Brushless motor, external AC voltage source, and electric power steering device

摘要

The present invention provides a brushless motor in which the voltage utilization ratio can be increased and the torque and output of the motor can thereby be increased, and also provides a drive method for a brushless motor. The brushless motor includes an armature constituted by an armature core having armature windings of a plurality of phases, and a field pole constituted by a field pole core having a plurality of permanent magnets. A voltage, in which at least a 5th order harmonic component is superimposed on a 1st order fundamental wave of a voltage under predetermined phase difference condition and amplitude condition in order to increase a 1st order fundamental wave peak of the applied voltage over an applied voltage peak, is applied to the armature windings.

主权项

1. A brushless motor comprising an armature constituted by an armature core having armature windings of a plurality of phases, and a field pole constituted by a field pole core having a plurality of permanent magnets, wherein
a voltage, in which at least either of a 5th order harmonic component and a 7th order harmonic component is superimposed on a 1st order fundamental wave of an applied voltage under a predetermined phase difference condition and an amplitude condition such that a 1st order fundamental wave peak of the applied voltage is made larger than an applied voltage peak, is applied to the armature windings; a harmonic voltage superimposed on the armature windings is the 5th order harmonic component; and the 5th order harmonic component has a phase difference of 150° to 210° with the 1st order fundamental wave of the voltage, where one period of the high-order harmonic component is taken as 360°, and a ratio of an amplitude of the 5th order harmonic component to an amplitude of the 1st order fundamental wave of the voltage is 2% to 12%.