A permanent-magnet synchronous motor comprising: a stator iron core having a plurality of teeth in an inner circumferential portion thereof and a space surrounded by the inner circumferential portion; an armature winding wound on every second tooth among the plurality of teeth; and a rotor that is inserted into the space of the stator iron core and has magnetic-field poles that are each composed of a permanent magnet, wherein the armature winding is separated into a first armature winding and a second armature winding that are independent from each other and are alternately wound on every second tooth among the plurality of teeth such that the first armature winding is wound on every fourth tooth and the second armature winding is wound on every fourth tooth, wherein the first armature winding is connected with a first control apparatus (14a, 18a, 19a, 20a, 21a, 22a) configured to detect a failure in the first armature winding, wherein the second armature winding is connected with a second control apparatus (14b, 18b, 19b, 20b, 21b, 22b) configured to detect a failure in the second armature winding, wherein driving can be performed by a first system including the first armature winding and the first control apparatus (14a, 18a, 19a, 20a, 21a, 22a) and a second system including the second armature winding and the second control apparatus (14b, 18b, 19b, 20b, 21b, 22b), and wherein, in a case where a failure occurs in one of the first system and the second system, the control apparatus of that system is configured to stop the driving by that system and the other system thereof is configured to continue the driving. a stator iron core having a plurality of teeth in an inner circumferential portion thereof and a space surrounded by the inner circumferential portion; an armature winding wound on every second tooth among the plurality of teeth; and a rotor that is inserted into the space of the stator iron core and has magnetic-field poles that are each composed of a permanent magnet, wherein the armature winding is separated into a first armature winding and a second armature winding that are independent from each other and are alternately wound on every second tooth among the plurality of teeth such that the first armature winding is wound on every fourth tooth and the second armature winding is wound on every fourth tooth, wherein the first armature winding is connected with a first control apparatus (14a, 18a, 19a, 20a, 21a, 22a) configured to detect a failure in the first armature winding, wherein the second armature winding is connected with a second control apparatus (14b, 18b, 19b, 20b, 21b, 22b) configured to detect a failure in the second armature winding, wherein driving can be performed by a first system including the first armature winding and the first control apparatus (14a, 18a, 19a, 20a, 21a, 22a) and a second system including the second armature winding and the second control apparatus (14b, 18b, 19b, 20b, 21b, 22b), and wherein, in a case where a failure occurs in one of the first system and the second system, the control apparatus of that system is configured to stop the driving by that system and the other system thereof is configured to continue the driving.