Hitachi Industrial Equipment Systems Co., Ltd.

Masato Ohya

Kazuaki Tobari

Hiroshi Watanabe

Yoshitaka Iwaji

Yusaku Onuma

Hironori Ohashi

Takuya Sugimoto

Agnes Hadinata

A power converter apparatus comprising: a power converter that outputs signal to the magnet motor to vary the output frequency, output voltage and output current of the magnet motor, a control unit controls the power converter, wherein the control unit calculating the gain of the magnetic flux component of the q-axis, which varies with the phase of the magnet motor, calculating the d-axis induced voltage command value based on a value of the induced voltage coefficient, frequency estimates or frequency command value, and the gain of the flux component of the q-axis.

Power converter apparatus

According to the present invention, in position sensorless control for switching between a 120-degree energization scheme for a low-speed region and a 180-degree energization scheme for a mid-to-high-speed region, stable and highly accurate speed control characteristics are provided by suppressing speed deviation &#x394;&#x3c9;r in the low-speed region, and by preventing current jump-up caused by a discontinuous rotational speed occurring during switching to the mid-to-high-speed region. In the case of driving in the 120-degree energization scheme, a voltage command value is corrected such that an estimated speed value or a detected speed value follows a speed command.

Synchronous motor control apparatus

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Tokyo, Japan

Masato Ohya