| 摘要 |
PURPOSE:To enable control during idling or slippage by arranging an inverter for controlling a group of induction motors in plural blocks and calculating an inverter frequency command value based on a calculated inverter frequency and a slip frequency command value. CONSTITUTION:Speeds 64, 66, 68, 70 of induction motors 20, 22, 24, 26 are detected through detectors 28, 30, 32, 34, then the highest speed is employed as a reference speed and fed to a rotor frequency operating circuit 50 and an idling/slippage detecting circuit 54. During idling or slippage, speed frequency (fr) is fed as a rotor frequency (fr) to an inverter control circuit 58 from a speed generator output circuit 52. The circuit 58 calculates an inverter frequency command value fINV based on the frequency fr and a slip frequency command value is thus controlling an inverter 16. By such arrangement, control can be made during idling or slippage. |
