Non-conventional application of AC drives - Use of AC drives in emergency systems. Case study: tilting system of torpedo car in CST BOF shop

Nowadays, variable speed drives (VSD's) are very often used in many industrial systems, but almost always in traditional applications. This paper describes the successful application of VSD's in the CST-Arcelor Brasil torpedo car tilting system in the basic oxygen furnace BOF (steelmaking plant), in normal operation condition and also in emergency system condition during blackouts. The electrical system uses a 440 V
_AC
three-phase induction motor. During a blackout, the VSD is fed by DC accumulators battery bank (456 V
_DC
) in order to put the system in a safety position. The paper presented the new topology for this system, describing the techniques employed, the benefits and the latest results