| 摘要 |
<p>In an elevator having sheaves and motors for individually driving the sheaves, an abnormality of traction loss of the sheaves is prevented. A control device for an elevator has a main rope for connecting an elevator car and a counterbalance weight, sheaves on which the main rope is passed, motors for individually driving the sheaves, and speed control devices for individually controlling torque of the motors. The control device performs a required operation mode according to speed command values to the speed control devices. The control device further has an abnormality detection device for comparing torque command values of the speed control devices and, when the resultant difference exceeds a predetermined standard value, outputting an abnormality signal based on its determination that any one of the sheaves has traction loss. When the abnormality detection device outputs the abnormality signal, the control device changes a speed command value for each of the speed control devices according to an operation mode at which the abnormality signal is outputted.</p> |
