| 摘要 |
A stator winding for an electrical machine (e.g. a motor or generator) has two or more coil groups (Group 1, Group 2), each coil group including a plurality of coils. The stator winding is connected to a power source 18 such as an ac supply, for example. The coil groups (Group 1, Group 2) are connected in series and to the power source 18 by a respective switch 26a, 26b so that one or more of the coil groups can be selectively supplied with power from the power source 18. The switches 26a, 26b are operated by a controller 32. |
