| 摘要 |
PURPOSE:To suppress the unstable phenomemon of a magnetic flux level and set responsiveness constant regardless of a rotational speed, by making the maximum value ratio of alpha-phase primary-voltage e1alpha larger as beta-phase primary- voltage e1beta is made less. CONSTITUTION:By the regulation of voltage e1beta' with an arithmetic circuit 17, voltage e1 is turned into a waveform modulated with the period (60 deg.) of a voltage vector, and then, current i1beta is set constant, and the torque pulsating of a motor 7 is controlled. Then, by voltage correction for making the maximum value ratio of primary voltage e1alpha with the specification of a range, larger as primary voltage e1beta is made 3 less, the unstable phenomenon of a magnetic flux level is suppressed. Besides, the output side of a speed controlling amplifier 9 is provided with a gain regulating circuit 20, and based in a dividing result between a magnetic flux level estimate lambda2alpha' and a set value lambda2alpha, which is found from current i1alpha and an induction machine constant, current i1beta' is corrected, and the positive gain of a control system is set constant, and responsiveness is set constant regardless of a rotational speed. |
