Abstract: A motor driving device includes: brushless DC motor (5) that drives a load that fluctuates during one rotation; and driver (9) that applies a voltage to brushless DC motor (5) and drives brushless DC motor (5). The motor driving device further includes speed accelerator (8) that determines the voltage to be applied by driver (9) so as to accelerate brushless DC motor (5) such that a speed change rate of a speed within one rotation from start of brushless DC motor (5) with respect to a speed at next one rotation remains within a predetermined value or less.

Abstract: A motor driving device includes: brushless DC motor (5) that drives a load that fluctuates during one rotation; and driver (9) that applies a voltage to brushless DC motor (5) and drives brushless DC motor (5). The motor driving device further includes speed accelerator (8) that determines the voltage to be applied by driver (9) so as to accelerate brushless DC motor (5) such that a speed change rate of a speed within one rotation from start of brushless DC motor (5) with respect to a speed at next one rotation remains within a predetermined value or less.

Abstract: Motor drive device (30) includes brushless DC motor (5) that drives a load and speed controller (8) that decides a PWM ON ratio for performing PWM control on brushless DC motor (5). The motor drive device further includes PWM ON ratio increasing-reducing unit (9) that increases/reduces the PWM ON ratio in accordance with a driving speed of brushless DC motor (5) and drive unit (10) that performs PWM control for driving brushless DC motor (5) in accordance with the PWM ON ratio decided by PWM ON ratio increasing-reducing unit (9). PWM ON ratio increasing-reducing unit (9) sets the PWM ON ratio to a ratio equal to or lower than the PWM ON ratio decided by speed controller (8) in an interval in which the driving speed of brushless DC motor (5) is lower than a predetermined speed, and sets the PWM ON ratio to a ratio equal to or higher than the PWM ON ratio decided by speed controller (8) in an interval in which the driving speed is higher than the predetermined speed.

Abstract: Phase correction unit (25) for outputting a commutation signal for switching a winding that allows a current to flow to brushless DC motor (4) and drive unit (16) for outputting a drive signal indicating supplying timing of electric power supplied to brushless DC motor (4) by inverter (3) based on the commutation signal output from phase correction unit (25) are provided so as to maintain a predetermined relation between a phase of a current flowing to a predetermined winding of brushless DC motor (4) and a phase of a voltage. Since brushless DC motor (4) is driven by a signal for holding the predetermined relation between the phase of the current and the phase of the voltage, the stability of drive under high-speed and high-load conditions is enhanced and a drive range is extended.

Abstract: To present a motor drive control device capable of realizing high speed driving by a simple power feeding control method. The motor drive control device of the invention has a three-phase full bridge circuit for adjusting the feeding phase so as to invert the terminal voltage in feeding-off time, by cyclically repeating positive direction feeding period, non-feeding period, negative direction feeding period, and non-feeding period. In high speed driving, the phase is adjusted so as to invert the terminal voltage right after feeding-off, and if not reaching the desired rotating speed, the feeding time is shortened. As a result, the phase angle to the actual applied voltage can be advanced, and high seed rotation by weak-field system driving is realized.

Abstract: Brushless DC motor (4) is driven based on a first or second waveform signal output from operation switching unit (11), which switches output so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thus, there is provided a motor driving device in which drive is stable even at high speed/under high load, and a driving range is extended.

Abstract: Brushless DC motor (4) is driven based on a first or second waveform signal output from switching determination unit (11), which switches outputting so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thereby, drive is stable even at high speed/under high load, and a driving range is extended.

Abstract: Phase correction unit (25) for outputting a commutation signal for switching a winding that allows a current to flow to brushless DC motor (4) and drive unit (16) for outputting a drive signal indicating supplying timing of electric power supplied to brushless DC motor (4) by inverter (3) based on the commutation signal output from phase correction unit (25) are provided so as to maintain a predetermined relation between a phase of a current flowing to a predetermined winding of brushless DC motor (4) and a phase of a voltage. Since brushless DC motor (4) is driven by a signal for holding the predetermined relation between the phase of the current and the phase of the voltage, the stability of drive under high-speed and high-load conditions is enhanced and a drive range is extended.

Abstract: To present a motor drive control device capable of realizing high speed driving by a simple power feeding control method. The motor drive control device of the invention has a three-phase full bridge circuit for adjusting the feeding phase so as to invert the terminal voltage in feeding-off time, by cyclically repeating positive direction feeding period, non-feeding period, negative direction feeding period, and non-feeding period. In high speed driving, the phase is adjusted so as to invert the terminal voltage right after feeding-off, and if not reaching the desired rotating speed, the feeding time is shortened. As a result, the phase angle to the actual applied voltage can be advanced, and high seed rotation by weak-field system driving is realized.

Abstract: A method of driving a brushless DC motor includes operations of rectifying an AC voltage of an AC power source by a rectifier circuit to which a capacitor is coupled between its output terminals and the AC voltage of the AC power source is input; driving the motor by an inverter coupled to the rectifier circuit; detecting a rotor position of the motor by a position detector based on a motor back electromotive force or a motor current; estimating the rotor position by a position estimator when the rotor position is not detectable by the position detector; and controlling the inverter by a controller based on the rotor position detected by the position detector or the rotor position estimated by the position estimator.

Abstract: A method of driving a brushless DC motor includes operations of rectifying an AC voltage of an AC power source by a rectifier circuit to which a capacitor is coupled between its output terminals and the AC voltage of the AC power source is input; driving the motor by an inverter coupled to the rectifier circuit; detecting a rotor position of the motor by a position detector based on a motor back electromotive force or a motor current; estimating the rotor position by a position estimator when the rotor position is not detectable by the position detector; and controlling the inverter by a controller based on the rotor position detected by the position detector or the rotor position estimated by the position estimator.

Abstract: A motor drive inverter control apparatus includes a rectifier circuit for rectifying an AC power supply, an inverter circuit driven by an output from the rectifier circuit, a motor driven by an output from the inverter circuit, a first capacitor coupled in parallel to the output of the rectifier circuit, and a second capacitor coupled in parallel to the first capacitor via a diode. The second capacitor has capacitance not less than three times that of the first capacitor. Although the second capacitor shows a ripple content not less than 90% during practical use, it well absorbs regenerative energy produced by the motor. As a result, elements of the apparatus can be prevented from degrading caused by an over-voltage, and the apparatus can be downsized and reduced its cost.

Abstract: A motor drive inverter control apparatus includes a rectifier circuit for rectifying an AC power supply, an inverter circuit driven by an output from the rectifier circuit, a motor driven by an output from the inverter circuit, a first capacitor coupled in parallel to the output of the rectifier circuit, and a second capacitor coupled in parallel to the first capacitor via a diode. The second capacitor has capacitance not less than three times that of the first capacitor. Although the second capacitor shows a ripple content not less than 90% during practical use, it well absorbs regenerative energy produced by the motor. As a result, elements of the apparatus can be prevented from degrading caused by an over-voltage, and the apparatus can be downsized and reduced its cost.