When power regeneration for energy saving was specified for Turkey’s biggest ever shipyard crane, the crane manufacturer, Vinçsan, had no hesitation in turning to their local Control Techniques Drive Centre for help.

The crane, recently built for the end-user Tersan Tersanecilik, a ship-builder who is in the process of fitting out a new state-of-the-art shipyard in Yalova in north-western Turkey, is believed to be the largest capacity overhead crane in the whole of Turkey.  It has a lifting capacity of 2x275 tonnes (SWL 550 tonnes), and will be in operation for 18 hours a day once the shipyard is in full production.

Solutions offered by other leading drives suppliers failed to meet the response time required for regeneration in the supply transient conditions of the site, whilst the Control Techniques scheme, based on three modular drives, gives the required performance.

The regeneration set-up comprises three paralleled Unidrive SPMD 1424 AC modular drives in regenerative mode, rated at 500kW and feeding all the motor drives on the crane.  The two main 275 ton hoisting motors, from Control Techniques’ sister company Leroy Somer, are driven by further SPMD1424 modular AC drives, an auxiliary hoisting motor is controlled by a 55kW Unidrive SP AC drive and a travel motor by a 44kW Commander SK AC drive.

There is a total of 20 crane travelling motors, which are electrically controlled in groups of five, each group being controlled by a modular SP 1421 drive. 

All of the drives are under the overall control of a master PLC that communicates with all of the drives by Profibus DP, each drive being fitted with a special SM module for this purpose.

The system features control of the brakes via the drive software and constant power hoisting via feedback from load-cells to prevent overload / over-speed.  During lowering operations, the system automatically moves into regeneration mode to feed energy back into the common bus system to provide significant savings in overall energy consumption.