| 摘要 |
Proposed is an automatic adjustment method capable of appropriately setting a switching threshold value of a conducting phase as a sensorless method for detecting the rotor position of an AC electric motor on the basis of the voltage induced in a non-conducting phase and achieving a stable drive from a stop/low-speed region. To solve the above problem, an AC electric motor control device selects and conducts two phases of a three-phase AC electric motor, switches conducting phases on the basis of the comparison between the voltage value of the remaining non-conducting phase and a threshold value for said voltage value, and rotationally drives the three-phase AC electric motor. For setting of the threshold value, the AC electric motor control device is equipped with a threshold value detection mode for detecting said threshold value. In the threshold value detection mode, the rotor of the three-phase AC electric motor is once fixed by DC conduction, after which AC current is conducted between two phases to obtain said threshold value. |
