| 摘要 |
PURPOSE:To contrive to shorten a starting time, etc., while preventing overexcitation in a loom inverter for keeping the ratio of frequency to voltage constant by giving a torque boost in an operating range from starting to rated speed and by returning the ratio of frequency to voltage to a constant value at the time of reaching the rated speed. CONSTITUTION:The frequency command (f) of a frequency controller 6 is take in CPU 11, which compares the frequency command (f) and rated speed and conducts a torque boost until the command (f) reaches the rated speed. Therefore, the torque boost is given from starting to the rated speed to make a voltage higher at the time of acceleration to generate a high torque and to shorten a starting time from starting to the rated speed. After the rated speed is reached, the torque boost is cut so that a normal F/V constant control is returned and overexcitation is prevented. Also, if the torque boost is given when deceleration begins by generation of a temporary overload because the torque boost is given during acceleration, it is possible to reduce the decrease and variation of speed due to overload. |
