直驱永磁同步风力发电机运行转速低，一般定子外径都比较大。

Direct-driven PMSG works at low speed and its size is generally big.

youdao

一旦电机达到接近设计运行转速，离心开关开始动作，关断启动绕组与电网之间的连接。

Once the motor reaches near design operating speed, the centrifugal switch activates, opening the contacts and disconnecting the startup winding from the power source.

youdao

改进后大大缩短了轴的长度，使轴的临界转速远在运行转速之上，泵由两个密封改为一个密封。

The modification resulted in a much shorter shaft with a critical speed well above the running speed, and a pump with only one instead of two seals.

youdao