| 摘要 |
PROBLEM TO BE SOLVED: To generate flat state in the torque characteristic of a brushless motor. SOLUTION: When the number of poles (number of slots) of a stator is 6 and a number of poles (number of permanent magnets) of a rotor is 8 in a three-phase brushless motor, the coil current of each phase is shifted by a phase at each 12 deg. for electrical angle (mechanical angle of 30 deg.), and also the coil current of each phase is switched in a step state at the same time with three phases by each 60 deg. of electrical angle (mechanical angle of 15 deg.). Here, when I is the coil current for one phase maximized of the three phases, the coil current of the rest of two phases is controlled so as to be -I/2 respectively. In a brushless motor other than the above number of poles, an angle θ switched in a step state of the coil current of each phase is set to 360/N [ deg.] (where, N is the least common multiple of number of poles of stator and rotor) of mechanical angle. In this way, a flat torque characteristic can be obtained over full angle range. |
