short-circuits the ends of the smoothing capacitor through the first resistor by turning on the first switch; and a control unit keeping the first switch in the OFF state during an emergency stop.

Abstract: The task of the present invention is to provide a driving circuit capable of outputting information useful to design or control of a system to outside. The present invention relates to a driving circuit and a driving method of a stepping motor, and an electronic machine using the driving circuit of a stepping motor. A counter electromotive force detection circuit detects a counter EMF generated in a coil. A revolution count detection circuit acquires the revolution count of the stepping motor. A load angle estimating portion calculates a load angle according to the counter EMF and the revolution count. An interface circuit is configured to be capable of outputting angle information associated with the load angle to outside, or accessing the angle information from the outside.

Abstract: An ECU includes a plurality of control circuits which is configured to control driving of a motor and communicate each other. The control circuits are configured to switch control modes including an ADS mode for controlling the driving of the motor based on a steering angle command ?s* and a torque control mode for controlling the driving of the motor based on a torque command value. A first control circuit, which calculates an EPS current command value shared by the plurality of control circuits in an EPS mode, and a second control circuit, which calculates an ADS current command value shared by the plurality of control units in an ADS mode, are different. This makes it possible to reduce a calculation load as compared with a case where the same control circuit serves as an EPS master and an ADS master.

Abstract: A drive control for a three-phase motor has an inverter with multiple switches for generating three-phase voltages on the windings of the three-phase motor, and a control device for controlling the switches of the inverter on the basis of pulse-width modulation. The control device is set up to control the switches in a switching period by using a switching pattern, wherein the switching pattern is composed of two active voltage space vectors and multiple null vectors, wherein the null vectors vary within the switching pattern.

Abstract: A battery pack and charger system includes a first battery pack having a first set of battery cells and configured to provide only a first operating voltage and a second battery pack having a second set of battery cells and configured to provide the first operating voltage and a second operating voltage that is different from the first operating voltage and a battery pack charger configured to be able to charge the first battery pack and the second battery pack.

Abstract: In a loaded condition, the controller increases at least one of the conduction band or the advance angle from a baseline value up to a maximum value within a first torque range below a torque threshold to as to maintain the output speed of the motor at a linear speed-torque profile. After the at least one of the conduction band or the advance angle reaches the maximum value, the controller maintains the at least one of the conduction band or the advance angle at the maximum value within a second torque range greater than or equal to the torque threshold so as to maintain the output speed of the motor at a naturally-curved speed-torque profile.

Abstract: A brushless DC motor system control method provided is based on a hybrid energy storage unit. The HESU topology is designed, and the output of the designed HESU is connected to the input of three-phase inverter, and the output of three-phase inverter is connected with the three-phase windings of the BLDCM. In braking operation, two kinds of braking vectors are constructed according to the HESU and three-phase inverter. Moreover, through the combined action of the two vectors, the braking torque control is achieved and meanwhile the braking energy is fed back to the supercapacitor. In electric operation, four kinds of electric vectors are constructed according to the HESU and three-phase inverter. Moreover, the power sharing control between battery and supercapacitor is realized by different vectors action during motor acceleration mode, and the torque ripple in commutation period is suppressed by different vectors action during motor constant speed mode.

Abstract: According to one embodiment, there is provided a control device including a determination unit, a correction unit and a drive controller. The determination unit determines whether a phase of a rotor of a stepping motor is ahead of or behind a target phase. The correction unit selects a correction value for a control value of a drive current of the stepping motor from among a plurality of correction values based on a determination result. The drive controller corrects the control value of the drive current with the selected correction value to drive the stepping motor.

Abstract: A motor control system for controlling operation of a motor having a plurality of windings includes a gate driver to provide a control signal to one or more switching elements controlling a voltage applied to the plurality of windings and a Field Oriented Control (FOC) controller configured to generate a PWM signal for coupling to the gate driver, wherein the FOC controller comprises a d-axis control loop configured to generate an applied d-axis voltage and a q-axis control loop configured to generate an applied q-axis voltage. A stall detector is configured to calculate an estimate of the q-axis voltage and compare the applied q-axis voltage to a threshold based on the estimate in order to detect a stall condition of the motor.

Abstract: Provided is a motor drive device including a motor having a rotor and a stator, an inverter electrically connected to the motor, and a control device for controlling the inverter. The control device includes: an impedance observer that estimates at least an amount of variation in impedance of the motor on the basis of a voltage command value, a current command value, and an actual current flowing between the inverter and the motor; a comparator that calculates a difference between the current command value and the actual current flowing between the inverter and the motor; and a failure detection unit that outputs a failure flag when the amount of variation in impedance exceeds or falls below a predetermined threshold, or when the difference calculated by the comparator exceeds or falls below a predetermined threshold.

Abstract: A control unit is configured to determine a first parameter from a back EMF signal, and to determine at least one second parameter from the back EMF signal corresponding to the first parameter. The control unit verifies, based on the first parameter, at least one condition containing the at least one second parameter, and detects stall or step-loss in the stepper motor based on the verification. The control unit uses a pattern detection by identifying characteristic features of peaks of the back EMF signal, which are order, magnitude and polarity. These characteristic features are independent of RPM, backlash, load and do not require complex calculations and are very robust even at lower RPMs.

Abstract: A method for controlling an electric motor is described herein. The method comprises setting a current limit, a speed limit and a torque limit. The method also comprises sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also comprises sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.

Abstract: A power tool is provided including a housing, a brushless motor disposed within the housing, a power switch circuit that supplies power from a power source to the brushless motor, and a controller configured to receive at least one signal associated with a phase current of the motor, detect an angular position of the rotor based on the phase current of the motor, and apply a drive signal to the power switch circuit to control a commutation of the motor based on the detected angular position of the rotor. If the supply of power to the motor is turned OFF to cause the motor to slow down and is turned back ON while the rotor speed exceeds a speed threshold, the controller electronically brakes the motor for a time interval to measure the phase current of the motor and detects the angular position of the rotor based on the measured phase current.