Optimizing current control performance in double winding asynchronous motors in large power inverter drives

The operation of ac drives in applications requiring high overload capability imposes hard working conditions on the electronic switching devices. The use of induction motors with two stator windings, fed by two inverter modules, allows large power rating in variable speed drives for high performance applications. This paper shows the structure and the main features of a field-oriented control for a double winding motor, fed by two GTO inverters. The operational results of a 850 kW drive, working as a melt pump in a polyethylene plant, are reported in order to describe the obtained performances.