| 摘要 |
PROBLEM TO BE SOLVED: To expand the tolerance of a mounting error by controlling a current phase to the average value of the phase in the weakening field direction and strengthening field direction of a limit for assuring the required torque of a motor. SOLUTION: When a speed command ω* is outputted from a speed command device 61, a deviation Δω to an output signal ω of a speed detector 58 is inputted to a speed control device 62, and an output signal becomes a torque command signal T* of a synchronous motor 56 according to the deviation is inputted to a q-axis current command device 63 for calculating a q-axis current command Iq*. A although a d-axis current command device 64 calculates a d-axis current command Id*, the current phase is set to the average value of the phases in the direction of a weakening field and in the direction of a strengthening field of a limit, where the required torque of the synchronous motor 56 is assured. Then, both the axis current command signals Iq* and Ip* are inputted to a current control device 65 and to a PWM pulse generation device 66, PWM control is executed by a PWM pulse signal, and the output voltage and output frequency of an inverter 54 are controlled, thus expanding the tolerance for a mounting error. |
