| 摘要 |
A control system for an electric motor provided with a speed or magnetic flux control means for performing feedback control of speed or field flux of an electric motor in accordance with speed reference or magnetic flux reference. The control system provided with the speed control means further comprises a rate limiting circuit (31) and a change-over circuit (30) effectively acting on the limiting circuit to operate the same in response to the operating condition of the speed control means with reference to the reference value. The control system provided with the flux control means further comprises a first-order lag filter (40) and a change-over circuit (41) effectively acting on the first-order lag filter to operate the same in response to the operating condition of the magnetic flux control means with reference to the reference value. In both control modes, when the speed control means or magnetic flux control means is switched from "OFF" state to "ON" state, the rising of the speed or voltage can be achieved safely and effectively for a short time without failure. |
