| 摘要 |
PURPOSE:To control the speed of an induction motor with high performance without directly detecting a speed and a motor voltage by so adjusting as to set a deviation between a command value of a motor voltage component and the output from a magnetizing current adjustor to zero. CONSTITUTION: E calculator 30 in an adjusting loop 300 obtains the calculated value of an M-axis component voltage of a voltage vector from a torque current, command values i'T, i'M of magnetizing currents and a motor constant, and outputs a deviation E from the output V''M of a magnetizing current adjustor 6. Since the E is generated due to the difference of a presumed speed value and an actual speed value and the noncoincidence in magnetic flux axes, this deviation E is input to an adjustor 25 in the loop 300, an adjusting loop in which the E always becomes zero is formed, thereby calculating its speed. |
