Hitachi Industrial Equipment Systems Co., Ltd.

Yuuta Iwase

Kenichi Saito

Yoshitaka Iwaji

Kazuaki Tobari

Yusaku Onuma

Masahiro Sano

Toshio Tomita

Provided is an AC electric motor control device capable of detecting, in an AC electric motor drive device, abnormal operation of an AC electric motor or abnormal operation due to, for example, a sudden change of a load without an erroneous operation regardless of the operational state of the AC electric motor. When driving a three-phase AC electric motor by an inverter, inside a controller, an electric motor constant is calculated using at least one of the current, voltage, and rotational speed of the electric motor and the variation of the constant value is analyzed, thereby detecting abnormal operation of the electric motor or abnormal operation of a load device connected to the electric motor. In order to analyze the constant, a variation to be determined to be abnormal is preset or an abnormal value is calculated in comparison with the accumulated values of past constant changes. Alternatively, only the variation of the constant calculated in the controller is extracted to detect abnormality.

AC electric motor control device

Provided are a data obtaining method, an inverter, and a rotating electric machine capable of managing the operation state of a device without complicating the configuration thereof. Therefore, the data obtaining method uses an inverter for controlling a synchronous electric motor, wherein a position/speed calculation unit of the inverter calculates an electric angle of the synchronous electric motor from the value of the current flowing between the synchronous electric motor and the inverter and obtains data for each electric angle by sampling internal data within the inverter, said internal data being used for controlling the synchronous electric motor in synchronization with the information of the electric angle.

Data obtaining method, inverter, and rotating electric machine

Growing community of inventors

Tokyo, Japan

Yuuta Iwase