| 摘要 |
In a motor control system in which an induction motor is driven by an inverter and the motor tends to resonate, the resonant frequency of the motor and the extent of its damping are adjusted to desirable amounts by a local feedback circuit. An output signal of the local feedback circuit is algebraically added to a speed command voltage for the motor control system. A sum signal thus produced is connected to the input of the inverter to control the motor speed. The sum signal is also employed as one of two input signals to the local feedback circuit, the second input signal being proportional to the speed of the rotor of the motor and obtained from a sensor connected with the rotor shaft. The two input signals to the local feedback circuit are subtracted and their difference signal is processed through a lag circuit and a filter network to produce the output signal of the local feedback circuit. When the inverter and motor are thus stabilized by the local feedback circuit just described, it is much easier to stabilize a larger speed-control feedback loop in which the inverter and motor may be employed. |
