| 摘要 |
This power conversion device identifies pull-out from the phase of a command voltage and the phase of a current produced as a result thereof and as such is not affected by either an induced voltage that becomes smaller at low speeds or current fluctuation due to a load, allowing stable pull-out detection. This power conversion device has a DC-voltage unit that smooths a DC voltage, a power conversion unit that converts said DC voltage to an AC voltage, a current acquisition unit that acquires the current flowing through the power conversion unit, an output computation unit that computes the output voltage of the power conversion unit from the current acquired by the current acquisition unit, and a pull-out determination unit that determines whether or not pull-out has occurred in a synchronous motor connected to the power conversion unit. The pull-out determination unit uses the difference between the phase of the current acquired by the current acquisition unit and the phase of the output voltage computed by the output computation unit to determine whether or not pull-out has occurred in the aforementioned synchronous motor. |
