| 摘要 |
PURPOSE:To discriminate the efficiency of a motor on each number-of-poles based on torque and rotational frequency, and enable the switching of an optimum number-of-poles to be selected by comparing rotational frequency command and torque command with the contents of a characteristic table, and by generating the output of selecting signal for displaying the number-of-poles of high efficiency. CONSTITUTION:A number of poles changing controller 100 is provided with a means for comparison-discriminating the number-of-poles of the highest efficiency of a motor 10 based on torque command signal T* and rotational frequency command signal N. In other words, a control command section for directing the output of switching signal for selecting an optimum stator number-of-poles, to a number of poles changing section 102 for switching the stator number-of-poles of the induction motor, is provided with a characteristic table for storing efficiency characteristic according to rotational frequency and torque on each pole number of the induction motor, and a comparator 108 for generating the output of selecting signal for comparing rotational frequency command and torque command with the contents of the characteristic table and displaying the number-of-poles of high efficiency. As a result, based on the torque and rotational frequency of the induction motor, the optimum stator number-of-poles can be selected to be switched. |
