The report of optimisation of the hoisting winch system – the modernisation performed by FAMAK in Jaworzno.
The overhead travelling crane has been designed to carry loads up to 100t. The modernisation concerned all drivers of the overhead travelling crane, whereas this description concentrates on the hoisting winch system, which comprises two motors working on the common shaft.
The motor is powered by the VLT® AutomationDrive FC302 converter with a resistor 40%. The converter has been standard-programmed for hoisting winch systems. After a short optimisation, achieving the full holding torque during lifting/lowering posed no problems.
The optimisation range covered the main hoisting winch, as the auxiliary hoisting winch was working faultlessly. The basis for optimisation of the system working on the common shaft was application of the so called mechanical loadsharing, consisting in a virtual change of the motor characteristics, from the natural characteristics into more permissive ones, by introducing a negative compensation of slip and switching the converters into the work mode of the feedback open loop.
The slip compensation has been established at -300%. Full AMA has been conducted.
During the test, the hoisting winch was loaded with a mass of 30t, which is its work load.
No anomalies were observed in the work of the hoisting winch at this load.