speed control by static slip power recovery

• 串级调速

speed control by static slip power recovery的用法和样例：

例句

1. The machines are driven by hydraulic power with smooth transmission and their speed can be adjusted steplessly.
   本机床采用液压传动，工作平稳，能无级调速，并有超负荷保险装置。
2. The spindles motor uses electromagnetic stepless speed regulation ,and adapts to cutting for different materials.
   主轴电机电磁无级调速，适应不同材质的裁切。