Doubly fed electric machines, Doubly fed induction generator (DFIG), or slip-ring generators, are electric motors or electric generators, where both the field magnet windings and armature windings are separately connected to equipment outside the machine. By feeding adjustable frequency AC power to the field. .
Doubly fed electrical generators are similar to , but have additional features which allow them to run at speeds slightly above or below their natural synchronous speed. This is useful for large .
With its origins in with multiphase winding sets on the rotor and stator, respectively, which were invented by in 1888, the rotor winding set of the doubly fed electric machine is connected to a selection of resistors via multiphase. .
• Dufour, Christian; Bélanger, Jean (2004). (PDF). Archived from (PDF) on 2011-01-05. Retrieved 2011-02-17. {{}}: Cite journal requires |journal= ( .
Doubly fed induction generator (DFIG), a generating principle widely used in . It is based on an with a multiphase wound rotor and a multiphase assembly with brushes for access to the rotor windings. It is possible to avoid the.
[pdf] Energy in Afghanistan is provided by followed by and . Currently, less than 50% of 's has access to electricity. This covers the major in the country. Many rural areas do not have access to adequate electricity but this should change after the major project is completed.
[pdf] 斯瓦尔巴和扬马延（：Svalbard og Jan Mayen，：SJ，：SJM，：744）是定义的一片地区，由享有特殊司法权的挪威领土和组成。尽管这两个地方被国际标准组织被视为一体，但两者在行政上没有关联。斯瓦尔巴和扬马延拥有。联合国统计局.
[pdf] 
