Composite excited alternating current exciter

The invention relates to a composite excited alternating current exciter which comprises a stator pole and a rotor. The rotor is arranged in the stator pole, an air gap is reserved between the rotor and the stator pole, the stator pole comprises a stator pole core, an exciting winding and a permanent magnet, the exciting winding is wound on the stator pole core, one of two magnetization surfaces of the permanent magnet contacts with the stator pole core, the other one of the magnetization surfaces of the permanent magnet contacts with the air gap, the surface of the permanent magnet contacting with the air gap does not interfere with the external circular surface of the rotor, and the direction of a magnetic field generated by the permanent magnet is consistent with that of a magnetic field generated by the exciting winding. As one of the two magnetization surfaces of the permanent magnet contacts with the stator pole core while the other one of the magnetization surfaces of the permanent magnet contacts with