Scheme design of the electrical control system for ultra-deep （>10000 m） wireline coring winch based on PLC and Profinet fieldbus

Abstract:

In response to the risks such as traction failure， wire rope disorder and breakage faced by the 13000 m wireline core drilling winch during ultra-deep well operations， an electrical control system based on the Siemens S7-1500 PLC and Profinet fieldbus was designed. The system adopts a modular design， integrating AC variable frequency drive， multi-source information acquisition， and dynamic braking， and it features three operation modes， namely， local control， wireless remote control， and centralized control in the remote driller''s cabin. For key control strategies， the dual traction motors implement load balancing through master-slave control with "speed closed-loop synchronization + load distribution". A tension closed-loop PID control is constructed using pressure sensors of the slack compensator， enabling the line speed of the cable storage drum to automatically follow the traction speed and achieve constant-tension cable winding and unwinding. The cable arrangement mechanism employs encoder calculation and angle sensor measurement as redundant methods to realize precise position tracking and automatic direction reversal. In terms of hardware， a VFD room integrating the PLC control cabinet and frequency conversion cabinet was designed， equipped with industrial wireless remote control and an upper computer configuration interface. This system can effectively improve the control accuracy， operational flexibility， and operational safety of the winch， providing technical support for the research and development of ultra-deep wireline core drilling equipment. The control system scheme can serve as a technical foundation for enhancing the automation level and ensuring safe operations of wireline core drilling winches for the ultra-deep hole.