| 摘要 |
PURPOSE:To improve paticularly the accelerating torque characteristic by comparing an output frequency with a command frequency, and selecting the optimum f/V pattern for the modes of accelerating, normal and decelerating operations of a motor. CONSTITUTION:An output frequency f0 is compared by a frequency comparator 14 with a command frequency fi, a suitable f/V pattern in response to the mode of acceleration or normal operation, and a voltage command V0 is outputted along the f/V pattern. The switching pattern of a variable control element 5 is decided in response to the output frequency f0 and the voltage command V0 by a switching processor 12, and the signals of the output frequency f0 and the voltage command V0 are outputted to a motor by an inverter main circuit on the basis of the switching pattern. Thus, preferable acceleration torque is available at the accelerating time, the suitable exciting operation is enabled at the normal time, and the preferable decelerating response is enable at the decelerating time. |
