Abstract: A synchronous electric motor having a structure for reducing cogging torque generated by the positioning error of a permanent magnet. Protrusions are alternately arranged in regions A and B in the circumferential direction of an iron core. Therefore, with respect to neighboring magnets positioned on both sides of the first protrusion, in region B, where the protrusion does not exit, ends of the neighboring magnets are attracted to each other by magnetic force. On the other hand, with respect to the neighboring magnets positioned on both sides of the second protrusion, in region A, where the protrusion does not exit, ends of the neighboring magnets are attracted to each other by magnetic force resulting in being inclined in opposing directions, and thus the generated cogging torque is significantly reduced.

Abstract: A synchronous electric motor having a structure for reducing cogging torque generated by the positioning error of a permanent magnet. Protrusions are alternately arranged in regions A and B in the circumferential direction of an iron core. Therefore, with respect to neighboring magnets positioned on both sides of the first protrusion, in region B, where the protrusion does not exit, ends of the neighboring magnets are attracted to each other by magnetic force. On the other hand, with respect to the neighboring magnets positioned on both sides of the second protrusion, in region A, where the protrusion does not exit, ends of the neighboring magnets are attracted to each other by magnetic force resulting in being inclined in opposing directions, and thus the generated cogging torque is significantly reduced.

Abstract: A motor control device that performs vector control to control a q-axis current and a d-axis current of a permanent magnet synchronous motor independent from each other. The motor control device includes a q-axis current and d-axis current detection unit configured to detect a q-axis current and a d-axis current of a permanent magnet synchronous motor, a q-axis current command value generation unit configured to generate a q-axis current command value, a d-axis current command value generation unit configured to generate a d-axis current command value, in which an amount of rise in the temperature of permanent magnets in a steady state of the permanent magnet synchronous motor is a minimum, and a drive unit configured to drive the permanent magnet synchronous motor.

Abstract: A motor control device that performs vector control to control a q-axis current and a d-axis current of a permanent magnet synchronous motor independent from each other. The motor control device includes a q-axis current and d-axis current detection unit configured to detect a q-axis current and a d-axis current of a permanent magnet synchronous motor, a q-axis current command value generation unit configured to generate a q-axis current command value, a d-axis current command value generation unit configured to generate a d-axis current command value, in which an amount of rise in the temperature of permanent magnets in a steady state of the permanent magnet synchronous motor is a minimum, and a drive unit configured to drive the permanent magnet synchronous motor.