| 摘要 |
A method of controlling a motor (9) includes the steps of a) acquiring a rotational speed parameter; b) selecting one of a three-phase modulation scheme and a two-phase modulation scheme as a switching signal generation system based on a result of comparing a rotational speed (S45) of the motor (9) with a predetermined reference speed; c) calculating phase voltage command values (S49) based on a target rotational speed (S40) and the rotational speed parameter; d) generating switching signals (S4) by employing the selected switching signal generation system based on the phase voltage command values (S49); and e) outputting the switching signals (S4) to an inverter (2). In step b), the two-phase modulation scheme is selected when the rotational speed (S45) of the motor (9) is higher than the reference speed. Thus, a switching loss can be reduced and power efficiency can be improved without deteriorating starting characteristics and motor drive characteristics when the rotational speed (S45) is low. |
