The exact rotor position is required while a permanent magnet brushless servo motor (PMBSM) is under commutation and control. Howere, position sensors have some fatal defects.

永磁无刷伺服电机的换相和控制都需要准确的转子位置信息，然而位置传感器有其难以克服的缺点。

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The exact rotor position is required while a brushless DC motor (BLDCM) is under commutation and control. Howere, posi2 tion sensors have some fatal defects.

无刷直流电机的换相和控制都需要准确的转子位置信息，然而安装转子位置传感器有其难以克服的缺点。

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But a fatal accident inquiry which heard evidence of the position in which the bodies were found, determined all of the victims had been leaving the ground.

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