Hereinafter, the dimensional relationship of the permanent magnet 130 and the flux barriers 125, 126, 127, and 128 used in the interior permanent magnet motor 100 according to an embodiment of the disclosure will be described with reference to FIG. 11. For reference, because the plurality of permanent magnets 130 and the corresponding plurality of flux barriers 125, 126, 127, and 128 are formed identically, hereinafter, the dimensional relationship of the permanent magnet 130 and the flux barriers 125, 126, 127, and 128 will be described on the basis of one permanent magnet 130 and two flux barriers 125, 126, 127, and 128 provided on the both ends of the permanent magnet 130.

The pole arc angle θm of the permanent magnet 130 may be formed to satisfy the following formula. Here, the pole arc angle θm refers to an angle between two straight lines connecting the center C of the rotor 120 and the opposite ends of the permanent magnet 130.
θn≤θm<θm+θs/2
θn=360/P
θs=360/S

Here, P is the number of magnetic poles of the rotor 120, and S is the number of slots 115 of the stator 110.

Therefore, when the pole arc angle θm of the permanent magnets 130 satisfies the above condition, the effective magnetic flux amount may be maximized.

Further, the pole arc angle θm of the permanent magnet 130, the flux barriers 125, 126, 127, and 128, and the slots 115 of the stator 110 may be formed to satisfy the following relationship.
θs/2≤θib<θm<θob
θs/2≤θib<θn