Pulse loss fault of high-speed closed-loop control encoder in DQ90BSC top drive
This study mainly focused on the hardware topology of the main motor drive control system of the Siemens S120 frequency converter for the DQ90BSC top drive.In speed closed-loop control mode,"F31118 encoder 1:speed difference exceeding tolerance"fault shutdown occurred on the top drive frequency converter when the top drive's given speed exceeded 120 r/min.Combining with the above phenomenon,further analysis was conducted on the principles of speed closed-loop and open-loop control,as well as the principles of speed closed-loop and open-loop mode switching.The speed and actual speed curves were analyzed in real time by the STARTER software's trace function.Actual feedback waveforms of encoder channels A and B were measured by oscilloscope.On this basis,reasons for pulse loss caused by electromagnetic interference in the encoder circuit were comprehensively analyzed.Then,according to EMC specifications,shielded twisted pair cables were purchased and the encoder circuit was relayed.Afterward,the problem of pulse loss in high-speed closed-loop control mode was completely solved,greatly improving equipment's stability and reliability in operation and reducing equipment downtime.
top drivehigh-speed closed-loop controlencoderpulse loss faultmaintenance
NETL
NSTL
万方数据
