A synchronous electrical machine includes a stator having a circumferential row of teeth carrying stator windings. The electrical machine further includes a coaxial rotor having a circumferential row of poles carrying field windings. Each pole has first and second side flanks and a tip surface which extends continuously there between to form an air gap to the teeth of the stator. On a transverse cross-section through the machine, one of the side flanks forms a leading edge of the pole, and the other side flank forms an opposite, trailing edge of the pole. Each pole carries a row of permanent magnets which extends across the tip surface from one of the side flanks to the other side flank, the permanent magnets compensating for armature magnetic reaction. The radial thickness of the permanent magnets increases smoothly with progressive distance across the tip surface from one of the side flanks to the other side flank.

A winding field rotor includes a rotor core having main pole portions arranged in a circumferential direction and protruding in a radial direction, and a field winding. The field winding has coil bodies formed by winding a conductor wire in multiple layers in the radial direction for each of the main pole portions, and each of the coil bodies is connected in series in the circumferential direction. Each of the coil bodies has an inner end at a position on a radially inner side of the coil body, and an outer end at a position on a radially outer side of the coil body. The inner end is connected to the inner end of another coil body adjacent to the coil body on one circumferential side, and the outer end is connected to the outer end of another coil body adjacent to the coil body on the other circumferential side.

A winding field rotor includes a rotor core having main pole portions arranged in a circumferential direction and protruding in a radial direction, and a field winding. The field winding has coil bodies formed by winding a conductor wire in multiple layers in the radial direction for each of the main pole portions, and each of the coil bodies is connected in series in the circumferential direction. Each of the coil bodies has an inner end at a position on a radially inner side of the coil body, and an outer end at a position on a radially outer side of the coil body. The inner end is connected to the inner end of another coil body adjacent to the coil body on one circumferential side, and the outer end is connected to the outer end of another coil body adjacent to the coil body on the other circumferential side.