Through electromagnetic induction, excitation current is transferred from primary side to secondary side.Advantages are: high efficiency, simple fabricating technique, and quick demagnetization.

• 这种无刷励磁同步电机的励磁电流是通过电磁感应从旋转变压器的初级传递到次级的，故这种无刷励磁同步电机的效率高、制造工艺简单、成本较低、灭磁快。