A high efficiency control of interior permanent magnet motor

In this paper, we propose a technique to realize a high efficiency drive for a IPM (interior permanent magnet) motor in normal speed region. In this method, we pay attention to the torque equation of the IPM motor. We realize high efficiency drive by controlling the vector angle of the stator current. As for the high efficiency control, we define the optimum angle as the stator current angle which makes the torque biggest about a certain stator current value. The optimum angle is shown as the equation about the stator current value. In addition, we propose the methods to find out the optimum angle for the real system by changing the stator current angle around the calculating optimum angle in the low frequency. This technique is realized by uniting between the motor drive region and the mechatronics control region. By using this technique, we can detect a high efficiency optimum angle.