section_path: Externally commutated AC machine
section_name: Externally commutated AC machine
paragraph_text: Externally commutated AC machine
  
  AC induction and synchronous motors are optimized for operation on single-phase or polyphase sinusoidal or quasi-sinusoidal waveform power such as supplied for fixed-speed applications by the AC power grid or for variable-speed application from variable-frequency drive (VFD) controllers.