| abstract |
PROBLEM TO BE SOLVED: To perform a field weakening control of a brushless motor stably without using a control amount such as a preset table value and independently of an input voltage of an inverter circuit 3 in a motor driving device for driving a brushless motor. . SOLUTION: An inverter circuit 3 for converting an output voltage of a voltage source 1 into a three-phase alternating current and outputting the converted voltage to a motor 2, a rotor position estimating unit 5 for estimating a rotor position of the brushless motor, and an estimated rotor position And an inverter control unit 4a for controlling the inverter circuit 3 so that the brushless motor is driven by a current based on the current value supplied to the brushless motor. Is determined so that the deviation between the commanded rotational speed fo and the actual rotational speed f is minimized. [Selection diagram] Fig. 1 |