| 摘要 |
PURPOSE:To control the instantaneous restarting of inverter driving of a plurality of motors simultaneously within the shortest period of time at all times by a method wherein the timing of the restarting of the operation is selected freely by the external operating signal of system operation irrespective of which is larger, an instantaneous service interruption time or an instantaneous service interruption guarantee time. CONSTITUTION:The speed 61a of a motor becomes free run from a time point (t0) by the interception of a power source and the signal level of a motor operating signal 81a is reduced from 'H' into 'L' from the time point (t0) while the motor operating signal 81a is built up from 'L' into 'H' at a time point (t4) by a time delay (t2-t3) in an inverter control circuit and a time delay (t3-t4) in the whole controller of a system at a time point (t2). When an instantaneous service interruption time (t) is larger than an instantaneous service interruption guarantee time T, the restarting of the operation of the motor can not be effected automatically in conventional examples, however, the motor speed 61a is accelerated from a frequency corresponding to a motor speed during the free run at the time point (t4) and is returned to a motor speed before service interruption is caused. |
