To provide a technology for suitably driving a brushless DC motor in a wide range of a speed zone.
This brushless DC motor system includes the brushless DC motor 5, an inverter 3, current sensors 6u, 6v and 6w that detect armature currents of the brushless DC motor 5, and control device 8 that generates a PWM signal SPWM in response to the armature currents. The inverter 3 drives the brushless DC motor 5 in response to the PWM signal SPWM. The control device 8 selects one of control method groups including sensorless vector control and V/f control as a selection control method is response to a speed command ω*. The control device 8 selects the sensorless vector control as the selection control method when the speed command ω* is in a first speed region ωs2-ωs3.
AIBA KENICHI
OTAKE HIROYUKI
ITO YASUMI
WATANABE TAKAMASA
Keisaku Nakao