In torque pulsation suppressing control in apparatus using battery as main power source, with feedforward table, there arises compensating table error due to voltage fluctuation by battery internal resistance, depending on load power. In system where compensating values for suppressing torque pulsation are collected beforehand in the form of compensating table, and the torque pulsation of each frequency component is suppressed by the torque compensating quantity determined by inputting torque command and sensed rotational speed, the system senses main power source voltage of controlled object, and to perform compensation by outputting the torque compensating quantity dependent on the voltage by inputting into the compensating table corresponding to voltage. Furthermore, a compensation correcting section corrects torque compensating quantity Tcn determined by the sum of output Ta of real part compensating table and quantity jTb of imaginary part compensating table, with predetermined table or proportional expression depending only on voltage.

An AC-DC photovoltaic device is provided, including: a photovoltaic module, a direct current side capacitor, a DC-PWM power switching circuit and a controller. The direct current side capacitor is connected in parallel with an output terminal of the photovoltaic module. An input terminal of the DC-PWM power switching circuit is connected with the output terminal of the photovoltaic module. The DC-PWM power switching circuit includes a controllable switch transistor. The controller is configured to output a switch control signal to control a switching state of the controllable switch transistor in the DC-PWM power switching circuit, to control the DC-PWM power switching circuit to output a direct current PWM wave in a case that the switch control signal is a direct current modulation signal, and output an alternating current PWM wave in a case that the switch control signal is an alternating current modulation signal.

An AC-DC photovoltaic device is provided, including: a photovoltaic module, a direct current side capacitor, a DC-PWM power switching circuit and a controller. The direct current side capacitor is connected in parallel with an output terminal of the photovoltaic module. An input terminal of the DC-PWM power switching circuit is connected with the output terminal of the photovoltaic module. The DC-PWM power switching circuit includes a controllable switch transistor. The controller is configured to output a switch control signal to control a switching state of the controllable switch transistor in the DC-PWM power switching circuit, to control the DC-PWM power switching circuit to output a direct current PWM wave in a case that the switch control signal is a direct current modulation signal, and output an alternating current PWM wave in a case that the switch control signal is an alternating current modulation signal.

A motor control circuit with power factor correction capabilities that optimizes the voltage and current load applied to an electric motor for different motor speeds and torque levels. The preferred motor control circuit includes a power factor correction circuit and a step down conversion circuit through which current passes before it reaches the motor. A microprocessor preferably monitors the current supplied to the motor and the motor's speed. If the microprocessor determines that the current supplied to the motor is too high, it can reduce the level of current by either using a pulse width modulation (PWM) digital-to-analog control circuit to instruct the power factor correction circuit to reduce current or it can use a PWM digital control circuit to instruct the step down conversion circuit to reduce current. An output voltage limiter circuit can be used to detect the voltage of current supplied to the motor and turn off current to the motor if the voltage is above a predetermined level.

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The drive system includes an actuation member. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system includes an H-bridge circuit electrically couplable to the electric motor. The control system is configured to control the electric motor based on a sensed parameter associated with the electric motor, a position of the actuation member and a velocity of the actuation member.

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The drive system includes an actuation member. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system includes an H-bridge circuit electrically couplable to the electric motor. The control system is configured to control the electric motor based on a sensed parameter associated with the electric motor, a position of the actuation member and a velocity of the actuation member.

A method for determining a movement of a rotor of an electric motor, comprises supplying a drive signal to a drive coil of the electric motor, sensing a coil current of the drive coil, detecting current ripples of the sensed coil current caused by the rotor of the electric motor crossing ripple generating positions, inferring the movement of the rotor from the detected ripples, braking the motor by reducing the drive signal supplied to the drive coil from an initial signal value to zero according to a braking curve specifying a non-zero fall time during which the drive signal is reduced from the initial signal value to zero. The braking curve is adapted so that the rotor does not cross a ripple generating position after the drive signal has been reduced to zero.

A fan control circuit with temperature compensation includes an on-off unit and a speed adjustment unit. When determining that a loading is greater than or equal to an adjustable start threshold according to a load signal, the on-off unit controls the fan entering a working mode. In the working mode and determining that the loading is less than a speed-adjusting threshold, the on-off unit maintains a speed value of the fan at a first fixed speed. When determining the loading is greater than or equal to the speed-adjusting threshold, the speed adjustment unit adjusts the speed value according to the loading. The speed adjustment unit generates a speed displacement according to a temperature signal to compensate the speed value.

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.

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.