| 摘要 |
An inverter control device (6) provided with a stable control mode for rotationally driving a motor (5) at a rotation speed (Rn) selected from N-staged rotation speeds (R1 to RN), an acceleration control mode for increasing the rotation speed of the motor (5) to a target rotation speed (R(n+1)) which is one stage higher than the selected rotation speed (Rn), and a deceleration control mode for reducing the rotation speed of the motor (5) to a rotation speed (R(n-1)) which is two stages lower than the target rotation speed (R(n+1)) when the acceleration control mode is enabled. The inverter control device (6) shifts from the acceleration control mode to the deceleration control mode when, while the acceleration control mode is enabled, the amount of variation (&Dgr;V) of the output voltage (V) from a solar cell (1) exceeds a threshold voltage (VTH). It is thereby possible to reduce the power consumption of the motor (5), making it possible to prevent the motor (5) from stopping due to a power supply shortage. |
