Permanent magnet electrical rotating machine, wind power generating system, and a method of magnetizing a permanent magnet

A wind power generating system having a wind mill, an electrical rotating machine, which is accommodated in a nacelle, connected to the wind mill through a speed-up gear, and the electrical rotating machine which is connected to a power system through a power converter, wherein:

• the electrical rotating machine is provided with a permanent magnet, which is seated in a slot of a rotor disposed to face an inner periphery of a stator with a certain gap,
• the permanent magnet is disposed in a rotor iron core of the rotor along an outer periphery of the rotor iron core to face the inner periphey of the stator, polarities thereof being alternately changed;
• a cooling airflow channel is formed between adjacent poles on the rotor iron core, and extends to an axial direction of the rotor iron core and extends from the outer periphery of the rotor iron core, in a radial direction, to a radial center of the rotor iron core;
• and
• a cooling air is introduced in the cooling airflow channel by a fan connected to a shaft of the rotor, so that the cooling airflow channel receives and circulates the cooling air from the fan to the rotor iron core to cool the rotor during rotation,
• wherein the electrical rotating machine generates electric power in response to rotation of the wind mill in the wind power generating system.