The container transpor tation industr y has witnessed a remarkable growth over the last decade. Control system wise, the programmable logic controller (PLC) was the preferred solution for motion control and general interlocking. As technology evolved over the years, so have the cranes, which are now bigger, faster and more complex electrically. Siemens as the leading supplier for container crane drive systems now introduces an innovative drive and control system solution that offers crane builders, system integrators and end-users for the first time standardised yet flexible hardware and software solutions.
Crane controller standardisation
On the power electronic side, several developments have been seen through the years. However, on the programmable controller side, there has not been a major revolution in the philosophy of the control since the introduction of programmable logic controllers and field-bus systems as substitute for relay logic.
Siemens’ powerful centralised motion controller SIMOTIOND completely relieves the crane PLC from any technological crane drive task. This new approach (with internet connectivity) paves the way for a more effective approach to engineering, commissioning and troubleshooting. Key drive functions that are similar on any crane can be standardised and are available as tested and documented modules.
Crane builders and system integrators can now minimise the resources they require for development and maintenance of their own software blocks. End users gain the advantage that the core function modules are standard, independent of the crane manufacturer and the respective project team and also independent of the crane type, be it ship-to-shore, rail-mounted gantry, grab ship unloader, goliath or ladle crane, and ultimately the core function modules are standard.
Drive and control system availability is improved not only by the powerful internet-based diagnostic features of the new controller but also due to the quality of documentation and level of testing the standardised software functions.
Siemens’ DC thyristor converters (SIMOREG DC-MASTER) and AC drives (SIMOVERT MASTERDRIVES) with their crane-specific technology boards (T300 and T400) were widely accepted in the market. These technology boards provided cranespecific function blocks such as:
- Master-slave torque control
- Load-dependent field weakening
- Position sensing with synchronisation
- Limit switch handling
- Heavy load handling
- Slack rope control