Abstract: A rotor includes S-pole and N-pole magnets which are arc-shaped in cross-section. Each pole has three magnets. Each magnet is embedded in the rotor in such a way that a convex side portion thereof faces center Or of the rotor. Distance Rs between center Os of circular arcs of S-pole magnets and center Or of the rotor is different from distance Rn between center On of circular arcs of N-pole magnets and center Or of the rotor (Rs?Rn). The ratio of the two distances is 0.92 (Rs/Rn=0.92). An outer peripheral section of an innermost-layer S-pole magnet is disposed in such a way as to protrude into an adjacent pole zone N1 or N2 from a pole zone S1 or S2.

Abstract: A control device 50 that drives and controls a brushless motor 3 of a four-pole 24-slot configuration includes: a base current calculation section 52 that calculates fundamental-wave current indicating a winding current value associated with maximum torque control; a correction component calculation section 59 that calculates 12th-order first higher harmonic wave component B sin 12(?+?) to cancel a torque ripple of magnet torque, and 12th-order second higher harmonic wave component A sin 12(?+?) to cancel a torque ripple of reluctance torque, based on a phase current value detected by a current sensor 64; a correction map 58 in which relation between phase current and parameters A, B, ?, and ? of the both higher harmonic wave components is stored; and a current correction section 60 that corrects supply current by superimposing each 12th-order higher harmonic wave component on the fundamental-wave current in order to create current command values Id? and Iq?.

Abstract: A control device 50 that drives and controls a brushless motor 3 of a four-pole 24-slot configuration includes: a base current calculation section 52 that calculates fundamental-wave current indicating a winding current value associated with maximum torque control; a correction component calculation section 59 that calculates 12th-order first higher harmonic wave component B sin 12(?+?) to cancel a torque ripple of magnet torque, and 12th-order second higher harmonic wave component A sin 12(?+?) to cancel a torque ripple of reluctance torque, based on a phase current value detected by a current sensor 64; a correction map 58 in which relation between phase current and parameters A, B, ?, and ? of the both higher harmonic wave components is stored; and a current correction section 60 that corrects supply current by superimposing each 12th-order higher harmonic wave component on the fundamental-wave current in order to create current command values Id? and Iq?.

Abstract: A rotor includes S-pole and N-pole magnets which are arc-shaped in cross-section. Each pole has three magnets. Each magnet is embedded in the rotor in such a way that a convex side portion thereof faces center Or of the rotor. Distance Rs between center Os of circular arcs of S-pole magnets and center Or of the rotor is different from distance Rn between center On of circular arcs of N-pole magnets and center Or of the rotor (Rs?Rn). The ratio of the two distances is 0.92 (Rs/Rn=0.92). An outer peripheral section of an innermost-layer S-pole magnet is disposed in such a way as to protrude into an adjacent pole zone N1 or N2 from a pole zone S1 or S2.